Twin Disc HP 300, 600 service manual - Morbark

TWIN TWIN DISC 

DISC 

INCORPORA 

INCORPORATED 

INCORPORA TED 

Ser Service Ser vice 

Manual 

Manual 

Hy Hydr Hy dr draulic dr aulic 

Power er Tak ak ake-of ak e-of e-off e-of 

Model: 

HP300 Series 

HP600 Series 

Document Number: 1021542

NOTICE 

Twin Disc, Incorporated makes no warranty or guaranty of any kind, 

expressed, implied or otherwise, with regard to the information contained 

within this manual. Twin Disc, Incorporated has developed this manual 

through research and testing of the information contained therein. Twin 

Disc, Incorporated assumes no responsibility for any errors that may 

appear in this manual and shall not be liable under any circumstances 

for incidental, consequential or punitive damages in connection with, or 

arising out of, the use of this manual. The information contained within 

this manual is subject to change without notice.

Hydraulic Power Take-off Service Manual 

Document Number 

1021542 

Issued 

August, 2004 

Hydraulic Power Take-off 

Service Manual 

3

REVISION AND REISSUE DATA 

Original Issue August, 2004 

BEFORE YOU START 

This manual replaces: 

Preliminary Manual #1021542 dated January, 2004 for use with 

Hydraulic Power Take-Off model HP300 & HP600. 

4 Hydraulic Power Take-off Service Manual

A. Twin Disc, Incorporated warrants all assembled products and parts, (except component products or parts 

on which written warranties issued by the respective manufacturers thereof are furnished to the original 

customer, as to which Twin Disc, Incorporated makes no warranty and assumes no liability) against defective 

materials or workmanship for a period of twenty-four (24) months from the date of original shipment by Twin 

Disc, Incorporated to the original customer, but not to exceed twelve (12) months of service, whichever 

occurs first. This is the only warranty made by Twin Disc, Incorporated and is in lieu of any and all other 

warranties, express or implied, including the warranties of merchantability or fitness for a particular purpose 

and no other warranties are implied or intended to be given by Twin Disc, Incorporated. 

The original customer does not rely upon any tests or inspections by Twin Disc, Incorporated or on Twin 

Disc, Incorporated*s application engineering. 

B. The exclusive remedy provided by Twin Disc, Incorporated whether arising out of warranty within the applicable 

warranty period as specified, or otherwise (including tort liability), shall at the sole option of Twin Disc, 

Incorporated be either the repair or replacement of any Twin Disc, Incorporated part or product found by 

Twin Disc, Incorporated to be defective and the labor to perform that work and to remove and reinstall (or 

equivalent credit). In this context, labor is defined as the flat rate labor hours established by Twin Disc, 

Incorporated in the published Twin Disc Flat Rate Schedule, required to remove, disassemble, inspect, 

repair, reassemble, reinstall and test the Twin Disc, Incorporated product only. Under no circumstances, 

including a failure of the exclusive remedy, shall Twin Disc, Incorporated be liable for economic loss, 

consequential, incidental or punitive damages. The above warranty and remedy are subject to the following 

terms and conditions: 

1. Complete parts or products upon request must be returned transportation prepaid and also the claims 

submitted to Twin Disc, Incorporated within sixty (60) days after completion of the in-warranty repair. 

2. The warranty is void if, in the opinion of Twin Disc, Incorporated, the failure of the part or product resulted 

from abuse, neglect, improper maintenance or accident. 

3. The warranty is void if any modifications are made to any product or part without the prior written consent of 

Twin Disc, Incorporated. 

4. The warranty is void unless the product or part is properly transported, stored and cared for from the date of 

shipment to the date placed in service. 

5. The warranty is void unless the product or part is properly installed and maintained within the rated capacity 

of the product or part with installations properly engineered and in accordance with the practices, methods 

and instructions approved or provided by Twin Disc, Incorporated. 

6. The warranty is void unless all required replacement parts or products are of Twin Disc origin or equal, and 

otherwise identical with components of the original equipment. Replacement parts or products not of Twin 

Disc origin are not warranted by Twin Disc, Incorporated. 

C. As consideration for this warranty, the original customer and subsequent purchaser agree to indemnify and 

hold Twin Disc, Incorporated harmless from and against all and any loss, liability, damages or expenses for 

injury to persons or properly, including without limitation, the original customer*s and subsequent purchaser*s 

employees and property, due to their acts or omissions or the acts or omissions of their agents, and employees 

in the installation, transportation, maintenance, use and operation of said equipment. 

D. Only a Twin Disc, Incorporated authorized factory representative shall have authority to assume any cost or 

expense in the service, repair or replacement of any part or product within the warranty period, except when 

such cost or expense is authorized in advance in writing by Twin Disc, Incorporated. 

E. Twin Disc, Incorporated reserves the right to improve the product through changes in design or materials 

without being obligated to incorporate such changes in products of prior manufacture. The original customer 

and subsequent purchasers will not use any such changes as evidence of insufficiency or inadequacy of 

prior designs or materials. 

F. If failure occurs within the warranty period, and constitutes a breach of warranty, repair or replacement parts 

will be furnished on a no-charge basis and these parts will be covered by the remainder of the unexpired 

warranty which remains in effect on the complete unit. 

January 16, 2002 TDWP0002 


TWIN TWIN TWIN DISC DISC, DISC INCORPORA 

INCORPORATED 

INCORPORA TED 

EX EXCL EX CL CLUSIVE CL USIVE LIMITED LIMITED WARRANTY 

ARRANTY 

GENERAL GENERAL UNITS 

UNITS 

5

6 Hydraulic Power Take-off Service Manual

Twin Disc, Incorporated Table of Contents 


Table of Contents 

Introduction .........................................................11 

General Information .......................................................................... 11 

Replacement Parts ............................................................................ 12 

Preventive Maintenance/Troubleshooting .................................... 13 

Safety .................................................................................................. 14 

Sources of Service Information ...................................................... 15 

Warranty.............................................................................................. 15 

Description and Specifications .........................17 

General Information .......................................................................... 17 

Identifying the HPTO model, serial and BOM numbers ............... 18 

Construction Features...................................................................... 19 

Specifications .................................................................................... 21 

Maximum safe operating speed ................................................. 21 

Approximate dry weight ............................................................... 21 

Oil Cooling requirements ............................................................. 21 

Oil type and oil viscosity .............................................................. 21 

Oil sump-basic information ......................................................... 22 

Oil scavenge pump, oil pump information ................................ 22 

Oil pressure specifications ......................................................... 22 

Fittings, Hose types ...................................................................... 24 

Electronic Module......................................................................... 24 

Output and Input speed sensor air gap..................................... 24 

Torque on input and output speed sensor nuts ...................... 24 

Remote mounted electronic control cable ................................ 24 

Shim tolerance for bearing carrier in idler gear ....................... 24 

Twin Disc PTO support plate specifications ................................. 25 

Torque values for U.S. fasteners..................................................... 26 

Wear limits .......................................................................................... 29 

Operation..............................................................31 

General................................................................................................ 31 

General Overview of GP Control Valve with Electronic Interface 32 

7


8 

Twin Disc, Incorporated 

GP Control Valve hydraulic portion ................................................ 33 

Hydraulic System with GP Control Valve ....................................... 36 

GP Control Valve Electronic Control Interface (Profile Module) ....... 38 

Clutch Engagement Logic (Closed Loop) ...................................... 39 

Brake engagement ....................................................................... 39 

Power Take-off Clutch engagement........................................... 39 

Installation............................................................41 

Identifying the Twin Disc Power Take-off Model Number............ 41 

Identifying the SAE Housing Size .................................................... 42 

Prior to Installation ............................................................................ 43 

Preliminary Checks ........................................................................... 44 

Torsional Input Coupling Installation ............................................. 47 

HPTO Installation to Engine ............................................................ 51 

Final Checks....................................................................................... 56 

Check and Adjust Main Pressure ............................................... 56 

Check Clutch Operation Pressures ........................................... 58 

Plumbing - HP300I, HP300S, HP300S, HP600S .............................. 59 

Maintenance .........................................................61 

Allowable Side Loads........................................................................ 61 

Lubrication ......................................................................................... 64 

Grease Specifications .................................................................. 64 

Oil Specifications .......................................................................... 65 

Oil System ...................................................................................... 65 

Torsional Coupling............................................................................ 66 

Overhaul Interval ............................................................................... 67 

Periodic Visual Inspection........................................................... 67 

Deflection Alignment Adjustment .................................................... 68 

Alignment - U-Joint Installation ........................................................ 70 

Disassembly ........................................................73 

Power Take-off Removal From The Engine ................................... 73 

Remove and disassemble the GP Control Valve .......................... 75 

Remove the Coupling Housing and disassemble 

the Gear Towers ............................................................................ 76 

Hydraulic Power Take-off Service Manual

Twin Disc, Incorporated Table of Contents 

Remove and Front Housing from the Clutch Housing ................. 78 

Disassemble the Clutch Housing .................................................... 79 

Cleaning and Inspection ....................................83 

Cleaning and Inspection................................................................... 83 

Assembly..............................................................89 

Clutch Shaft and Clutch Housing Assembly .................................. 90 

Clutch housing .............................................................................. 90 

Clutch shaft .................................................................................... 90 

Belt Sheave Housing Assembly .................................................... 100 

Clutch Assembly .............................................................................. 105 

Clutch piston, piston carrier and back plate unit ................... 109 

Clutch hub, clutch plates and gear & ring assembly ............ 117 

Assemble the Front Housing Unit/Install the Idler Gear ............. 124 

Install the Front Housing on the Clutch Housing ........................ 131 

Coupling housing ....................................................................... 132 

Assemble the Gear Drive Towers ................................................. 135 

General information.................................................................... 135 

Tower #1....................................................................................... 136 

Tower #2....................................................................................... 143 

Assemble the Control Valve Assembly......................................... 144 

Install the Speed Sensor Pickups ................................................. 151 

Output speed sensor.................................................................. 151 

Input speed sensor..................................................................... 152 

Install the Pump ............................................................................... 153 

Plumbing........................................................................................... 154 

HPTO Series Parts Identification List ........................................... 156 

Cross Section Views: 

HP300I & HP600I .......................................................................... 158 

HP300S & HP600S ....................................................................... 159 

Exploded Views and Illustrations: 

HP300S & HP600S Sheave Housing Front Bearing Area ...... 160 

HP300S & HP600S Sheave Housing Output Bearing Area.... 161 

HP300I & HP600I Rear Bearing Area......................................... 162 

HP300I, HP600I, HP300S, HP600S Clutch Area ....................... 163 

HP300I, HP600I, HP300S, HP600S Front Bearing Area .......... 164 


9


10 


HP300I, HP600I, HP300S, HP600S Idler Gear Area ................. 165 

HP300I, HP600I, HP300S, HP600S Tower #1 Area................... 166 

HP300I, HP600I, HP300S, HP600S Tower #2 Area................... 167 

HP300I, HP600I, HP300S, HP600S 

GP Control Valve Area Illustration ....................................... 168 


GP Control Valve Area Exploded View (Valve 1020729) ... 169 


GP Control Valve Area Exploded View (Valve 1021658) ... 170 

HP300I, HP600I, HP300S, HP600S Pipes and Fittings ............ 171 

HP300I, HP600I, HP300S, HP600S Pipes and Fittings ............ 172 

Troubleshooting................................................173 

Troubleshooting of GP Control Valve & Electronic Interface ... 173 

Troubleshooting Charts ................................................................. 174 

Engineering Drawings ......................................177 

List of Engineering Drawings ........................................................ 177 

Twin Disc Hydraulic Power Take-off Cut-away illustration ....... 178 

102668G Sheet 2 of 3: HP300I ........................................................ 179 

102668G Sheet 3 of 3: HP300I ........................................................ 180 

102668B Sheet 2 of 3: HP300S ...................................................... 181 

102668B Sheet 3 of 3: HP300S ...................................................... 182 

102668F Sheet 2 of 3: HP600I ........................................................ 183 

102668F Sheet 3 of 3: HP600I ........................................................ 184 

102668C Sheet 2 of 3: HP600S ...................................................... 185 

102668C Sheet 3 of 3: HP600S ...................................................... 186 

1020696: Control Valve Assembly ................................................ 187 

1020686: HPTO Control Module.................................................... 188 

1021292 Sheet 1 of 3: HPTO Plumbing......................................... 189 



1021295: Plumbing Schematic ...................................................... 192 


Twin Disc, Incorporated Introduction 

General Information 


Introduction 

This publication provides the information necessary for the operation and 

maintenance of the Twin Disc, Incorporated equipment specified on the cover 

of this manual. Specific engineering details and performance characteristics 

can be obtained from the Product Service Department of Twin Disc, 

Incorporated, Racine, Wisconsin, USA. 

Operation and maintenance personnel responsible for this equipment should 

have this manual at their disposal and be familiar with its contents. Applying 

the information in the manual will result in consistent performance from the 

unit and help reduce downtime. 

11

Introduction 

Replacement Parts 

12 

Parts Lists 


See the engineering assembly drawings in Engineering Drawings and parts 

identification and exploded views in the Assembly section to facilitate ordering 

spare or replacement parts. 

Ordering Parts 

All replacement parts or products (including hoses and fittings) must 

be of Twin Disc origin or equal, and otherwise identical with components 

of the original equipment. Use of any other parts or products will void 

the warranty and may result in malfunction or accident, causing injury 

to personnel and /or serious damage to the equipment. 

Renewal parts and service parts kits may be obtained from any authorized 

Twin Disc distributor or service dealer. 

Parts Shipment 

Note: Do not order parts from the part numbers on the crosssectional 

drawings. These numbers may be referenced 

for part identification; however, they should be verified 

on the bill of material (BOM) before an order is placed. 

BOM numbers are stamped on the unit nameplate. 

Furnish the complete shipping information and postal address. All parts 

shipments made from the factory will be FOB factory location, USA. State 

specifically whether the parts are to be shipped by freight, express, etc. If 

shipping instructions are not specified, the equipment will be shipped the 

best way, considering time and expense. Twin Disc, Incorporated will not be 

responsible for any charges incurred by this procedure. 

Twin Disc, Incorporated having stipulated the bill of material number on the 

unit’s nameplate absolves itself of any responsibility resulting from any 

external, internal or installation changes made in the field without the express 

written approval of Twin Disc. All returned parts, new or old, emanating from 

any of the above-stated changes will not be accepted for credit. Furthermore, 

any equipment which has been subjected to such changes will not be covered 

by a Twin Disc warranty. 



Preventive Maintenance/Troubleshooting 

Refer to the maintenance and troubleshooting sections of this manual. 

Frequent reference to the information provided in this manual regarding daily 

operation and limitations of this equipment will assist in obtaining troublefree 

operation. Schedules are provided for the recommended maintenance 

of the equipment and, if observed, minimum repairs (aside from normal wear) 

will result. 

In the event a malfunction does occur, a troubleshooting table is provided to 

help identify the problem area and lists information that will help determine 

the extent of the repairs necessary to get a unit back into operation. 

Lifting Bolt Holes 

Most Twin Disc products have provisions for attaching lifting bolts. The holes 

provided are always of adequate size and number to safely lift the Twin Disc 

product. 

These lifting points must not be used to lift the complete power unit. 

Lifting excessive loads at these points could cause failure at the lift 

point (or points) and result in damage or personal injury. 

Select lifting eyebolts to obtain maximum thread engagement with bolt 

shoulder tight against housing. Bolts should be near but should not 

contact bottom of bolt hole. 


13

Introduction 

Safety 

14 

General 


Safe practices must be employed by all personnel operating and servicing 

this unit. Twin Disc, Incorporated will not be responsible for personal injury 

resulting from careless use of hand tools, lifting equipment, power tools, or 

unaccepted maintenance/operating practices. 

Important Safety Notice 

Because of the possible danger to person(s) or property from accidents which 

may result from the use of manufactured products, it is important that correct 

procedures be followed. Products must be used in accordance with the 

engineering information specified. Proper installation, maintenance, and 

operation procedures must be observed. Inspection should be made as 

necessary to assure safe operations under prevailing conditions. Proper 

guards and other suitable safety codes should be provided. These devices 

are neither provided by Twin Disc, Incorporated nor are they the responsibility 

of Twin Disc, Incorporated. 

To prevent accidental starting of the engine when performing routine 

transmission maintenance, disconnect the battery cables from the 

battery and remove ignition key from the switch. 



Sources of Service Information 

Warranty 

Each series of manuals issued by Twin Disc, Incorporated is current at the 

time of printing. When required, changes are made to reflect advancing 

technology and improvements in state-of-the-art. 

Individual product service bulletins are issued to provide the field with 

immediate notice of new service information. 

For the latest service information on Twin Disc products, contact any Twin 

Disc distributor or service dealer. This can be done on the Twin Disc corporate 

web site found at [http://www.twindisc.com]. Provide your model number, 

serial number and bill of material number to obtain information on your unit. 

If necessary, contact the Product Service Department of Twin Disc, 

International S.A., Nivelles, Belgium, or Twin Disc, Incorporated, Racine, 

Wisconsin, 53405-3698, USA by e-mail at service@twindisc.com. 

Equipment for which this manual was written has a limited warranty. For 

details of the warranty, refer to the warranty statement at the front of this 

manual. 


15

Introduction 

16 



Twin Disc, Incorporated Description and Specifications 



Description and Specifications 

The Twin Disc Hydraulic Power Take-Off (HPTO) is an engine-mounted 

hydraulic power take off that contains an integral clutch for engagement of 

the PTO, and a brake to keep the output shaft stopped when the clutch is 

not engaged. Some models include an engine driven multiple pump drive to 

provide hydraulic fluid for operation of the pto, and other customer 

requirements. 

These Power Take Offs are controlled by hydraulics through the electronic 

control module. Both the clutch and the brake are operated by main pressure 

oil supply. The bearings, clutches, and gears are lubricated and cooled with 

low pressure oil. The output end bearing on “straddle” units is grease 

lubricated. 

17


18 

Identifying the Twin Disc Hydraulic Power Take-Off Model Number 


The nameplate identifies the model, bill of material (BOM) and the serial 

number of the unit. These numbers are necessary to identify the correct 

parts for your transmission. 



Construction Features 

Housings 

Bearings 

The HPTO housing consists of a front SAE 1 or SAE 0 engine housing 

adapter, and a front and rear housing. The front and rear housings are sealed 

together with a gasket. Straddle units have a rear bearing support housing. 

The input end and pump drive bearings are a combination of ball and 

cylindrical roller bearings. The rear main housing bearings are either 

spherical, tapered or cylindrical roller bearings. The rear bearing on straddle 

type units is a grease lubricated cylindrical roller design. 

Oil Pump Drive 

The oil pump is spline driven by the pump drive gear. Customer supplied 

auxiliary oil pumps can also be driven by the splined adapters in the pump 

drive gears. 

Lubrication Features 

Oil is directed by the control valve through horizontal drillings in the main 

shafts to orifices through which the front and rear bearings on the main shaft 

are lubricated. There are also orifices in the shafts through which both clutch 

and brake are cooled. The pump drive gears are lubricate by orifices in an 

external plumbing circuit. The rear bearing on straddle type units must be 

grease lubricated externally. 

Suction Strainer and Baffle 

A customer supplied serviceable suction strainer should be located between 

the customer supplied oil sump and the oil pump. A customer-supplied baffle 

installed in the sump allows aerated oil to settle prior to recirculation. 


19


20 

Filter Assembly 

Gears 


A customer supplied oil filter must be installed between the heat exchanger 

and the control valve. The filter must have a Beta removal efficiency rating 

of 2/20/75 for particle sizes 5 micron/13 micron/16 micron. A typical filter 

element should say 5 micron nominal or 16 micron absolute. 

All gears are hardened spur gears, and are in constant mesh. 

Flexible Torsional Input Coupling 

The purpose of the torsional coupling is to transmit power from the engine to 

the Power Take Off through a rubber or silicone element that will: 

� Dampen torsional vibrations. 

� Change the natural frequencies of a system to move critical 

frequencies out of the operating speed range. 

� Accommodate a certain amount of misalignment. 

� Absorb shock and reduce noise. 

� Minimize gear “rattle.” 

Heat Exchanger 

The customer supplied heat exchanger is required to maintain the oil in the 

hydraulic system of the Hydraulic Power Take Off at the proper temperature. 

An air to oil cooler is typical. 

The heat exchanger should be capable of dissipating 28,000 BTU/ hr. 

Recommended inlet temperature of heat exchanger: 170 o F. (77 o C.) 

Recommended outlet temperature of heat exchanger: 150 o F. (66 o C.) 

Oil flow from standard Twin Disc pump is 0.0085 gal/rev. 

Customer-supplied Support Plate Requirement 

Twin Disc, Inc. requires that a support plate be used with all HPTOs. 

See specifications and figure 2 of this manual. 



Specifications 

Maximum Safe Operating Speed for Twin Disc Hydraulic Power Take-offs 

HP300I (in-line) 2100 RPM 

HP300S (straddle-bearing) 2100 RPM 

HP600I (in-line) 2100 RPM 

HP600S (straddle-bearing) 2100 RPM 

Approximate Dry Weight 

Approximate Dry Weight: 590 Kg. (1,300 Lbs.) 

Oil Cooling Requirements (see engineering drawing for additional specs.) 

Customer supplied, air to oil cooling is typical. 

Minimum oil temperature at start up: -40 o C. (-40 o F.) 

Oil temp. at steady operating conditions: 66 o C.- 85 o C.(150 o F.-185 o F.) 

Maximum oil sump temperature: 93 o C. (200 o F.) 

Oil Type and Oil Viscosity 

Oil type and viscosity: 

SAE-API service class CD or CC engine oil certified to meet Caterpillar TO- 

2 transmission oil specification and/or Allison type C-4 transmission fluid. A 

10W, 30W, or 40W can be used, dependent on ambient temperature. See 

table 1. 


Note: If SAE 40 viscosity oil is used, all three drain lines 

must be used. 

Note: Multi-viscosity oils (i.e. 10W-30W, etc.) can be used 

under certain conditions, but require TWIN DISC 

approval. 

Table 1 - Recommended Oil Viscosity 

Ambient Start-up 

Temperature 

Steady Operating 

Temperature 

Suggested Oil 

Viscosity 

-40O C. 38OC. to 66OC. SAE 10 

-40O F. 100OF. to 150OF. SAE 10 

2O C. 49OC. to 77OC. SAE 30 

35O F. 120OF. to 170OF. SAE 30 

>40O C. 60OC. to 85OC. SAE 40 

>50O F. 140OF. to 185OF. SAE 40 

21


22 


Oil Sump-Basic Information (See engineering drawing for additional 

specs.) 

Capacity: Minimum 8 gallons in customer-supplied sump. 

Location: Below the HPTO, and allow for gravity drain from at least two 

1 1/2 NPTF drain ports. 

Breather: (optional) Can be integrated with fill cap. 

Breather Ports: When the sump has a breather, a 19.05 mm. (3/4”) port 

is used to connect a hose from the HPTO to the sump. Do 

not integrate with drain ports. 

Drain Ports: Use maximum possible diameter drain hoses (1 1/2 inch 

diameter) with least restrictive fittings. All three drain hoses 

must be used with SAE 40 viscosity oil to prevent overheating 

from entrapped oil. 

Suction: Use suitable suction screen to prevent pump damage. Use 

suitable suction hose to prevent cavitation. 

Baffles: Use baffles to allow return oil to settle away from suction 

port. 

Oil Scavenge Pump (See engineering drawing for additional specs.) 

If sump cannot be located below the HPTO, a customer supplied scavenge 

pump that is approximately two times the size of the charge pump must be 

used to adequately remove the oil from the pto housing. 

Oil Pump (See engineering drawing for additional specs.) 

Capacity: Oil flow of 8.5 GPM is required at 1000 rpm. Standard Twin 

Disc supplied pump supplies 0.0085 gal/rev. 

Rotation: The pump rotates in engine speed direction when mounted 

on the output side of the pump drive, or opposite engine speed 

direction when mounted on the input side of the pump drive. 

Oil Pressure 

See table 2. Oil temperature must be in the normal operating range. The 

range of values shown on the chart is based upon specific flow rates, 

temperatures and oil used. Contact Twin Disc engineering for guidance 

regarding modified parameters. 



Limits for HPTO with 0.0085 Gallons/Rev. pump attached to HPTO gear housing 

rpm 

700 

2100 

Range 

Clutch 

Brake 

Neutral 

Clutch 

Neutral 

Min. 

kPa 

(psi.) 


Table 2. Oil Pressure Specification 

Main Clutch Brake Lube Cooling 

Act. 

kPa 

(psi.) 

Max. 

kPa 

(psi.) 

Min. 

kPa 

(psi.) 

Act. 

kPa 

(psi.) 

Min. 

kPa 

(psi.) 

Act. 

kPa 

(psi.) 

Min. 

kPa 

(psi.) 

Act. 

kPa 

(psi.) 

Max. 

kPa 

(psi.) 

1650 1790 1650 0 276 414 

(240) (260) (240) (0) (40) (60) 

1650 1790 0 1650 276 414 

(240) (260) (0) (240) (40) (60) 

1650 1790 0 0 276 414 

(240) (260) (0) (0) (40) (60) 

1650 1790 1650 0 414 552 

(240) (260) (240) (0) (60) (80) 

1650 1790 0 0 414 552 

(240) (260) (0) (0) (60) (80) 

Cooling temperature range: Delvac 10W Oil at 29 o C. - 35 o C. (85 o F. - 95 o F.) or Mobilkote 501 at 32 o C. - 38 o C. (90 o F. - 100 o F.) 

Required: Clutch lube pressure = Brake lube pressure within 21 kPa (3 psi) 

Rear support is required for testing. 

Figure 1. Oil pressure pickup points 

Lube Pressure Port 

Brake Pressure Port 

Clutch Pressure Port 

Main Pressure Port 

Lube Pressure Port 

Temp 

o C. 

( o F.) 

23


24 

Fittings (See engineering drawing for additional specs.) 

Fittings must meet SAE 514, SAE J476, J518 standards. 

Hose Type (See engineering drawing for additional specs.) 


Hoses must meet SAE 517 specifications for 100R17 or similar type for 

hydraulic applications. 

Electronic Control Module 

Operating voltage range. 9 to 32 Volts DC 

Operating temperature range. -40 o C. (-40 o F.) to 85 o C. (185 o F.) 

Output Speed Sensor Air Gap 

Two turns out from touching the outer diameter of the gear. 

Input Speed Sensor Air Gap 

One and one half turns out from the outer diameter of the gear. 

Torque on input and output speed sensor lock nuts 

27 Nm. (20 lb.-ft.) 

Remote Mounted Electronic Control Cable 

See information contained in Installation section. 

Shim Tolerance for bearing carrier (65) in idler gear (58). 

Refer to the parts list and exploded view illustration. 

The designed shim tolerance is .1016 mm. loose to .0254 mm. tight 

(.004” loose to .001” tight). 



Twin Disc PTO Support Plate Specifications 

For Straddle-bearing type 

For In-Line type 

PTO 

Model 

Engine Bed 

Frame 

Figure 2. Support plate dimensions 

A 

Bore 

+.127/.025mm 

(+.005/+.001”) 

HPTO300S 238.15 mm 28.58 cm 16.21 cm ** 8 17.46 mm 19.05 mm 

9.376” 11.250” 6.38” ** 8 11/16” 3/4” 

HPTO600S 238.15 mm 28.58 cm 16.81 cm ** 8 17.46 mm 19.05 mm 

9.376” 11.250” 6.62” ** 8 11/16” 3/4” 

* Based upon an 8-hole bolt pattern without bolt holes in the 12 and 6 o’clock 

positions. 

** Angular offset of thru holes (D) must be calculated with respect to orientation of 

sheave housing. Holes are evenly spaced, i.e. 360/8 = angular spacing of thru 

holes. 


G 

Shim to 

within 

.12 cm. 

(.005”) 

13.49 mm. (17/32”) dia. 

thru holes 30 

Plate 

thickness = G 

0 apart on 

449.99 mm. (17.716”) 

dia. B.C. 

NOTE: One possible mounting method provides installation 

ease. Use angle iron to couple the support plate to the 

engine frame. 

B 

Bolt 

Circle 

A 

B 

C 

Radius 

C* D 

Width 

43.18 cm. (17.0”) min. 

D 

Degree 

E 

Hole 

Quantity 

F 

Hole 

Diameter 

E (qty.) 

F (dia.) 

41.91 cm. (16.500”) R 

NOTE: PTO deflection due to loads imposed by the application 

should not exceed .25 mm (.010”). Deflection should 

be measured at the support plate pilot with the dial 

indicator base mounted on a rigid part of the engine. 

G 

Recommended 

Thickness 

25


Torque Values for U.S. Fasteners 

26 

Table 3. - Coarse Thread Capscrews, Bolts and Nuts 


Thread 

SAE Grade 5 SAE Grade 8 

Diameter Nm lb-ft Nm lb-ft 

1/4 8 - 11 6 - 8 10 - 12 14 - 16 

5/16 18 - 23 13 - 17 20 -24 27 - 32 

3/8 34 - 39 25 - 29 35 - 41 48 - 55 

7/16 51 - 58 37 - 43 55 - 65 75 - 88 

1/2 81 - 95 60 - 70 83 - 97 113 - 131 

9/16 111 - 132 82 - 98 120 - 140 163 - 190 

5/8 163 - 190 120 - 140 165 - 195 224 - 264 

3/4 278 - 332 205 - 245 295 - 345 400 - 467 

7/8 448 - 528 330 - 390 470 - 550 638 - 745 

1 495 - 595 671 - 806 715 - 845 970 - 1145 

1 1/8 615 - 745 834 - 1010 1015 - 1185 1377 - 1606 

1 1/4 850 - 1000 1163 - 1355 1375 - 1625 1865 - 2203 



Table 4. - Metric Coarse Thread Capscrews, Bolts and Nuts 

Thread Property Class 8.8 Property Class 10.9 Property Class 12.9 

Size lb-ft Nm lb-ft Nm lb-ft Nm 

M6 6.5 - 7.5 9 - 10 9 - 10 12 - 14 10 - 12 14 - 16 

M8 16 - 18 21 - 25 23 - 26 31 - 35 25 - 29 34 - 40 

M10 32 - 36 43 - 49 44 - 51 60 - 68 51 - 59 70 - 80 

M12 55 - 63 74 - 86 77 - 88 104 - 120 89 - 103 121 - 139 

M16 132 - 151 179 - 205 189 - 217 256 - 294 219 - 253 298 - 342 

M20 257 - 295 348 - 400 364 - 418 493 - 567 429 - 493 581 - 669 

M24 445 - 511 603 - 693 626 - 720 848 - 976 737 - 848 1000 - 1150 

M30 714 - 820 987 - 1113 1235 - 1421 1674 - 1926 1475 - 1697 2000 - 2301 

Table 5. - Tapered Pipe Plugs (with thread lubricant) 

In cast iron or steel In aluminum 

NPTF Size (in) Nm (+ or - 5%) lb-ft (+ or - 5%) Nm (+ or - 5%) lb-ft (+ or - 5%) 

1/16-27 11.5 8.5 7.5 5.5 

1/8-27 14 10.5 9 6.5 

1/4-18 34 25 21.5 16 

3/8-18 36.5 27 23 17 

1/2-14 68 50 40.5 30 

3/4-14 73 54 46 34 

1 - 11 1/2 108 80 68 50 

1 1/4 - 11 1/2 115 85 75 55 

1 1/2 - 11 1/2 115 85 75 55 


27


28 


Table 6. - Straight Threaded Tube Fittings, Hose Fittings, and O-Rings 

Nominal 

Thread 

Diameter 

Nm 

(+ or - 5%) 

lb-ft 

(+ or - 5%) 

5/16 5 3.5 

3/8 11.5 8.5 

7/16 16 12 

1/2 20 15 

9/16 24.5 18 

5/8 24.5 18 

11/16 34 25 

3/4 40.5 30 

7/8 54 40 

1 1/16 75 55 

1 3/16 88 65 

1 1/4 88 65 

1 5/16 108 80 

1 3/8 108 80 

1 5/8 135 100 

1 7/8 162 120 

2 1/2 312 230 

Nominal 

Thread 

Diameter 

Nm 

(+ or - 5%) 

lb-ft 

(+ or - 5%) 

M10X1.0 26 19 

M12X1.5 37 27 

M14X1.5 47 35 

M16X1.5 58 43 

M18X1.5 74 55 

M22X1.5 105 77 

M27X2.0 179 132 

IN IRON 

M27X2.0 

IN ALUM. 

85 63 

M33X2.0 326 240 

M42X2.0 347 256 

M48X2.0 441 325 



Wear Limits 

Item 

Maximum Diameter 

mm. inches 

A Bearing Bore 150.0251 5.9065 

B Bearing Bore 

Hsg. #1020659 215.0466 8.4664 

Hsg. #1020659b 215.0466 8.4664 

Hsg. #1020659c 215.9762 8.5030 

C Bearing Bore 

Hsg. #1019124 160.0225 6.3001 

Hsg. #A7576 170.0378 6.6944 

Hsg. #1020654 215.0466 8.4664 

Front Housing 

A 

Bearing Bore 

Model I Bearing Carrier 


The following list maximum diameters sizes for bearing bores and minimum 

diameters for bearing journals and seal contact surfaces. 


Table 7. Bearing Bores and Bearing Journals 

D 

Bearing Bore 

Clutch Housing 

B 

Bearing Bore 

E 

Bearing Bore 

Maximum Diameter 

Item 

mm. inches 

D Bearing Bore 215.9762 8.5030 

E Bearing Bore 125.0112 4.9217 

H Bearing Bore 

SAE “A” size 90.0227 3.5442 

SAE “B” size 90.2767 3.5542 

SAE “C” size 90.2767 3.5542 

Minimum Diameter 

Item 

mm. inches 

F Bearing Journal 100.0023 3.9371 

G Bearing Journal 50.0024 1.9686 

Gear & Drive 

Ring Asy. 

F 

Bearing 

Journal 

Belt Sheave 

Housing 

C 

Bearing Bore 

SAE Mounting 

Plate 

H 

Bearing Bore 

G 

Bearing 

Journal 

Driven Gear 

29


Bearing Journal Seal Contact Surface 

M 

N 

Shaft Minimum Diameter Minimum Diameter 

Part Number mm. inches mm. inches 

30 

Table 8. Bearing Journals and Seal Contact Surfaces on Shafts 

Seal Contact Surface 

P 


mm. inches 


Seal Contact Surface 

Q 


mm. inches 

#1020660b 70.1010 2.7563 107.7341 4.2415 101.4095 3.9925 95.0595 3.7425 

#1020678c 70.1010 2.7563 107.7341 4.2415 101.4095 3.9925 95.0595 3.7425 

#1020678d 70.1010 2.7563 107.7341 4.2415 101.4095 3.9925 95.0595 3.7425 

#1020678e 70.1010 2.7563 107.7341 4.2415 101.4095 3.9925 95.0595 3.7425 

#1020678f 70.1010 2.7563 107.7341 4.2415 101.4095 3.9925 95.0595 3.7425 

#1020678g 70.1010 2.7563 107.7341 4.2415 101.4095 3.9925 95.0595 3.7425 

N 

Seal Contact 

Surface 

Shaft 

Typical 

Model 300S & 600S 

Shaft 

Bearing Journal Seal Contact Surface Bearing Journal 

J 

K 

L 

Shaft Minimum Diameter Minimum Diameter Minimum Diameter 

Part Number mm. inches mm. inches mm. inches 

#1020660b 120.523 4.7450 130.0988 5.1220 120.0581 4.7267 

#1020678c 71.374 2.8100 130.0988 5.1220 120.0581 4.7267 

#1020678d 80.010 3.1500 130.0988 5.1220 120.0581 4.7267 

#1020678e 80.010 3.1500 130.0988 5.1220 120.0581 4.7267 

#1020678f n/a n/a n/a n/a 139.7406 5.5016 

#1020678g n/a n/a n/a n/a 139.7406 5.5016 

P 

Seal Contact 

Surface 

J 

Bearing Journal 

Q 

Seal Contact 

Surface 

K 

Seal Contact 

Surface 

L 

Bearing 

Journal 

M 

Bearing Journal 

Shaft 

Typical 

Model 300I & 600I 

Shaft 


Twin Disc, Incorporated Operation 

General 

Power Take-off Service Manual 

Operation 

A Flexible Torsional Input Coupling is bolted to the engine flywheel. The 

coupling’s internal spline meshes with an external spline on the drive gear. 

External teeth on a series of Clutch Friction Plates are in constant contact with 

internal teeth of the drive gear. These and related components comprise the 

basic input drive portion of the Power Take-off and are in rotation at engine 

speed whenever the engine is running. 

A series of internally splined Steel Clutch Plates are located between the Clutch 

Friction Plates. Their internal teeth mesh with external teeth on the Clutch Hub, 

which is, in turn, splined to the Clutch Shaft. These and related components 

comprise the basic output portion of the Power Take-off and are in rotation 

when partial or full clutch is engagement occurs (see below). 

The Back Plate is contained within the Clutch Piston forming an operating cavity 

into which high-pressure oil is directed by the GP Control Valve. A Piston Carrier, 

located inside the Clutch Piston separates the clutch-engagement side from 

the brake-engagement side of the cavity. 

Multiple accessory drives (on some models) are in rotation whenever the engine 

is running. Their output speed is always the same as engine speed. 

The General Purpose (GP) Control Valve with its electronic interface is used to 

obtain brake engagement, coast, and clutch engagement in this hydraulic power 

take off. When these positions are selected by the operator, and the proper 

conditions exist, the control valve directs high-pressure oil through internal 

passages to instantaneously and smoothly apply the brake, or to engage the 

hydraulic clutch. The pressure-rate of rise, controlled by the electronic module, 

provides a rapid, smooth, clutch engagement. 

On initial startup and service, closely monitor the pressure while starting 

the engine to ensure that the pump primes. Do not run the engine for 

longer than 10 seconds if measurable main pressure does not register. 

31

Operation 

32 


General Overview of GP Control Valve with Electronic Interface 

The General Purpose (GP) control valve is a hydraulic valve assembly designed 

for use with this power take-off, that includes a remotely mounted electronic 

interface control module. The valve assembly contains electrical-currentcontrolled 

proportional cartridges. 

Power Take-off Service Manual


GP Control Valve Hydraulic Portion 


The hydraulic portion of the GP Control Valve is made up of two blocks, a lower 

main regulator valve body, and an upper valve body. These valve bodies contain 

two electrically-actuated proportional valves, and a hydraulic pressure regulator 

(consisting of a pilot relief valve assembly and a main spool valve assembly). 

Separate identical proportional valves are used for the brake and the clutch 

engagement. When the power take-off clutch is selected to be engaged, the 

control valve directs high-pressure oil through internal passages to operate the 

clutch. When brake engagement is selected, the brake control valve directs 

high-pressure oil to operate the brake. (The clutch and brake are never engaged 

at the same time.) The pressure-rate of rise (profile) is controlled electronically 

by the GP Control Valve electronic interface to provide a rapid, smooth, oil 

pressure increase in the clutch or brake hydraulic passages during engagement. 

The proportional valve coils are low resistance devices that are electrical 

current driven. The use of an uncontrolled power source may supply 

too much current and damage the proportional valve. 

Note: Installations with this valve must include an oil filter 

with the proper filtering characteristics. This valve 

requires a filtration level of 16 micron at an efficiency 

of 98% (beta ratio = 75) or better. Besides the valve's 

requirement on filtration, the filter must meet the 

requirements of the power take-off (operating 

pressure, flow, etc.) 

33

Operation 

34 

Figure 3. Hydraulic Schematic (GP control valve) 





Figure 4. Top Hydraulic Valve Body Assembly 

Pressure Regulator 

Figure 5. Main Regulator Hydraulic Valve Assembly 

Valve section 

used with valve 

assembly 1020729 

Valve section 

used with valve 

assembly 1021658 

35

Operation 

Hydraulic System with GP Control Valve 

36 


The oil pump draws oil from the oil sump and discharges it to the heat exchanger, 

and on through the oil filter. Filtered oil enters the control valve through the inlet 

port. The incoming oil is supplied to the main pressure regulating relief pilot 

valve and the main regulating valve cartridge, satisfying the main pressure 

requirements of the HPTO and cascading all remaining oil flow into the 

lubrication circuit. Oil not used for clutch or brake engagement flows past the 

regulator piston to become lubrication oil. Lubrication oil flows through the 

lubrication oil circuit in the pto to lubricate and cool the clutches and bearings. 

Main pressure is supplied to the inlet of each proportional valve. Prior to 

engagement, the areas behind the clutch piston and brake piston are open to 

sump when the solenoids are not energized. The clutch and brake are 

hydraulically disengaged, but springs in the clutch unit cause the brake to be 

mechanically engaged. (The clutch is disengaged at that time.) 

When the clutch is commanded to engage, the proportional valve directs main 

pressure to a passageway in the clutch shaft. The oil is directed between the 

carrier and the apply piston. The apply pistons for the power take off clutch and 

the brake are connected so that when the clutch is hydraulically applied, the 

apply piston for the brake is pulled away from the clutch plate(s), preventing 

brake engagement. The clutch engagement, including the rate-of-rise, is 

controlled electronically utilizing a closed loop logic that is programmed into 

the HPTO Control Module. 

Clutch release occurs when the proportional valve is de-energized. (At that 

time, the springs in the clutch unit will mechanically engage the brake. 

The electronic interface portion of the control valve allows only one proportional 

valve to be energized at a time, thus, apply oil can only be supplied to either the 

brake or the clutch at one time, and the oil from the disengaged unit is vented to 

sump (atmospheric pressure). The pto clutch release springs move the clutch’s 

apply piston to the disengaged position minimizing clutch plate drag. 

See the Hydraulic Piping Diagram on the following page. 

Note: The breather (108) that is located on the top of the 

pump drive tower can be moved to the sump, 

provided that a line is connected from the vent 

location on the pump tower to the sump, and the 

sump breather is located in a baffled “quiet” area 

where the oil flow path does not affect the sump area 

by the breather. 



Pump Outlet 

Port 

Pump Inlet 

Port 

1 1/4”Hose 

1 1/2-11 1/2 NPTF 

Thread 

Drain Port 


1 1/2”Hose 

1”Hose 

Pump 

Pump Inlet Port 

Valve Inlet Port 

Control Valve 

Assembly 

Figure 6. Hydraulic Piping Diagram 

Breather 

1”Hose 

3/4”Hose 


1 1/2-11 1/2 NPTF 

Thread 

1 1/2”Hose 

1 1/2-11 1/2 NPTF 

Thread 

Pump Outlet Port 

37

Operation 

38 

GP Control Valve Electronic Control Interface (Profile Module) 


The electronic portion of the GP Control Valve must be remotely mounted from 

the hydraulic portion of the GP Control Valve, because of the ambient 

temperature in most applications. 

If the ambient temperature of this mounting location exceeds 82 o C. 

(180 o F.), the Electronic Control Interface must be relocated to a cooler 

area. See Remote Mounted Electronic Control Cable in the Installation 

Section of this manual 

This module contains the electronic circuitry to control the proportional cartridges 

that are used to engage the clutch and brake, based on the commands from 

the operator, and the programmed logic. Clutch apply pressure rate of rise 

(profile) is factory set with the use of internal circuitry. Closed loop logic is used 

for all clutch engagements. There are no user adjustments on the HPTO Profile 

Module. All electrical wiring for the Hydraulic Power Take Off system controls 

are routed through this interface module. The machine’s battery power (12 vdc 

or 24 vdc) is supplied to the electronic interface only, and never directly to the 

hydraulic proportional valves. Two red led lights are used to identify the 

proportional cartridge valve that is energized, and a green led is used to identify 

when power is provided to the electronic module. Flashing lights are used in 

troubleshooting. Engine speed and clutch output speed sensors are required 

for the control logic. The following figure shows the Electronic HPTO Module. 

Do not connect valve coils directly to battery power supply voltage. 

Use an approved Twin Disc Control System. 

Figure 7. Electronic HPTO Module 



Clutch Engagement Logic (Closed Loop) 

Brake Engagement 


Any time that the PTO Output Speed is below a preset speed, and the Power 

Take Off Clutch is not commanded to be on, the Brake Valve Coil will be 

commanded on by a pre-programmed profile. When the clutch is engaged, 

the brake will be commanded to be off. Also, if the PTO Output Speed increases 

at any time a small amount above this preset speed, the Brake Valve Coil will 

be commanded off. 

Power Take Off Clutch Engagement 

Any time that the customer supplied PTO Engage Switch is closed, indicating 

that the operator wishes to engage the Power Take Off, the Control Module 

commands the brake to be off and begins two simultaneous logic processes. 

These are a Clutch Engagement process, and a Clutch Lockup Check process. 

Input Speed and Output Speed are monitored continuously. The following briefly 

describes the steps in the processes. 

The engine must be below a preset speed before any clutch engagement will 

be commanded. If the engine speed is proper, the clutch is engaged at a 

preset level, while engine speed and output speeds are monitored. The clutch 

pressure will be increased as fast as possible without reducing the engine 

speed below a preset speed. If no output speed is detected, the PTO clutch 

will be disengaged and reapplied. If no output speed is detected after four 

attempts, the warning relay will be closed, and no further engagements 

attempted for five minutes, allowing the clutch components to cool sufficiently. 

Do not shut off the power to bypass the five minute cool down period. 

Mechanical damage can occur if the clutch is not allowed to cool after 

each engagement. After five minutes, turn off the engine and determine 

why the output did not rotate. 

After five minutes, another clutch engagement can be attempted. The 

PTO Engagement Switch must be turned off to reset the warning relay. 

If an input speed sensor failure is detected, engagements of the PTO Valve 

Coil will not be allowed. 

If an output speed sensor failure is detected, engagements of the Brake Valve 

Coil will not be allowed. 

39

Operation 

40 



Twin Disc, Incorporated Installation 

Identifying the Twin Disc Power Take-off Model 

Power Take-Off Service Manual 

Installation 

The nameplate identifies the model, bill of material (BOM) and the serial number 

of the unit. These numbers are necessary to identify the correct parts for your 

transmission. 

41

Installation 

Identifying the SAE Housing Size 

42 

SAE 

Housing 

Size 

B 

A 

Figure 8. Basic dimensions for SAE housings 

Table 9. SAE Housing Identification 


A 

B 

C 

D 

Housing Housing Bolt Circle Bolt Holes 

Pilot Diameter 

mm. inches 

Flange O.D. 

mm. inches 

Diameter 

mm. inches 

Qty. 

Dia. 

mm. inches 

00 787.40 31.000 876.3 34.50 850.90 33.500 16 13.49 .531 

0 647.70 25.500 711.2 28.00 678.18 26.750 16 13.89 .547 

1 511.18 20.125 552.5 21.75 530.23 20.875 12 12.29 .484 

D 

C 

Power Take-Off Service Manual


Prior to Installation 


The Twin Disc Hydraulic Power Take Off mounts directly onto the flywheel 

of the engine. Flywheel-to-Power take off interference is possible due 

to mismatch of components or other reasons. Therefore, engine 

crankshaft endplay as well as flywheel alignment checks must be made 

before the Hydraulic Power Take Off is installed. 

After installation of the Hydraulic Power Take Off, the crankshaft endplay should 

be measured again. The endplay at the second measurement should be the 

same as the first. A difference in these two endplay measurements could be 

an indication of interference. Consequently, the Hydraulic Power Take Off should 

be removed and the source of interference found and corrected. 

Twin Disc will not be responsible for system damage caused by engine to Twin 

Disc Hydraulic Power Take Off interference regardless of the cause of 

interference. This engine crankshaft endplay check is considered mandatory. 

The power take off housing flange and pilot, the engine flywheel and the flywheel 

housing must be checked for trueness. Clean the engine flywheel and flywheel 

housing mounting surfaces thoroughly before any measurements are made. 

Filtration prior to start-up (new or rebuilt unit) 

1) Proper cleaning of hydraulic hoses prior to installing them on the HPTO. 

2) Insure cooler has been flushed and is indeed clean. 

3) Always install a filter at the inlet of the valve body in case residual debris 

was missed in the cooler after cleaning. 

4) At first start-up with new or rebuilt HPTO, check main and lube pressure 

to ensure pump has primed and producing oil pressure. 

43

Installation 

Preliminary Checks 

44 

Refer to Identifying the SAE Housing size in table 9. 


Note: All measurements must be taken with the engine or 

motor mounted on its supports after the flywheel and 

housing have been thoroughly cleaned. 

1. Measure and record the engine crankshaft or motor shaft endplay using 

a dial indicator. Record this value, as it will be used later._______ 

2. Bolt the indicator to the flywheel so the indicator is perpendicular to the 

flywheel housing face and the indicator stem rides on the flywheel housing 

face. See Figure 9. 

Figure 9. Checking Flywheel Housing Face 

3. Rotate the shaft through on entire revolution and note the runout. The 

total indicator reading (T.I.R.) must not exceed: 

SAE #0 Housing .41 mm. (.016”). 

SAE #1 Housing .30 mm. (.012”). 

Note: The flywheel and crankshaft of the engine must be 

held against either the front or rear of the crankshaft 

thrust bearing while the total indicator sweep (T.I.R.) 

is being made. 




4. Readjust the indicator so the stem rides on the pilot bore of the flywheel 

housing face. See Figure 10. 

Figure 10. Checking Flywheel Housing Bore 

5. Rotate the shaft through one entire revolution and note the runout. The 

total indicator reading (T.I.R.) should not exceed: 

SAE #0 Housing .41 mm. (.016”). 

SAE #1 Housing .30 mm. (.012”). 

6. Remove the indicator base from the flywheel and bolt it to the flywheel 

housing face. Position the indicator stem so that it rides where the drive 

ring will set on the flywheel face. See Figure 11. 

Figure 11. Checking Driving Ring Surface of Flywheel 

7. Rotate the shaft through one entire revolution and note the face runout of 

the flywheel. The total indicator reading (T.I.R.) must not exceed .01mm. 

(.0005”) per 25.4 mm. (per inch) of flywheel diameter. 

Note: The flywheel and crankshaft of the engine must be 

held against either the front or rear of the crankshaft 

thrust bearing while the total indicator sweep (T.I.R.) 

is being made. 

45

Installation 

46 


8. Readjust the indicator stem so it rides on the torsional input coupling 

pilot bore of the flywheel. See Figure 12. 

Figure 12. Checking Torsional Input Coupling Pilot Bore of Flywheel 

9. Rotate the shaft through one entire revolution and note the torsional input 

coupling bore eccentricity. The total indicator reading (T.I.R.) must not 

exceed .13 mm. (.005”). 



Torsional Input Coupling Installation 


Refer to the cleaning and inspection section of this manual before proceeding. 

1. Clean the flywheel and the input coupling face and outside pilot diameter 

of any dirt or debris as necessary. 

2. Use crocus cloth or emery cloth to remove any surface imperfections 

such as nicks, burrs, and sharp edges on the O.D. or the surface that 

will be mounted against the flywheel face. 

3. Use crocus cloth or emery cloth to remove any surface imperfections 

such as nicks, burrs, and sharp edges in the I.D. of the flywheel pilot 

bore or on the face that will be in contact with the input coupling. 

4. Position the input coupling against the flywheel, piloted in the mounting 

bore, and secure with eight hex-head capscrews. Torque the capscrews 

to the proper specifications given in Torque Values for U.S. Fasteners 

in the Description and Specifications section of this manual. 

Torsional Input Coupling attachment screws must be grade 8. Do not 

use substitutes. 

Be sure the internal retaining ring is properly installed inside the 

torsional input coupling hub. See Engineering Drawings section of this 

manual for correct ring location. 

47

Installation 

48 


Assembly Instructions for CENTAFLEX - R on Flange Mounted 

transmission. Information Taken from CENTA Drawing 26-60062-91-3. 

1. Bolt flywheel flange onto flywheel and tighten bolts as follows. 

Flywheel 

Figure 13. Assemble Flywheel Flange to Flywheel 

Table 10. Centa Tightening Torque Chart 

Thread Property Class 8.8 

Size Nm ft.-lbs. 

M10 50 37 

M12 85 63 

M16 215 159 

Mounting Bolt 

Flywheel Flange portion of 

the Torsional Input Coupling 

Tightening torque is for slightly oiled bolts, tolerance is + or - 5%. 

Securing of the bolts by adhesives (e.g. Loctite) is possible. 




2. Place rubber rollers in the deepest section of the cam in the output hub. 

Normally they stick there by friction. 

Figure 14. Insert Rollers and Note Alignment 

3. In case they do not stick, place a tape or a cord with a slip knot around 

all rollers close to the gear side. Leave the end of the tape or cord long 

enough so that it extends outside the flange. Turn the two coupling halves 

so that the arrows of both halves are opposite one another. See Figure 

14 (View X). 

Flywheel 

Figure 15. Coupling into Flywheel Flange 

Flywheel Flange portion of 

the Torsional Input Coupling 

Tape or Cord 

Rollers 

Internal portion of the 

Torsional Input 

Coupling 

49

Installation 

50 


4. Then push the output side of the coupling with the hub into the outer 

flange. If necessary apply lubricant on the outer flange. Suitable 

lubricants are soap water, detergents, etc. DO NOT USE OIL OR 

GREASE. If tape or a cord was used, push the coupling only half way 

together and remove the tape or cord. Then complete the installation. 

Figure 16. Assemble part way and remove the tape or cord. 

Figure 17. Final Assembly 

Remove 

Tape or Cord 



HPTO Installation to Engine 


Refer to the cleaning and inspection section of this manual before proceeding. 

When mounting the engine and Hydraulic Power Take Off in the machine, 

the six mounting bolts on each side of the mounting pads of the In-Line 

power take off must be used. The power take off mounting brackets 

should not be used to support the engine. A support plate must be 

used to support the output end of the Straddle Bearing Units. Failure 

to follow this guideline may result in damage to the power take off or 

the engine flywheel housing. 

See Engineering Drawings for installation dimensions and the locations of the 

required connections for power take off installation. 

HP300I HP300S HP600I HP600S 

The connections include the following: 

� Output shaft connection 

� Electrical connection for Control Module 

� Oil connection to the oil pump and heat exchanger 

� Oil connection from the heat exchanger to the oil filter 

� Speed pickups and pressure gauges 

1. Clean the PTO housing flange, flywheel housing flange of any debris. 

2. Make sure the housing flange and flywheel housing flange are free of 

surface imperfections such as nicks, burrs, and sharp edges. Remove 

them using fine emery cloth or crocus cloth. 

3. Install a minimum of 3 guide studs in the flywheel housing, located 

approximately 120 o apart. Using a suitable hoist, position the PTO on 

the guide studs and slide it against the flywheel housing, carefully aligning 

the teeth of the drive gear (12) with the internal teeth of the coupling (1). 

Do not force the pto unit onto the engine. If any resistance is noted, 

51

Installation 

52 

identify and correct all sources of interference. 


4. Secure the PTO housing to the flywheel housing with 12 hex-head 

capscrews (SAE #1 housing) or 16 capscrews (SAE #0 housing) . 

Torque the capscrews to the proper specifications given in Torque 

Values for U.S. Fasteners in the Description and Specifications 

section of this manual. 

Note: PTO housing to flywheel housing attachment screws 

must be grade 5 or better. 

5. Rap the end of the output shaft with a soft hammer to remove any preload 

on the main bearings and/or pilot bearing. 

Note: This step must not be omitted. Bearing failure may 

result. 

6. Measure the crankshaft endplay again. The measurement must be the 

same value as recorded from step 1 under Preliminary Checks. Locate 

and correct the source of preload if the endplay is not the same value. 

Engine and/or PTO failure will result from any excessive preload on 

components. 

7. Install the drive sheave, u-joint flange or other driven components as the 

application requires. 

HP300S and HP600S only: (Models 300I & 600I skip to step 8.) 

Note: Straddle bearing units only - refer to V-belt installation in 

the maintenance section and the Engineering Drawings 

towards the back of this manual. (Proceed at step 8.) 

HP300S, HP600S, HP300I and HP600I 

8. A PTO support plate mounted at the output bearing retainer must be 

used. Install the support plate. Refer to Support Plate Specifications 

in the Description and Specifications section and the Engineering 

Drawings towards the back of this manual. 

9. Measure and adjust for proper deflection and alignment. (See 

instructions near back of this section.) 

10. Attach hoses, hose fittings and other plumbing circuit components 

including the sump, oil filter and heat exchanger. (See plumbing 

illustrations near back of this section.) 




11. Attach the speed pickup(s) and pressure gauge(s). (See details 

contained in drawings in the Engineering Drawings section of this 

manual.) 

12. Mount the Electronic Control Module. 

The Electronic Control Module must be remotely mounted from the 

Hydraulic Power Take Off unit because of the possible temperatures 

reached at the power take off. See Figure 18 . 

Figure 18. Electronic Control Module 

53

Installation 

54 

13. Attach all electrical connections for the Control Module. 

Figure19. Wiring Schematic 





14. Attach the optional cables for remotely locating the control module are 

listed in the table 11. 

Length 

Figure 20. Cable for remote control operation 

Electrical Controls: All electrical wires and connectors must be 

adequately supported to prevent rubbing, chafing, or distress from 

relative movement. All electrical connections must be tight and free 

from any corrosion. See Figure 18 for the wiring connector. 

Part 

Length 

Number millimeters inches 

1021351A 1500 59 

1021351B 1800 71 

1021351C 2100 83 

1021351D 2400 94 

1021351E 2700 106 

1021351F 3000 118 

1021351G 3300 130 

1021351H 3600 142 

1021351J 3900 154 

1021351K 4200 165 

1021351L 4500 177 

1021351M 4800 189 

1021351N 5100 201 

1021351P 5400 213 

1021351Q 5700 224 

Table 11. Cable Lengths 

Part 

Number 

Length 

millimeters inches 

1021351R 6000 236 

1021351S 6300 248 

1021351T 6600 260 

1021351U 6900 272 

1021351V 7200 283 

1021351W 7500 295 

1021351X 7800 307 

1021351Y 8400 331 

1021351Z 9000 354 

1021351AA 9600 378 

1021351AB 10200 402 

1021351AC 10800 425 

1021351AD 11400 449 

1021351AE 12000 472 

1021351AF 12600 496 

55

Installation 

Final Checks 

56 


Before starting the engine, be sure the sump is properly filled with oil and the 

rear main bearing is properly greased. See Description and Specifications 

and Maintenance sections for the proper oil specification and filling procedure. 

Monitor the pressure while starting the engine to ensure that the pump 

primes. Do not run the engine for longer than 10 seconds if the pump 

does not prime, resulting in measurable main pressure. 

Check and Adjust Main Pressure (as needed) 

It is recommended that following the servicing of the valve assembly a procedure 

be followed to ensure the flushing of oil through the valve assembly, followed by 

adjustment of the main pressure. 

1. Install a main pressure gauge into the port on top of the Top Valve body. 

Top View 

Pilot Relief Valve 

Assembly 

Side View 

Figure 21. Main Pressure Port in Valve Body 

Main Pressure 

Port 


Valve assembly 

1020729 is 

illustrated. 

2. Remove protective cover cap located at the end of the pilot relief valve 

assembly. This will expose a 1/4" hex head adjustment screw. Loosen 

the jam nut on the stem. 




Cap 

Used with valve 

assembly 

1021658 

Jam Nut 

Used with valve 

assembly 

1020729 

Figure 22. Pilot Relief Valve Assembly/Pressure Regulator 

The Hydraulic Power Take-Off must be in the disengaged position before 

the engine is started. 

3. Turn this adjustment screw counterclockwise until it reaches a positive 

stop. This allows the engine to be started and flush any debris past the 

relief valve. 

4. Start engine with the HPTO control in set in the disengaged position. 

Main pressure should be approximately 689 kPa (100 psi.) or less. Allow 

the fluid to flush the valve for approximately 1 minute. 

Monitor the pressure while starting the engine to ensure that the pump 

primes. Do not run the engine for longer than 10 seconds if measurable 

main pressure does not register. 

5. Turn the 1/4" hex head adjustment screw clockwise to achieve the main 

pressure setting. A helpful practice is to turn the screw approximately 

35 kPa (approximately 5 psi.) beyond the desired setting and then adjust 

for the target pressure. This aids in reducing variance in pressure setting 

due to torsional wind-up of the internal pressure spring. 

Note: If main pressure is to be set with cold oil, adjust the 

main pressure to approximately 35 - 70 kPa (5 - 10 

psi.) higher than the desired hot oil value. 

6. Tighten the jam nut to a torque of 20 Nm. (15 ft.-lb.), install the protective 

cap, and torque it to14 Nm. (10 ft.-lb.) 

57

Installation 

58 

Check Clutch Operation and Pressures 


7. After the engine and Hydraulic Power Take-Off are warmed up, check 

oil pressures in accord with the pressures shown in the Oil Pressure 

Specification table in the Description and Installation section of this 

manual. 

Note: Read and become completely familiar with the Power 

Take-Off Clutch Engagement explanation in the 

Operation Section of this manual. 

8. Engage the clutch. Automatic brake disengagement should allow shaft 

rotation to reach full speed. 

Note: Read and become completely familiar with the Brake 

Engagement explanation in the Operation Section 

of this manual. 

9. Disengage the clutch. Check to be sure shaft rotation slows to a stop 

when the clutch is disengaged. Automatic brake engagement will 

eventually stop shaft rotation when the clutch is disengaged. 



Plumbing - HP300I, HP300S, HP600I, HP600S 

Pump Outlet 

Port 

Pump Inlet 

Port 

1 1/4”Hose 

1 1/2-11 1/2 NPTF 

Thread 

Drain Ports 


1 1/2”Hose 

1”Hose 

Pump 

Pump Inlet Port 


Control Valve 

Assembly 

Breather 

1”Hose 

3/4”Hose 


1 1/2-11 1/2 NPTF 

Thread 

1 1/2”Hose 

1 1/2-11 1/2 NPTF 

Thread 

Pump Outlet Port 

59

Installation 

60 



Twin Disc, Incorporated Maintenance 

Allowable Side Loads 


S 

Maintenance 

Figure 22. Allowable Side Pull and Formula to Determine Applied Load 

Formula values for Figure 22. 

� L = actual applied load (Lbs.) 

� N = shaft speed (RPM) 

CENTERLINE 

OF SIDE 

LOAD 

� D = pitch diameter (in.) at sheave, etc. 

� F = load factor 

− 1.0 for chain or gear drive − 2.5 for all V belts 

− 1.5 for timing belts − 3.5 for flat belts 

� LF = 2.1 for reciprocating compressors and other severe shock drivers 

and 1.8 for large inertia type drive (crushers, chippers, planers) 

A support plate must be attached at the rear of the PTO. 

Note: HP300I and HP600I Hydraulic Power Take-offs are 

recommended for in-line, not side-loaded, 

applications. 

L= 

126,000 x H.P. 

N x D 

x F x LF 

61

Maintenance 

62 

Allowable Side Loads HP300S 

Maximum Load, Lbs. 

15000 

14000 

13000 

12000 

11000 

10000 

9000 

RPM 

1500 

1800 

2100 

2400 

Table 12 - HP300S Side Load Capacity Values 

N 

Lbs. 

N 

Lbs. 

N 

Lbs. 

N 

Lbs. 

Side Load Chart - HPTO 300S 

“S” Dimension 


127 (5.0) 152.4 (6.0) 177.8 (7.0) 203.2 (8.0) 228.6 (9.0) 254 (10.0) 

"X" Distance, mm. (inches) 

1500 RPM 1800 RPM 2100 RPM 2400 RPM 

127.0 mm. 152.4 mm. 177.8 mm. 203.2 mm. 228.6 mm. 254.0 mm. 

5.0 inches 6.0 inches 7.0 inches 8.0 inches 9.0 inches 10.0 inches 

47149 52931 60493 65385 56934 50485 

10600 11900 13600 14700 12800 11350 

44480 50040 56834 61827 54043 47816 

10000 11250 12800 13900 12150 10750 

42478 47816 54488 59158 51597 45814 

9550 10750 12250 13300 11600 10300 

40744 45814 52486 56934 48595 44035 

9160 10300 11800 12800 11150 9900 



Allowable Side Loads HP600S 

Maximum Load, Lbs. 

22000 

20000 

18000 

16000 

14000 

RPM 

1200 

1800 

2100 


N 

Lbs. 

N 

Lbs. 

N 

Lbs. 

Side Load Chart - HPTO 600S 

127.0 (5.0) 152.4 (6.0) 177.8 (7.0) 203.2 (8.0) 228.6 (9.0) 254.0 (10.0) 279.0 (11.0) 

"X" Distance, mm. (inches) 

"1200 RPM" 1800 RPM 2100 RPM 

Table 13 - HP600S Side Load Capacity Values 

“S” Dimension 

127.0 mm. 152.4 mm. 177.8 mm. 203.2 mm. 228.6 mm. 254.0 mm. 279.0 mm. 

5.0 inches 6.0 inches 7.0 inches 8.0 inches 9.0 inches 10.0 inches 11.0 inches 

79619 87181 96966 97856 90274 82510 74726 

17900 19600 21800 22000 20700 18560 16800 

70278 77396 56834 87626 82288 73837 66720 

15800 17400 19300 19700 18500 16600 15000 

67165 73837 54488 83622 78730 70723 64051 

15100 16600 18400 18800 17700 15900 14400 

63

Maintenance 

Lubrication 

64 


Refer to Engineering Drawings and figure 23 below for location of fittings. 

Grease Specifications (rear-straddle type - HP300S & HP600S) 

NLGI grades 0, 1, or 2 with allowable continuous use up to 135 o C. 

(275 o F.) are acceptable. Recommended greases include Mobilgrease 

XHP 222, Mobilgrease CM-S, Mobilux EP-2 or equivalent. 

Grease Specifications (rear-straddle type - HP300S & HP600S) 

Add 1cc every 10 hours of use. See figure 23 for location of grease fitting. 

Enlarged View 

(Typical) 

Side View (Typical) 

Lubrication Point 

Hydraulic PTO (Rear StraddleType) 

Figure 23. Location of lubrication points 

Lubricate the rear 

Main Bearing (grease) 

Rear View (Typical) 



Oil Specifications 

Oil System 


Note: The remaining portion of the HPTO Straddle-Bearing 

unit is oil-lubricated. HPTO In-Line units are oillubricated 

and require no grease lubrication. 

See specifications contained in Description and Specifications section. 

Oil Level 

The customer supplied sump oil level should be checked daily or every 10 

hours. A dipstick or sight glass is the preferred means of checking oil level. 

Oil and Filter Change Interval 

With a new unit, change the oil and filter element within the first 50 hours of 

operation. Change oil and filter element after each 1000 hours thereafter or 

more often if conditions warrant. The oil and filter should be changed every six 

months if less than 1000 hours has accumulated since the last oil change. 

For a repaired unit, check the filter element after eight hours of operation. If the 

filter is clean, install a new filter element and then change the oil and filter element 

after 1000 hours of service. If the filter is dirty, change the element and operate 

for another eight hours. Check the filter again. Continue this cycle until the filter 

is clean and then change the oil and filter after 1000 hours of service or more 

often if conditions warrant. 

Oil Suction Strainer 

Remove and clean the pump suction strainer at every oil change or sooner if 

necessary. The suction strainer is customer provided, and should be located 

in the suction line near the sump. 

65

Maintenance 

Torsional Coupling 

66 


1. Do not obstruct the flywheel housing vents preventing the free flow of air 

for cooling the coupling. The ambient temperature of the air around the 

coupling should be between -6 o C. (22 o F.) and 80 o C. (176 o F.). Assure 

baffles are installed properly so hot air is ported out of the housing. 

2. Visually inspect the element after the first 100 hours of operation and 

every 2000 hours thereafter, or every six months, whichever comes first. 

Torsional vibration, misalignment, degradation by contaminants (oil), 

heat, ultraviolet radiation, and excessive system torque can cause cracks 

or other signs of distress to appear on the surface of the rubber. The 

above-described items affect the life of the coupling element. 

When inspecting the flexible coupling, look for evidence or conditions 

identified in the following steps: 

A. Cracks in the surface of the rubber. May be caused by torsional 

vibrations, excessive misalignment or exposure to contaminants 

(heat, petroleum products, chemicals, ozone, ultraviolet radiation, 

etc.) excessive system torques. 

B. Deterioration of the rubber element, as evidenced by sponginess 

or by black carbon-like dust on rubber surface. May be caused 

by contaminants or excessive heat, either external or internal to 

the coupling. 

C. Cracked, bent or otherwise damaged flex plate or coupling plate. 

D. Bolt holes in flex plate or coupling plate are elongated oval 

shaped, not round. This could be caused by improperly 

assembled parts, loose parts, vibration or improperly torqued 

parts. 

E. Bolts/nuts—bent, worn or stripped threads. 

3. Inspect the hub, looking for the following: 

A. Damaged or worn splines. 

B. Cracked parts. 

4. Replace any defective parts including defective fasteners that are found. 



Overhaul Interval 


A complete overhaul of the unit should be made at the same time that 

the engine is overhauled. 

Periodic Visual Inspection 

1. Check the mountings for tightness or damage such as cracks. 

Tighten loose mountings and replace damaged parts. 

2. Check pressure and temperature gauge where applicable. 

3. Inspect the oil lines and heat exchanger for leaky connections, 

cracks, or other damage. Replace damaged lines. 

4. Periodically, inspect the drive line and the input and output shaft 

oil seals for leakage. Replace parts as required. 

67

Maintenance 

Deflection Alignment Adjustment 

68 


1. Proper alignment of an engine and the Hydraulic Power Take Off is 

critical, both during the initial installation and following the reinstallation 

after removal for servicing. The following steps may be taken to secure 

proper power take off alignment. 

2. When reinstalling a Hydraulic Power Take Off after a repair, or when 

installing a new Hydraulic Power Take Off to an engine already mounted 

in the bed rails, the flywheel housing should be checked for deflection 

using the following procedure: 

3. Install the mounting brackets on the side mounting pads of the Hydraulic 

Power Take Off. Install the driving ring on the engine flywheel. Bolt an 

indicator to the engine block and set the indicator stem on the engine 

flywheel housing 

Support plate 

Figure 24. Hydraulic Power Take Off Alignment (In-line version illustrated) 

4. Set the indicator gauge at zero (0). Lift the Hydraulic Power Take Off 

with a hoist, or other suitable means, and place the unit in position against 

the engine flywheel housing. Secure the flange of the Hydraulic Power 

Take Off housing to the engine flywheel housing. 




5. Use a feeler gauge between each mounting bracket and engine bed 

rail. Add shims between the brackets and bed rails to equal the feeler 

gauge readings. 

6. Carefully release the lifting force on the Power Take Off while observing 

the indicator. The indicator gauge must remain steady at the zero mark. 

Torque the mounting bracket to bed rail bolts to the proper rating. If the 

reading moves from zero, lift the Hydraulic Power Take Off and insert 

additional shims. 

7. Continue this procedure until the Hydraulic Power Take Off is completely 

at rest on the bed rails and the gauge maintains a steady zero reading. 

8. After obtaining the correct zero reading, indicating no distortion of the 

engine flywheel housing, secure the mounting brackets to the engine 

bed rails. 

Verify the PTO is properly lubricated prior to starting the engine. All 

bearings within the main unit are oil lubricated, supplied by the oil charge 

pump feeding the HPTO. Be sure to check oil pressures in accord with 

Table 2 in the Description and Specifications section of this manual. 

The rear main bearing of HP300S and HP600S (straddle bearing designs) 

are lubricated by grease and have a hydraulic (“zerk”) grease fitting. 

See Lubrication in the Maintenance section for more information. 

69

Maintenance 

Alignment - U-Joint-Type Installation 

70 

Refer to figure 25 on next page. 


To realize the longest possible life of the power take-off bearings, the best 

possible alignment must be maintained between the center line of the power 

take-off shaft and the center line of the driven unit shaft. 

1. It is extremely important that the forks of the drive shaft between the pto 

and the driven unit lie in the same plane. This will prevent severe 

vibrations from occuring in the drive shaft. 

2. The center lines of the pto shaft and the driven unit input shaft must be 

offset within the limits recommended by the u-joint manufacturer to 

prolong the life of the universal joint needle bearings. 

3. It is extremely important that the center lines of the pto shaft and driven 

unit input shaft be parallel. This will further prevent vibrations which cause 

premature pto bearing failure. 

4. Proper lubrication of the pto is important for satisfactory service. Refer 

to lubrication specifications in the Maintenance section. 

Align the centerlines of the pto shaft and the input shaft of the driven 

unit. (One possible method is described below.) 

5. To align the engine and gear head by this method, two accurate straight 

edges at least 91 cm. (36”) long and a tape measure are required. 

6. Place the straight edges horizontally along the face of the pto and gear 

head hubs. Measure distances A and B. These two distances should 

be equal within 3.17 mm. (.125”) at a point 45.7 cm. (18”) from the 

centerline of the shaft. Move the engine and/or driven unit to obtain this 

specification. 

7. Rotate the shafts so the straight edges are in a vertical position. Measure 

the distances C and D as was done for A and B in step 2. These two 

distances should be equal within 3.17 mm. (.125”) at a point 45.7 cm. 

(18”) from the centerline of the shaft. Move the engine and/or driven unit 

to obtain this specification. 



Engine 


PTO 

45.7cm 

(18”) 

45.7cm 

(18”) 

Figure 25. Alignment - U-Joint-Type Installation 

B 

Vertical Position 

Horizontal Position 

Fork 

D 

Driven 

Unit 

8. Secure the engine and driven unit. Recheck A and B, C and D as 

described in steps 5 through 7 above. All measurements must be within 

the specifications. If not, repeat steps 5 through 7 until specifications 

are met. 

C 

A 

Fork 

Parallel Centerlines 

71

Maintenance 

72 



Twin Disc, Incorporated Disassembly 

Power Take-off Removal From The Engine 


Disassembly 

Refer to the exploded view illustrations near the back of this manual. 

1. Disconnect all electrical and electronic connections. Remove all oil hoses 

and cap all open fittings to prevent oil from leaking out. Remove all 

attached parts from the output end of the power take-off. 

Models HP300S and HP600S: (Models HP300I and HP600I skip to step 

13.) 

2. Remove the support plate from the output end of the power take-off. 

3. Attach lifting equipment to the belt sheave housing (46) and take out the 

slack just enough to begin to support the weight of the housing. Do not 

apply too much force. 

Lifting devices and their capacity must be capable of supporting the 

weight of the power take-off and all attached devices and equipment. 

Suspend the pto with the lifting devices securely attached at 3 positions 

(minimum) so it remains with the main drive shaft in a horizontal position 

until it is safely lowered and resting on a secure bed. 

4. Remove the hex-head capscrews (53) securing the rear bearing retainer 

(50) to the belt sheave housing (46). Remove the rear bearing retainer 

with the grease fitting (49). 

Models HP300S only: (Model HP600S skip to step 9.) 

5. Remove the snapring (52) from the output shaft (12). 

6. Remove 12 hex head screws (47) securing the belt sheave housing 

(46) to the clutch housing (37). 

7. Separate the sheave housing from the clutch housing (37), slide it off 

the shaft and set it aside. The roller bearing (51) will be removed with 

the sheave housing. 

8. Remove the roller bearing (51) from the sheave housing. (Proceed to 

step 12.) 

73

Disassembly 

74 


Models HP600S only: 

9. Remove 12 hex head screws (47) securing the belt sheave housing 

(46) to the clutch housing (37). 

10. Separate the sheave housing from the clutch housing (37), slide it off 

the shaft and set it aside. The outer race of the spherical roller bearing 

(51) will be removed with the sheave housing. 

11. Remove the outer race (51) from the sheave housing. (Proceed to step 

12.) 

Note: The inner race of bearing (51) will be removed later, if it 

must be replaced. 

Models HP300S and HP600S 

12. Remove the belt sheave (customer component) and the output key (55). 

(Proceed to step 13.) 

All Models: 

13. Attach lifting equipment to the power take-off and take out the slack just 

enough to begin to support the weight of the pto. Do not apply too much 

force. 


weight of the power take-off and all attached devices and equipment. 

Suspend the pto with the lifting devices securely attached at 3 positions 

(minimum) so it remains with the main drive shaft in a horizontal position 

until it is safely lowered and resting on a secure bed. 

14. Remove all bolts, brackets and devices supporting the power take-off 

to the bed frame. 

15. Remove the bolts securing the coupling housing (2) to the engine. 

16. Carefully pull the hydraulic power take-off back from the engine and move 

to the disassembly area. 

17. Remove the bolts securing the flexible coupling (1) to the flywheel. 

Remove the coupling. 

18. Do not remove the internal snapring (10) from the I.D. of the coupling 

spline unless visible damage has occured. 



Remove and disassemble the GP Control Valve 


Refer to the parts list and exploded view illustrations. 

1. Support the power take-off on a bench with the GP control valve up. Use 

fixtures or blocks under the power take-off to secure the unit in position. 

2. Remove six hex head capscrews (113) securing the (top) valve body 

(134) to the main regulator (center) valve body (115). Remove the valve 

body and the gasket (114). 

3. Remove four socket head capscrews (127) securing the main regulator 

valve body (115) to the ditch plate (131). Remove the valve body and 

the gasket (133). 

4. Remove the 6 socket head capscrews (130) securing the ditch plate 

(131) to the clutch housing (37). Remove the ditch plate and ditch plate 

gasket (137). 

Note: Do not remove the ditch plate unless visible damage has 

occured. 

5. Remove the socket head capscrew (123) and lock plate (122) and 

remove the proportional valve assemblies (125) from the valve body. 

6. Remove plug (126) from the valve body. 

7. Using a wrench on the hex body of the hydraulic relief valve (124), remove 

it from the valve body. 

Alternate design center section. 

8. Remove four hex head capscrews (146 & 154) from the covers. Remove 

the covers (145 & 153), hex nut (155), piston (152), spool (147), springs 

(149 & 150), washer (148) and o-ring (151). 

9. Remove the filter (142) and valve (143) from the valve body (115). 

10. Remove all remaining plugs, fittings, gaskets and o-rings. 

75

Disassembly 

76 


Remove the Coupling Housing, and disassemble the Gear Towers 


Remove the coupling housing. 

1. Remove 13 hex head capscrews (5) and remove the coupling housing 

from the front housing (6). 

Disassemble the first tower. 

Note: The gear towers may be configured to utilize one, two, 

three or four of the available drives. Those drives not used 

will be covered with steel plates and gaskets. the 

procedure below describes a typical gear tower 

configuration. The HPTO you are working on may be 

different, but the procedure will remain approximately the 

same for all configurations. 

2. Remove all pipes and fittings from the gear towers. 

3. If a pump is mounted on the tower, remove 4 hex head capscrews (102) 

and pull the pump (109) and gasket (101) from the tower. 

4. If there is no pump mounted on the tower, remove 4 hex head capscrews 

(102) and remove the cover (104) with gasket (101) from the tower. 

5. Remove 6 hex head capscrews (99) with copper washers (100) and 

remove the SAE mounting plate (98) with plate gasket (97) from the 

tower. 

6. Remove the driven gear (103) with ball bearings (96 & 105 ) from the 

housing. 

7. Remove 4 hex head capscrews (95) and remove the cover (93) with 

cover gasket (92) from the other side of the tower. 



tower. 

9. Using a bearing puller, remove the ball bearings ( 96 & 105) from the 

driven gear (103). 




Disassemble the second tower (in the same manner as steps 2 through 9). 

10. If a pump is mounted on the tower, remove 4 hex head capscrews (102) 

and pull the pump (109) and gasket (101) from the tower. 

11. If there is no pump mounted on the tower, remove 4 hex head capscrews 

(82) and remove the cover (94) with gasket (81) from the tower. 



gear tower. 

13. Remove the driven gear (83) with ball bearings (76 & 84) from the 

housing. 

14. Remove 4 hex head capscrews (75) and remove the cover (74) with 

cover gasket (73) from the other side of the tower. 



tower. 

16. Using a bearing puller, remove the ball bearings ( 76 & 84) from the 

driven gear (108). 

77

Disassembly 

Remove the Front Housing from the Clutch Housing 

78 


1. Position the HPTO with the front housing up. 


2. Remove 12 hex head capscrews (4) securing the front housing to the 

clutch housing (37). 

3. Using a hoist, carefully lift the front housing off the unit. 

Do not damage the idler gear (58), nor the splines of the gear and drive 

rings assy. (9) when the housing is being removed. 

4. Remove the housing gasket (56). 

Remove the idler gear 

5. Remove pipe plug (67) and drive out the dowel pin (66). 

6. Remove three 12 pt. capscrews (68) from the housing and idler gear. 

7. Remove the idler gear (58) with the bearing carrier (65), bearing (63), 

shims (57) and other components from the housing. 

8. Remove 4 hex head capscrews (62), 4 hex head capscrews (60), and 

the idler gear washers (61 & 59) from the idler gear (58). 

8. Remove the bearing carrier snapring (64) from the bearing carrier (65). 

9. Press the bearing carrier out of the idler gear. 



Disassemble the Clutch Housing 



1. Remove pipe plug (3) from the input end of the gear and drive ring assy. 

(9). 

2. Using a hoist and eyebolts, lift off the gear and drive ring assy. 

Note: The cylindrical bearing (11) outer race will be removed 

with the gear and drive ring assembly. The cylindrical 

bearing’s inner race will stay with the shaft. 

3. Remove the cylindrical bearing (11) outer race from the gear and drive 

ring assy. (9). 

4. Using a bearing puller, remove the outer race of cylindrical bearing (11) 

from the shaft. 

5. Remove the external snapring (15) from the shaft. 

6. Lift off the clutch hub (16). 

7. Lift off the stack of clutch friction plates (18) and steel clutch plates (17). 

8. Using a hoist and eyebolts, lift off the clutch piston (22). The piston carrier 

(20) and back plate (26) will be lifted off at the same time. 

9. Locate and dowel pin (33), which is located in the pocket of the shaft 

between the piston carrier and the shaft. 

10. Turn the clutch piston over on a bench. Remove the internal snapring 

(25) from the clutch piston. 

Note: The 9 springs (23) may have to be compressed to allow 

removal of the snapring. 

11. Support under the piston carrier. Using a soft mallet, carefully tap the 

clutch piston down off the carrier. 

12. Remove the back plate (26), 9 springs (23) and o-rings 

Note: Do not remove the 3 anti-rotation pins (29) unless 

damaged. 

79

Disassembly 

80 

13. Remove the last friction plate (28). 


14. Do not remove the 3 dowel pins (27) unless they are damaged. 

15. Turn the clutch housing unit over. Securly support the clutch housing unit 

with the output end of the shaft up. 

Models HP300S and HP600S only: (Models HP300I and HP600I skip to 

step 30.) 

16. Remove 6 hex head capscrews (43) and remove the front bearing 

retainer (44) with the oil seal (45). 

17. Remove the oil seal (45) from the retainer. 

18. Remove the retainer gasket (40). 

Model 300S only: (Models HP600S skip to step 25.) 

19. Remove the spacer (41) and second retainer gasket (40). 

20. Attach a hoist to the end of the shaft. Lift the shaft out of the clutch housing. 

The spherical bearing (38) will be removed with the shaft. 

21. Remove 4 seal rings (34) from the shaft (12). 

22. Remove the snapring (35) and the bearing spacer (36) from the shaft 

(12). 

23. Place the shaft and bearing in a press with press with the input end up 

and plates supporting beneath the inner race of the spherical bearing. 

Press the shaft out of the bearing. 

24. Remove the pipe plug (39) and pipe plug (48) from the clutch housing 

(37). 

Note: Remove the pipe plug (39) ONLY to clean the passageway 

in the event a catastrophic failure has occurred within the 

HPTO. 

Note: Do not remove the dowel pins (42), the housing spacer 

(140) or dowel pins (141) unless they are damaged. 

Models HP600S only: 

25. Remove inner race of bearing (51) from the end of the clutch shaft (12). 

Note: Remove the bearing race ONLY if it must be replaced. 





The inner race of bearing (38) will be removed with the shaft. 


28. Place the shaft and bearing in a press with press with the input end up 

and plates supporting beneath the inner race of the bearing. Press the 

shaft out of the bearing. 

29. Remove the pipe plug (39) and pipe plug (48) from the clutch housing 

(37). 

Note: Remove the pipe plug (39) ONLY to clean the passageway 

in the event a catastrophic failure has occurred withing 

the HPTO. 

Note: Do not remove the dowel pins (42), the housing spacer 

(140) or dowel pins (141) unless they are damaged. 

Models HP300I and HP600I only: 

30. Remove 6 hex head capscrews (47) and remove the front bearing 

retainer (46) with the oil seal (45). 

31. Remove the oil seal (45) from the retainer. 

32. Tap the bearing outer race (38) out of the retainer bore. 


The double cup bearing assembly (38) will be removed with the shaft. 


35. Using a small chisel, bend the tab(s) of the bearing lock washer (110) 

out of the slot (s) of the bearing lock nut (111). 

36. Remove the bearing lock nut. 

37. Remove the double cup bearing (38), including 2 cups, 2 cones and the 

spacer from the shaft 

81

Disassembly 

82 



Twin Disc, Incorporated Cleaning and Inspection 

Cleaning and Inspection 


General. 



Note: Replace all oil seals, gaskets, o-rings, piston rings, seal 

rings, snap rings, etc. as a part of any maintenance or 

overhaul procedure. Replace shims that are damaged or 

destroyed in disassembly. 

1. Clean all parts using EPA/OSHA-approved solvents or by steam 

cleaning. Parts must be dried and oiled immediately. 

Note: Do not steam clean clutch friction plates. If they are worn 

beyond use, replace them. 

2. Examine all parts carefully for grit, dirt and abrasives and reclean them 

if necessary. 

3. Clean all oil passages by working a piece of wire back and forth through 

them, and then flushing them with cleaning solvent. 

4. Use clean solvent to flush oil pumps, valves, etc. 

5. Flush all hoses, tubing, coolers, etc. particularly if the unit is being 

disassembled because of an internal failure. 

6. De-burr the housing and bearing carrier with a stone or file in the vicinity 

of all pusher screw locations. 

7. For previously sealed joints and joint surfaces, scrape surfaces to remove 

old gasket material or sealant. 

8. Clean surfaces with solvent to remove oil and grease residue. 

9. Test for clean surfaces by applying a few drops of cool water to the 

surfaces. Parts are sufficiently clean if water covers the surface in a film. 

If the water puddles or forms beads, use fresh solvent and reclean. These 

reactions indicate presence of an oil or other lubricant film. 

83


84 

Bearings. 


Note: Twin Disc, Inc. recommends replacing all used bearings 

as a normal practice during repair or rebuild of the HPTO. 

However, if the bearing will be reused, the following 

provides pertinent information prior to the bearing’s reuse. 

10. Thoroughly wash bearings in clean solvent if they have been in service. 

Soak bearings in solvent if they are particularly dirty. 

If a permanently-sealed bearing is used, never soak it in solvent. 

(Permanently-sealed bearings were not originally used in the HPTO 

design, but later engineering changes may have incorporated their use.) 

Never dry bearing with compressed air. Do not spin bearings while they 

are not lubricated. Oil bearings with SAE 10 engine oil immediately after 

cleaning. Be sure bearings are oiled before inspection. Protect clean 

bearings, whether they are new or have been in service, from dirt, dust, 

grit or any other contaminant. 

11. Inspect bearings for roughness of rotation. Replace the bearing if 

roughness is found. 

12. Inspect bearings for corrosion, scored, scratched, cracked, pitted or 

chipped races, and for indication of excessive wear of balls or rollers. If 

one of the these defects is found, replace the bearing. 

Preventing Entrance of Dirt Into Bearings. 

13. Dirt and grit in bearings are often responsible for bearing failure. 

Consequently, it is important to keep bearings clean. Do not remove 

grease from new bearings. Keep the wrapper on new bearings until 

immediately before they are to be installed. Do not expose new clean 

bearings until they are ready to be used in the assembly. Keep them 

wrapped in clean lint-free cloth or paper to keep out dust and debris. 

Protect bearings from contamination even after they are installed on the 

shaft or in the bore. 



Housings, Cast Parts and Machined Surfaces. 

14. Replace cast parts or housings that are cracked. 

15. Inspect bearing bores for grooved, burred or galled conditions that would 

indicate that the bearing has been turning in its housing. If the damage 

cannot be repaired to like-new condition with a fine crocus cloth, replace 

the part. Bore diameters must not exceed the maximum dimension 

shown under wear limits in the Description and Specifications 


16. Inspect bearing journals for grooved, burred or galled conditions that 

would indicate that the bearing inner race has been turning on the journal. 

If the damage cannot be repaired to like-new condition with a fine crocus 

cloth, replace the part. Bearing journals must not be less than the 

minimum diameters shown under wear limits in the Description and 

Specifications section of this manual. 

17. Inspect oil passages for obstructions. If an obstruction is found, remove 

it with compressed air or by working a wire or wire brush back and forth 

through the passage and flushing it with solvent. 

18. Inspect machined surfaces for burrs, nicks or scratches that have 

material that extends above the surface, and foreign matter. If such 

defects cannot be removed with crocus cloth or a soft stone, replace the 

part. 

19. Inspect threaded openings for damaged threads. Chase damaged 

threads with a tap of the correct size. 

20. Inspect dowel pins and dowel pin holes for wear or damage. Replace 

defective dowels. If a dowel pin hole is worn, re-bore and sleeve the 

hole when possible. If this cannot be done accurately, replace the part. 


Note: This applies where a matched set of parts is not involved. 

Shafts, seal lip contact surfaces and bearing journals. 

21. Inspect bearing journals for grooved, burred or galled conditions that 

would indicate that the bearing inner race has been turning on the journal. 

If the damage cannot be repaired to like-new condition with a fine crocus 

cloth, replace the part. Bearing journals must not be less than the 

minimum diameters shown under wear limits in the Description and 


85


86 


22. Inspect seal ring and seal lip contact surfaces. Look especially for 

scratches or nicks that intersect with or cross the contact area. If they 

cannot be removed using a very fine crocus cloth, replace the part. Seal 

contact area diameters must not be less than the minimum dimension 

shown under wear limits in the Description and Specifications 


23. Be sure the seal ring grooves and snapring grooves have straight sides, 

especially if a bearing failure has occurred. See figure 27. 

Figure 27. Inspect sealring grooves and snapring grooves 

24. Inspect threaded openings for damaged threads. Chase damaged 

threads with a tap of the correct size. 

Valve Seats. 

25. Inspect valve seats for burrs, nicks and scratches. If they cannot be 

removed with very fine crocus cloth, replace the part. Check to be sure 

that the valve is seating properly after reworking the valve seat. 

Splined parts. 

26. Inspect splines for stripped, twisted, chipped or burred splines. Remove 

burrs with a soft stone. If wear exists on the sides of the tooth, replace 

the part. Replace the part if other defects are found. 

Springs. 

Straight sides Damaged Wall 

Undamaged Groove Damaged Groove 

27. Inspect the springs for broken or distorted coils. Replace the spring if 

these or other defects are found. 



Clutch Plates. 

28. Inspect clutch plates, both friction plates and steel plates, for signs of 

overheating, pitting or excessive wear. Plates must be flat, not dished, 

distorted or bent. Inspect the steel clutch plates for wear on the external 

teeth. If wear exists on the sides of the tooth, replace the part. Replace 

the plates if these or other defects are found. 

Gears. 

29. Inspect gears for scuffed, nicked, burred or broken teeth. Inspect gear 

teeth for wear that may have destroyed the original tooth shape. Inspect 

internal bores or splines for wear or damage. If these or other defects 

cannot be removed with fine crocus cloth or a soft stone, replace the 

gear. 

Flexible Hoses. 

30. Inspect all hoses for cracks and sponginess. Replace damaged hoses. 

Pipes and Pipe Fittings 

31. Inspect all metal pipes for cracks and damage. If the pipe has been 

distorted or bent, especially if it has a crease or sharp bend in it, replace 

the pipe. Replace damaged pipe plugs or pipe fittings that have been 

damaged. Inspect for stripped threads and broken fittings. Replace all 

damaged parts. 


87


88 



Twin Disc, Incorporated Assembly 


Assembly Hint: 

Several components must be heated in an oven at 121° C. (250° 

F.) for one hour prior to assembly. Other components must be 

frozen in a freezer or dry ice for one hour prior to assembly. It is 

recommended that these components be prepared (heated or 

frozen) in advance of beginning the assembly process to avoid 

costly delays. Those components are: 

To be heated: 

(HP300S & HP600S only). 

Inner race of bearing (38). See figure 29. 

(HP300I & HP600I only.) 

Bearing (38). See Assembly step #10. (Clutch housing) 

(HP600S only). 


(HP300S, HP600S, HP300I & HP600I). 


Bearing (8). See figure 83. 

To be frozen: 

(HP300S & HP600S only). 

Dowel pins (42). See figure 40. 


(HP300S, HP600S, HP300I & HP600I). 



Dowel pin (66). See figure 95 

Assembly 

89

Assembly 

Clutch Shaft and Clutch Housing Assembly 

90 


Clutch housing. 



1. Position the clutch housing (37) so the bearing bore (output end) is up. 

HP600S only: (HP300S-skip to step 6, HP300I & HP600I-skip to step 10.) 

2. Tap or press the bearing outer race (38) straight into the bore with the 

back end of the bearing up. See figure 28. (Proceed to step 3.) 

Be sure to tap or press only on the outer race of the bearing. Do not 

Bearing 

contact the rollers. If the rollers become damaged, replace the bearing. 

Figure 28. Install the bearing in the clutch housing (HP600S) 

Clutch shaft. 

HP600S only 

3. Clean the bearing race I.D. (38) and clutch shaft (12) with EPA/OSHAapproved 

solvent to remove any oil or grease residue. 

4. Position the clutch shaft (12) with the input end up. 



5. Heat the inner race of the bearing (38) in an oven at 121° C. (250° F.) for 

one hour and install it immediately on the clutch shaft. Install the race 

from the input end of the shaft. See figure 29. The wide end of the 

bearing race must rest tightly against the shoulder of the shaft. Let the 

bearing race cool to room temperature after installation while continuing 

to apply downward force as it cools. This is necessary to ensure that it 

remains properly seated. (Proceed to step 18.) 


Note: An alternate method to install the bearing race is to use 

an arbor press to install the inner race of bearing (38) on 

the clutch shaft (12). Use a flat plate on top of a piece of 

steel tubing approximately 25 cm. (10 inches) long. The 

inside diameter of the tube must be just slightly larger than 

the O.D. of the bearing journal on the shaft. Press the race 

straight onto the shaft until it stops solidly against the shaft 

shoulder. 

Small end 

of race. 

Wide end 

of race. 

Figure 29. Install the bearing inner race on the shaft. 

HP300S only: 

6. Clean the bearing (38) and clutch shaft (12) with EPA/OSHA-approved 

solvent to remove any oil or grease residue. 

7. Heat the bearing (38) in an oven at 121° C. (250° F.) for one hour and 

install it immediately on the clutch shaft. Install the from the input end of 

the shaft. Let the bearing cool to room temperature after installation 

while continuing to apply downward force as the bearing cools. This is 

necessary to ensure that it remains properly seated. 

Note: An alternate method to install the bearing (38) is to use 

an arbor press to install it on the clutch shaft (12). Use a 

flat plate on top of a piece of steel tubing approximately 

91

Assembly 

92 


27 cm. (10.5 inches) long. The inside diameter of the tube 

must be just slightly larger than the O.D. of the bearing 

journal on the shaft. Press the bearing straight onto the 

shaft until it stops solidly against the shaft shoulder. 

8. After the race has cooled, install spacer (36) resting against the race. 

9. Securely install the snap ring (35) in the groove against the race. 

(Proceed to step 18.) 

Note: Prior to installation, feel the two edges of the I.D. of the 

snap ring to locate the sharpest edge. Install the snap ring 

so that sharpest edge is toward the input end of the shaft, 

away from the bearing and spacer. 

Be sure the snap ring is completely and securely seated 

all the way around the groove. 

HP300I and HP600I only: 

10. Support the clutch shaft (12) with the output end up. Heat the bearing 

(38) in an oven at 121° C. (250° F.) for one hour. 

Note: The bearing (38) used in HP300I and HP600I is a double 

-cup assembly. The components are furnished in matched 

sets. Do not mix or substitute components from other 

bearings. 

11. Quickly and carefully install the bearing cone, then a bearing cup, 

followed by the bearing spacer, a second bearing cone and the second 

bearing cup on the shaft. Immediately install the bearing lock washer 

(110) and the bearing lock nut (111) on the shaft and securely tighten it 

against the bearing. This is necessary to ensure that it remains properly 

seated tightly against the shoulder on the shaft while it is cooling to room 

temperature. Periodically retighten the nut to continue to apply downward 

force as the bearing cools. 

12. After the bearing has cooled to room temperature, usually requiring 

several hours, the nut must again be retightened. Using a spanner wrench 

or a large chisel and mallet, tighten the nut further. 



13. Use a .0381 mm. (.0015”) feeler gage to insure there is no gap between 

the bearing’s inner race and the shaft shoulder. Check all around the 

circumference of the shoulder. The feeler gage must not fit anywhere in 

the gap. 


Note: If the feeler gage reveals that the bearing is not tightly 

seated against the shoulder, the nut must be tightened 

more or the bearing must be seated in a press, using a 

heavy metal tube with an I.D. just slightly larger than the 

diameter of the shaft to press the bearing down further 

and eliminate the gap. 

The tube must press only against the inner race of the bearing. 

14. Next use the .0381 mm. (.0015”) feeler gage to insure there is no gap 

on either side of the bearing lock washer, between the lock washer and 

the upper bearing cone, or between the lock washer and lock nut. Again, 

check all around the circumference and use a spanner wrench or a large 

chisel and mallet to tighten the nut to eliminate both gaps, if they exist. 

15. When it is insured that no gap exists in any of the three locations 

described above, find the lock washer tab that most closely aligns in the 

middle of one of the four notches in the lock nut. Matchmark the tab and 

it nearest slot. 

16. Tighten the nut a partial turn more, just until a different notch 

becomes aligned with a tab. 

17. Using a hammer and chisel, carefully bend that tab of the bearing lock 

washer (110) up into the notch of the bearing lock nut (111). (Proceed to 

step 18.) 


18. Install four seal rings (34) in the grooves of the shaft. See figure 30. 

Lubricate the seal rings with an assembly lubricant to help prevent 

breakage when the shaft is installed into the clutch housing later in this 

procedure. 

93

Assembly 

94 

Figure 30. Install the seal rings on the shaft 


Note: After installation, rotate the seal rings in the grooves so 

the split lines of adjacent seal rings are 180 o apart. See 

figure 31. 

Split lines must 

be 180 o apart. 

Figure 31. Position the seal rings in the grooves 

Split lines must 

be 180 o apart. 


19. Position the clutch housing (37) so the bearing bore (output end) is up. 

Lubricate the seal ring bore of the housing to help prevent damage to 

the seal rings (34) as the shaft is installed into the housing. 

20. Using lifting equipment attached to the output end of the clutch shaft 

(12) lower the shaft unit into the clutch housing, taking special precautions 

to prevent damage to the seal rings (34) as they enter the housing bore. 

See figure 32. Gently lower the shaft until it stops. 


weight of the item being lifted. 




Note: HP600S: the shaft will be stopped when the bearing races 

come in contact with each other. 

Lubricate seal 

rings to prevent 

damage during 

assembly. 

HP300S: the shaft will be stopped when the bearing (38) 

seats in the housing bearing bore. 

HP300I and HP600I: the shaft will be stopped when the 

bearing race stops in the clutch housing bore. 

Figure 32. Install the shaft in the clutch housing. 

Do not damage 

seal rings. 

(Model HP300S 

is shown in 

illustration.) 

21. Install the (orifice) plug (48) in the clutch housing threaded hole 

immediately adjacent to the O.D. of the bearing (38). Install plug (39) in 

the housing if it was previously removed. See figure 33. 

Pipe Plug (48) 


Figure 33. Install the orifice plug (48) and plug (39) in the clutch housing. 

95

Assembly 

96 


HP600S and HP300S only: (HP300I & HP600I-skip to step 27.) 

22. Install oil seal (45) in the front bearing retainer (44). Coat the O.D. of the 

seal with sealant M2828 before installation. Rest the oil seal in the 

bore; the seal lip should be down, with the outer shell of the oil seal up. 

See figure 34. Use a flat steel plate slightly larger in diameter than the 

O.D. of the seal. Using the flat plate on top of the seal, press the seal 

straight into the bore until the steel plate stops against the surface of the 

carrier. The rear of the outer shell of the seal should be flush with the 

surface. Pre-lubricate the seal lip with clean No. 30 engine oil. 

Note: Press only against the outer shell of the seal. Do not 

damage the seal lip. 

Flat plate will stop 

against back of 

bearing carrier. 

Flat plate 

Oil seal (45) 

Bearing 

retainer (44) 

Figure 34. Install the oil seal in the bearing carrier (HP300S & HP600S). 

23. Place gasket (40) in position on the clutch housing. See figures 35 & 

36. 

The gasket must be positioned so the notch in the gasket is aligned 

with the (orifice) plug (48). See figures 35 & 36. THE ORIFICE IN THE 

PLUG MUST NOT BE COVERED, which would prevent lubricating oil 

flow to the bearing. 

Align the notch 

with the orifice 

fitting (48). 

Figure 35. Install the gasket with the notch aligned with the orifice. 



Figure 36. Install the gasket with the notch aligned with the orifice. 

HP300S only: (HP600S-skip to step 26.) 

24. Place the spacer (41) on top of the first gasket (40). Again, align the 

notch with the notch in the gasket and the orifice fitting. 

25. Place a second gasket (40) on the spacer. Align the notch as described 

above. (Proceed to step 26.) 

HP600S and HP300S only: 

26. Place the bearing carrier (44) on top of the gasket, install 6 hex head 

capscrews (43) to secure the bearing carrier to the clutch housing. See 

figure 37. Torque the capscrews to the proper specifications given in 

Torque Values for U.S. Fasteners in the Description and 


Do not cut the seal lip as is passes over the keyway of the shaft. 

Figure 37. Install the bearing retainer (44) (HP300S & HP600S). 


Align the notch 

with the orifice 

fitting (48). 

97

Assembly 

98 


HP600I and HP300I only: 

27. Install oil seal (45) in the bearing carrier (44). Coat the O.D. of the seal 

with sealant M2828 before installation. Rest the oil seal in the bore; the 

seal lip should be down, with the outer shell of the oil seal up. Use a flat 

steel plate slightly larger in diameter than the O.D. of the seal. See figure 

38. Using the flat plate on top of the seal, press the seal straight into the 

bore until the steel plate stops against the surface of the carrier. The 

rear of the outer shell of the seal should be flush with the surface. Prelubricate 

the seal lip with clean No. 30 engine oil. 



Flat Plate 

Flat plate will stop 

against back of 


Oil Seal (45) 

Bearing 

Carrier (44) 

Figure 38. Install the oil seal in the bearing carrier (HP300I & HP600I). 

28. Install the pipe plug (39) in the threaded hole near the bolt circle. See 

figure 39. Install the shaft in the clutch housing. 

Note: Check to be sure the plug is below the surface. 

Figure 39. Install the pipe plug (39). 




29. Install the o-ring seal (132) on the groove on the pilot of the bearing 

carrier. Lubricate the o-ring with assembly lubricant to help prevent it 

from being damaged during assembly. 

30. Using a hoist and lifting equipment, place the bearing retainer in position 

on the shaft and clutch housing. 

Use extreme caution to prevent damaging the o-ring and oil seal. 

31. Install 6 hex head capscrews (47) to secure the bearing carrier (44) to 

the clutch housing (37). Torque the capscrews to the proper specifications 

given in Torque Values for U.S. Fasteners in the Description and 



99

Assembly 

Belt Sheave Housing Assembly 

100 


HP600S and HP300S only: 

Note: HP300I & HP600I do not use belt sheave housings. 


Note: Freeze dowel pins (42), and dowel pins (141) if used, in 

a freezer or dry ice for approximately 1 hour prior to 

installation. 

1. Multiple dowel pin holes are provided to allow orientation of the belt 

sheave housing in any of several desired positions. If not already 

installed, drive 2 dowel pins (42) in the appropriate dowel pin holes to 

properly position the belt sheave housing for the application. 

2. If used, install the housing spacer (140), locating it on the appropriate 

dowel pins (42). See figure 40. 

Housing 

spacer 

Figure 40. Install the housing spacer (140) (HP300S & HP600S). 

3. Install two dowel pins (141) in the housing spacer, if used, locating them 

in the same holes as dowel pins (42). Again, leave 1/2 of each dowel 

pin protruding from the surface. 



4. Using a hoist and lifting equipment, install the belt sheave housing (46) 

on the clutch housing, carefully aligning it on the dowel pins (42 or 141). 

See figure 41. Secure with 6 hex head capscrews (47). Tighten the 

capscrews alternately and evenly. Torque the capscrews to the proper 

specifications given in Torque Values for U.S. Fasteners in the 

Description and Specifications section of this manual. 

Belt 

Sheave 

Housing 

Dowel 

Pin (141) 

Figure 41. Install the belt sheave housing (HP300S & HP600S). 

HP600S only: (HP300S-skip to step 10.) 



from the output end of the shaft. See figure 42. The wide end of the 

bearing race must rest tightly against the shoulder of the shaft. Let the 

bearing race cool to room temperature after installation while continuing 

to apply downward force as it cools. This is necessary to ensure that it 

remains properly seated. 


Dowel 

Pin (141) 

101

Assembly 

102 

Figure 42. Install the output bearing race (HP600S only). 


6. After the bearing inner race is cool, install the outer race of the output 

bearing (38) in the bore of the belt sheave housing (46). Tap into the 

bore but leave the race extending above the surface approximately 12.7 

mm. (1/2”). See figures 43 & 44. It will be properly positioned when the 

bearing retainer (50) is installed and securely bolted to the sheave 

housing. 

Note: Tap only against the outer race of the bearing. Do not 

damage the bearing rollers. 

Figure 43. Install the output bearing race (HP600S). 

Rear bearing 

inner race 

Rear bearing 

outer race 

Leave the 

rear bearing 

approx. 12.7 

mm. (1/2”) 

above the 

surface. 

Figure 44. Leave the output bearing extending out of the bore ( HP600S). 



7. Place the rear bearing retainer (50) in position on top of the bearing, 

aligning the bolt holes and orienting the grease fitting (49) at the top 12 

o’clock position. See figure 45. 

Rear 

bearing 

retainer 

Figure 45. Install the rear bearing retainer ( HP600S). 

8. Install 6 hex head capscrews (53) to secure the bearing retainer to the 

sheave housing. Tighten the screws alternately and evenly to draw the 

rear bearing race into the bore while the retainer is tightened against 

the sheave housing. Torque the capscrews to the proper specifications 



9. Install the grease fitting (49). 

HP300S only: 

10. Install the rear bearing (51) in the bore of the belt sheave housing (46). 

Tap the bearing to the bottom of the bore. See figure 46. 


Note: Tap only against the outer race of the bearing. Do not 

damage the bearing rollers. 

Figure 46. Install the rear bearing (HP300S ). 

103

Assembly 

104 


11. Install snap ring (52) in the groove on the shaft to retain the rear bearing 

(51). 



so that sharpest edge is toward the input end of the shaft, 

away from the bearing and spacer. 



12. Place the rear bearing retainer (50) in position on top of the bearing, 

aligning the bolt holes and orienting the grease fitting (49) at the top 12 

o’clock position. See figure 47. 

Rear 

bearing 

retainer 

Figure 47. Install the rear bearing retainer ( HP300S). 

13. Install 6 hex head screws (53) to secure the bearing retainer to the sheave 

housing. Tighten the screws alternately and evenly to tighten the retainer 

against the sheave housing. Torque the capscrews to the proper 



14. Install the pipe plug (54) in the threaded hole in the inside of the sheave 

housing. 

15. Install the grease fitting (49). 

Hex Head 

Capscrews 

Hex Head 

Capscrews 



Clutch Assembly 


HP300S, HP600S, HP600I and HP300I: 

1. Turn the unit over so the front of the clutch housing is up. See figure 48. 

Note: 

Typical HP300S or 

HP600S model is 

illustrated. 

Figure 48. Turn the unit over with the clutch housing up. 

2. If 4 anti-rotation dowel pins (27) were removed, install them in the dowel 

holes on the inside of the clutch housing. The dowels must be installed 

with 10.92 mm. (.430 inches) max. extending above the surface of the 

clutch housing. See figures 49, 50 & 51. 


Note: Freeze dowel pins (27) in a freezer or dry ice for 

approximately 1 hour prior to installation. 

105

Assembly 

106 

Installation tool 

with dowel pin 

in place ready 

to be installed. 

Figure 49. Dowel pins (27) and installation tool. 

10.92 mm. (.430”) Max. 

Figure 50. Position the dowel pin in the clutch housing hole. 

Figure 51. Install 4 anti-rotation dowel pins (27). 


Anti-rotation 

Dowel Pins 

Clutch housing 

surface 

Dowel Pin 

Anti-rotation 

Dowel Pin 



3. Place 1 friction plate (28) inside the clutch housing (37) with the external 

teeth meshing with the 4 dowel pins. See figures 52, 53, & 54. 

Figure 52. Install friction plate (28). 

Figure 53. Friction plate teeth aligned with dowel pins. 

Dowel pin 

Figure 54. Friction plate installed and aligned on dowel pins. 


Friction Plate 

Dowel pin 

Friction plate 

Dowel pin 

107

Assembly 

108 


4. Install the pin (33) in the pocket in the side of the shaft. Stick the pin in 

the groove using an assembly grease. The grease will hold the pin in 

place during assembly. Mark the shaft with a black marker to indicate 

the location of the pin during further assembly procedures. See figures 

55 & 56. 

Mark the 

shaft. 

Pin (36) 

Assembly 

Grease 

Figure 55. “Stick the pin (33) in the hole of the shaft. Mark the shaft. 

Figure 56. Matchmark the shaft in line with dowel pin (33). 

Be sure to 

also 

matchmark 

the shaft near 

the splines. 



Clutch Piston, Piston Carrier and Back Plate Unit. 

Figure 58. Dowels installed from side opposite the notch. 

6. Place the piston carrier in the clutch piston (22) (before the o-rings are 

installed). The three dowels must enter the holes in the clutch piston. 

See figure 59. 


Note: If previously were removed, freeze dowel pins (29) in a 

freezer or dry ice for approximately 1 hour prior to 

installation. 

5. Position the piston carrier (20) with the notch down. Brace beneath the 

carrier at a location just outside the 3 pin holes. When frozen, quickly 

press three dowel pins (29) in the piston carrier (20). See figures 57 & 

58. 

Support just 

outside the 

dowel pin 

holes. 

Figure 57. Install dowels in piston carrier. 

Side without 

the notch is 

up. 

Press tight 

against the 

surface. 

Notch 

Dowel is 

installed from 

the side 

without the 

notch. 

Note: The clutch piston is installed in the piston carrier before 

the seal rings are installed ONLY for the purpose of 

alignment and match-marking the parts. The seal rings 

must be installed for final assembly. 

109

Assembly 

110 

Large end of 

dowel pins 

must enter 

holes in the 

piston. 

Figure 59. Dowels must enter holes in the clutch piston. 

Figure 60. Matchmark the clutch piston and piston carrier. 


7. Matchmark the piston carrier (20) and clutch piston (22) to facilitate later 

assembly. See figure 60. (Before the o-rings are installed.) 

Matchmark 

the piston 

carrier and 

clutch piston. 

8. Remove the match-marked piston carrier from the clutch piston. Install 

one seal ring (19) and one seal ring (21) on the piston carrier (20). Be 

careful the seal rings are not damaged during installation. Lubricate the 

seal rings with an assembly lubricant in preparation for further assembly. 


Note: Install the smaller of the seal rings in the groove on the 

side opposite the notch. 

Note: The remaining seal ring (19) will not be installed at this 

time, to avoid damage that can occur during assembly. 



Install seal ring 

(21) in the large 

groove of the 

piston carrier. 

Seal ring. 


Install one seal ring 

(19) in the groove on 

the piston carrier. 

Notch. 

Figure 61. Install seal rings on the piston carrier. 

9. Generously lubricate the bore of the clutch piston (22) and the seal rings. 

Place the piston and piston carrier on the bed of a press. Perfectly 

align the matchmarks and press the piston carrier in the clutch piston. 

Press the piston carrier to the bottom of the bore. See figures 59 & 60. 

10. Install the back plate (26) (before the seal ring (24) is installed, aligning 

the dowel pin holes. Matchmark the back plate and clutch piston (22). 

See note in step 8 above. 

11. Now remove the back plate and install the 2nd seal ring (19). See figure 

61. 

12. Install the seal ring (24) in the external groove of the back plate (26). Be 

careful the seal ring is not damaged during installation. Lubricate the 

seal ring with an assembly lubricant in preparation for further assembly. 


Figure 62. Install the seal ring on the back plate. 

Do not install 2nd 

seal ring here until 

later in this assembly 

procedure. 

Back 

Plate. 

111

Assembly 

112 


13. Install the nine springs (23) in the back plate (26). See figure 63. 

Note: It is imperative that the springs “stick” in the holes. Use an 

oil-soluble assembly grease to hold the springs in the 

holes during assembly. 

Use assembly 

grease to 

“stick” the 

springs in the 

pockets. 

Figure 63. “Stick” the springs in the back plate. 

14. Install the back plate (26) in the clutch piston (22), aligning the marks so 

the dowel pins enter the 3 pockets. Press the back plate down as far as 

it will go. Using a small arbor press, compress the springs until the back 

plate is below the snap ring groove. See figure 64. 

Note: If the dowels are not perfectly aligned with the holes in the 

clutch piston, the back plate cannot be moved to a point 

below the snap ring groove. 

Springs 

Seal ring 

(24) 

Do not damage the dowel pins or dowel pin holes in the clutch piston. If 

excessive resistance is met while compressing the back plate into the 

clutch piston, the dowels may not be properly aligned with the holes. 

Relieve the pressure on the back plate, align the matchmarks and 

reinstall. It may be necessary to repeat steps 9 thru 14 to more precisely 

match-mark the parts. 



Press tool Press tool 

Snapring (25) 

Figure 64. Compress the springs. 

15. While holding the back plate in that position install the internal snap ring 

(25) in the groove of the clutch piston. See figure 65. 


Note: Be sure the snap ring is completely and securely seated 


Snapring 

securely 

seated in 

groove. 

Figure 65. Install the snap ring in the clutch piston. 

Note: A pre-check of piston function and a check for leaks with 

air pressure is advised. 

16. Check to be sure the seals have not been damaged during assembly 

and the clutch functions properly. Direct approximately 30 p.s.i. air into 

the clutch pressure passageway in the I.D. of the piston carrier. See 

figure 66. Listen and look for signs of leakage in the clutch area. Use 

approximately 207 kPa. (30 psi.) air pressure to operate the piston and 

check for air leaks. 

113

Assembly 

114 

Clutch 

pressure port 

Notch 

Seal ring 


Figure 66. Location of clutch pressure port in the I.D. of the piston carrier. 

17. Turn the clutch piston unit over. Install seal rings (30, 31 and 32) in the 

grooves located in the bore of the piston carrier (20). Be careful the 

seal rings are not damaged during installation. Lubricate the seal rings 

with an assembly lubricant in preparation for further assembly. See 

figures 66, 67 & 68. 

Figure 67. Install seal rings in the I.D. of the piston carrier. 

Seal ring 

Notch 

Figure 68. Install seal rings in the clutch piston bore. 

Sealring 

grooves 

Mark the 

Piston Carrier. 

Seal ring 

grooves 



18. Locate the notch in the I.D. of the piston carrier. See figures 66 & 68. 

That notch will fit over the pin that was “stuck” in the shaft with grease in 

a previous step. See figure 55. Place a mark on the piston carrier to 

indicate the location of the notch. Align the piston carrier notch with the 

black mark previously drawn on the shaft and install the piston carrier 

unit on the shaft. See figure 69. 


Note: Use lifting equipment to lower the unit onto the shaft. 

Do not force the clutch piston unit into position. Use a slight rocking 

motion to “help” the seal rings move over the shoulders on the shaft. 

DO NOT MOVE THE PART ROTATIONALLY. A slight imperfection on the 

shoulder could cause the seal rings to be cut during assembly. 

Figure 69. Align the matchmarks during assembly. 

Figure 70. Install the piston carrier on the shaft. 

Align 

matchmarks 

115

Assembly 

116 


Note: Check carefully to be sure the dowel pin (36) was not 

dislodged from its pocket during assembly. When properly 

seated, the top edge at the I.D. of the piston carrier will be 

located even with the shoulder of the clutch shaft and the 

dowel pin will prevent rotation of the clutch piston assembly 

on the shaft. See figure 71. 

Shaft 

shoulder 

Piston carrier 

top surface 

Figure 71. Check to be sure clutch piston unit is properly seated. 

19. Check to be sure seals have not been damaged during assembly and 

the clutch functions properly. See figure 72. Plumb an air source into 

the clutch pressure port located in the side of the clutch housing (37). 

Use approximately 207 kPa. (30 psi.) of air pressure. While pressurizing 

the port, listen and look for signs of leakage in the clutch area. 

Assembly hint: 

Add a small amount of oil in the pressure port to help seal the 

shaft rings. 

Plumb air into 

the clutch 

pressure port 

to test. 

Figure 72. Check for pressure leaks. 



Clutch Hub, Clutch Plates and Gear & Ring Assembly. 

See assembly hint in step 23 and note in step 24 before proceeding. 

20. Place the clutch hub on the bench (or in an assembly fixture similar to 

the one described in step 24 below) with the splined portion up. Install 

one clutch friction plate (18) on the hub. Visually center the plate on the 

hub. 

21. Install one steel clutch plate (17) on the top of the friction plate. Use the 

steel plate to center the friction plate more exactly. 

22. Alternately install the remaining 7 friction plates and 7 steel clutch plates 

on the clutch hub until a total of 8 friction and 8 steel plates are on the 

stack. A steel clutch plate will be the top plate on the stack. 

23. Perfectly align the stack of plates before assembly onto the clutch shaft. 



The gear and drive ring assembly (9) may be used as an alignment 

guide. Carefully place the clutch hub with the plate stack into the 

gear and drive ring assembly, meshing the external teeth and 

visually centering the plates and hub in the process. 

24. While preventing the plates from moving relative to each other and the 

clutch hub, turn the hub over and place the stack on the clutch shaft. 

Note: Although the plates may also be aligned using 2 or 3 dowel 

pins, small rods or flat plates spaced evenly in the teeth to 

align the plates, a fixture similar to the one in figures 73 

& 74 may be used to aid this process. The black “handles” 

are attached to tubes that rotate. The bottom end of each 

tube has a “foot” that retains the plates and clutch hub. 

The I.D. of the fixture housing is splined to locate the friction 

plates. After the components are installed on the clutch 

shaft, rotate the “handles” to release the plates and remove 

the fixture. 

117

Assembly 

118 

Figure 73. Fixture being used for assembly. 


Fixture 

Handles 

rotate 

Figure 74. Using an alignment and installation fixture for installation. 

25. While compressing the springs (23) install the external snap ring (15) to 

retain the hub and plates on the clutch shaft. See figure 75. 

Note: The following installation (see figures 75 & 76) shows a 

simple method of holding the springs in a compressed 

position to allow for installation of the snap ring. A threaded 

rod was installed in the hole in the end of the clutch shaft. 

A straddle fixture was used to press against the piston 

carrier. Spacers were used on the threaded rod beneath 

a washer and nut. When the nut is tightened against the 

spacers, the straddle fixture presses against the piston 

carrier to compress the springs. 



Rod threaded 

into end of 

clutch shaft 

Figure 75. Compress the springs to install the snap ring (15) 

Figure 76. Install the snap ring (15) 



from the input end of the shaft. See figures 77 & 78. The wide end of 

the bearing race must rest tightly against the shoulder of the shaft. Let 

the bearing race cool to room temperature after installation while 

continuing to apply downward force as it cools. This is necessary to 

ensure that it remains properly seated. 

Inner race of 

the bearing 

Figure 77. Bearing inner race. 


Spacers 

Straddle 

Fixture 

119

Assembly 

120 

Bearing 

outer race 

Bearing 

inner race 

Figure 78. Install the bearing inner race. 


27. If previously removed, install the pipe plug (13) and press two ball plugs 

(14) in the end of the clutch shaft (12). See figure 79. 

Pipe plug 

Ball plug 

Figure 79. Ball plugs and pipe plug. 

Ball plug 


If carefully used in a manner that prevents damage of the 

components, the gear and ring assembly may be used as a tool 

to align the friction plates prior to installation of the bearing outer 

race. 



28. Apply assembly grease to the bore of the gear and ring assembly (9) to 

prevent the outer race from falling out during further assembly. See figure 

80. Install the outer race of the bearing (11) in the bore of the gear and 

ring assembly (9). See figure 81. 


Generously 

apply 

assembly 

grease in the 

bore to hold 

the race 

during further 

assembly 

Figure 80. Apply assembly grease the gear and drive ring bore. 

Bearing outer 

race 

Figure 81. Install the bearing outer race in the gear and drive ring bore. 

Note: The friction plates (18) must be perfectly aligned and 

centered before the gear and drive ring assembly (9) is 

installed. A pair of straight edged measurement scales, 

flat plates or metal dowel rod may be used to perfectly 

align the teeth and center the plates for further assembly. 

29. Install the gear and drive ring assembly (9) on the clutch shaft. The internal 

teeth must mesh with the teeth of the clutch friction plates (18). The inner 

and outer races of the bearing (11) will position the components when 

they come into contact. See figure 82. 

121

Assembly 

122 


Lower the unit gently onto the shaft to prevent damage to the bearing. 

DO NOT FORCE the gear and drive ring assembly into position on the 

shaft. If resistance is met, the external teeth of the clutch friction plates 

may be misaligned. STOP, realign the plates and continue to install the 

gear and drive ring assembly. 

Do not 

damage the 

bearing. 

Bottom plate. 

Use lifting 

equipment. 

Gear and 

drive ring 

assembly 

Carefully 

mesh the 

teeth. 

Figure 82. Install the gear and drive ring assembly on the shaft. 

Warning: 

Check the bottom plate to make sure its teeth are engaged inside the 

gear and ring assembly. This can be done both visually and by feeling 

all around the circumference of the gear and drive ring assembly with 

the hands to be sure the teeth do not protrude in any area. 



30. Heat the bearing (8) in an oven at 121° C. (250° F.) for one hour and 

install it immediately on the clutch shaft. Install the race from the input 

end of the shaft. Install the bearing on the gear and drive ring assembly 

(9) See figure 83. Let the bearing race cool to room temperature after 

installation while continuing to apply downward force as it cools. This is 

necessary to ensure that it remains properly seated. 

Figure 83. Install the bearing (8). 


Bearing 

123

Assembly 

Assemble the Front Housing Unit/Install Idler Gear 

124 


Front housing 


1. Apply a thread sealant on the pipe plug (orificed) (85) and install it in the 

bottom of the manifold hole in the front housing (6). See figure 84. 

Figure 84. Install the (orifice) plug. 

Pipe plug 

(orifice) (85) 

2. Position the front housing on the bench with the output end up. Place 

the bearing carrier (65) in the housing. Align the three bolt holes, but it is 

not imperative that they be perfectly aligned until later assembly. 

Note: Be sure the surfaces of the front housing and the bearing 

carrier are clean. 

3. Using a feeler gauge, measure the shim gap between the top of the 

bearing carrier and the under side of the housing. See figure 85. Record 

the width of the gap as determined by the feeler gage reading. 

Use feeler 

gauge to 

measure 

the gap. 

Bearing 

carrier (65) 

Figure 85. Measure for shims. 

Front 

housing (6) 



4. Select shims (57) equal to the amount of the gap. Set the shims aside 

for later installation. Refer to Shim Tolerance for bearing carriers (65) 

in idler gear (58) in the Description and Operation section for exact 

designed shim tolerance. 

5. Press the bearing (63) in the idler gear (58). See figures 86 & 87. 

Press until the bearing is flush with the surface of the gear. 


Note: Press only against the outer race of the bearing. 

Tool stops against 

surface of idler gear. 

Figure 86. Install the bearing (63) in the idler gear (58). 

Pressing tool 

Bearing (63) 

Pressing tool 

Bearing (63) 

Bearing is 

flush with 

surface of 

gear. 

Figure 87. Bearing (63) installed flush with the idler gear (58) surface. 

125

Assembly 

126 


6. Press the bearing carrier (65) into the bearing (63). See figure 88. 

Press until the shoulder is tight against the I.D. of the bearing. 

Support beneath the inner race of the bearing before pressing in the 

bearing carrier. Failure to do so may cause the bearing to be damaged, 

resulting in premature, catastrophic failure. 

Figure 88. Installed the bearing carrier. 

7. Place the idler gear washer (59) on the gear and secure with four hex 

head capscrews (60). See figures 89 & 90. Torque the capscrews to 

the proper specifications given in Torque Values for U.S. Fasteners 

in the Description and Specifications section of this manual. 


Rest the lower end of the bearing carrier on the bed of the press 

and hold tight with the press ram while tightening the capscrews. 

Press ram 

Press ram 

Bearing 

carrier 

12345678 

12345678 

12345678 

12345678 

123456789012345678 

123456789012345678 

123456789012345678 

123456789012345678 

Figure 89. Install the idler gear washer (59). 

Bearing 

carrier 

Idler gear 

washer (59) 

Hex head 

capscrew (60) 

Support directly 

beneath the 




Figure 90. Hold the unit while torquing the hex head capscrews (60). 

8. Turn the gear over on the bed of the press. Install the other idler gear 

washer (61) on the gear and secure with four hex head capscrews (62). 






Again, rest the lower end of the bearing carrier on the bed of the 

press and hold tight while tightening the capscrews. 

9. Install the snap ring (64) on the bearing carrier (65). See figure 91. 



so that sharpest edge is up, away from the gear. 

Sharp side 

of snap ring 

to be up. 



Figure 91. Install the snap ring. 

Snap ring (64) 

Snap ring 

groove 

127

Assembly 

128 


10. Place the idler gear unit in position in the front housing (6). Align the 

three bolt holes with the holes in the housing. See figure 92. 

Note: The wide shoulder of the bearing carrier must be up, 

toward the output side of the front housing (6). 

11. Place the proper amount of shims (57) as previously determined by 

measuring the shim gap on top of the bearing carrier. Align the bolt 

holes in the shims with the holes in the bearing carrier and front housing. 


Align holes 

with 2 large 

punches. 

Figure 92. Place the gear unit and shims in the housing. 

Output side 

of front 

housing (6) 

is up. 

Install 

shims (57). 

Wide side 

of bearing 

carrier (65) 

12. Place two large punches or tapered rods into the bolt holes as alignment 

tools while the first of three 12 pt. capscrews (68) is installed. 

Raise the housing to gain access to the under side (input side) of the 

housing. See figures 93 & 94. Coat the threads of the first capscrew 

with thread sealant and install it in one of the three bolt holes. Hand 

tighten. 

Figure 93. Raise the housing for access to the lower side. 



13. Remove one of the alignment tools and install a second 12 pt. capscrew 

(68). Again, use thread sealant on the threads before it is installed. Hand 

tighten. 

14. Remove the second alignment tool and install the remaining 12 pt. 

capscrew (68) with sealant on the threads. Hand tighten. 

15. Torque the capscrews to the proper specifications given in Torque 


section of this manual. See figure 94. Lower the housing to rest securely 

on the bench. 

Thread 

sealant 

Torque 

wrench 

Figure 94. Install, tighten and torque three 12 pt. capscrews (68). 

16. Freeze the dowel pin (66) in a freezer or dry ice for one hour. When the 

dowel is frozen, quickly install and drive the dowel into the hole in the 

middle of the three 12 pt. capscrews. See figure 95. 


12 pt. 

capscrews 

(68) 

Note: Lubricate the dowel pin hole with anti-seize compound 

prior to installing the dowel pin. 

Figure 95. Insure that the dowel is below the surface. 

Dowel pin 

must be 

installed 

below the 

surface. 

Capscrew 

holes 

129

Assembly 

130 


17. Coat the threads of pipe plug (67) and install it in the threaded hole at 

the front side of the dowel pin hole. 

18. Coat the threads on both ends of the pipe nipple (87) and install it in the 

housing. Install the manifold (86) on the pipe nipple. Rotate the manifold 

so it’s bottom side will be parallel to a horizontal centerline when the 

HPTO is installed on the engine. See figure 96. 

Figure 96. Install manifold (86). 

Bottom of 

manifold to be 

horizontal 

Imaginary 

horizontal line. 

Manifold (86) 

Bottom of 

manifold 

Pipe nipple 

(87) 



Install the Front Housing on the Clutch Housing 


Turn the front housing over on the bench with the front side up. 

1. Install guide dowels in two threaded holes of the front housing (6). See 

figure 97. Locate the guides 180 o apart. 

2. Install the gasket (56) on the clutch housing (37). See figure 97. Align 

the holes. Use a small amount of assembly grease to “stick” the gasket 

on the housing so it does not move during assembly. 

3. Using lifting equipment, and with the housing suspended in a horizontal 

position, install front housing (6) on the clutch housing (37). See figures 

97 & 98. Be sure the front housing is aligned so the gear towers will be 

at the top of the unit (see note below) aligned with the control valve 

assembly when the HPTO is installed on the engine. 


Note: Suspend the front housing in a perfect horizontal position. 

Use hoisting equipment attached at three points as shown 

in figure 97. 

Note: As the gear housing is lowered onto the clutch housing, 

the guides dowels will first enter the bolt holes in the clutch 

housing. Then the bearing (8) will enter the bore of the 

gear housing and the idler gear will contact the teeth of 

the gear and drive ring assembly. Rotate the idler gear so 

the teeth mesh properly. When properly aligned the gear 

housing will rest properly on the clutch housing. 

Note: On some applications the gear housing is rotated as much 

as two (2) bolt holes from the top. (See caution and 

warning that follow.) 

Regarding repositioning of the gear housing: DO NOT ROTATE MORE 

THAN two (2) bolt holes from the top as described in step 3 above. To 

do so would cause the drain holes to be mislocated at the bottom of the 

housing and would prohibit proper gravity drainage of the oil from the 

housing. 

Units that do not drain properly will overheat, resulting in malfunction 

and/or catastrophic failure. 

131

Assembly 

132 

Guide 

dowel 

Guide dowel 


Figure 97. Hoist equipment should be attached at three points. 

Figure 98. Guide dowels enter holes in clutch housing. 

Front 

housing 

Clutch 

housing 

4. Install 12 hex head capscrews (4) from the bottom side to secure the 

housing. Torque the capscrews to the proper specifications given in 



Coupling Housing 

Suspend from 

three points. 

Gasket is “stuck” 

to underside with 

grease. (May also 

be placed on the 

clutch housing but 

do not damage 

with the guide 

pins.) 

5. Install the coupling housing (2) on the front housing. See figure 99. 

Secure with 13 hex head capscrews (5). Torque the capscrews to the 

proper specifications given in Torque Values for U.S. Fasteners in 

the Description and Specifications section of this manual. 



Figure 99. Install the coupling housing. 


Coupling 

housing 

Front 

housing 

6. Install the oil seal (7) in the bore of the front housing (6). Coat the O.D. of 

the seal with sealant M2828 before installation. Rest the oil seal in the 

bore; the seal lip should be down, with the outer shell of the oil seal up. 

See figure 100. Press the seal straight into the bore until the assembly 

tool stops against the surface of the carrier. The rear of the outer shell of 

the seal should be flush with the surface. Pre-lubricate the seal lip with 

clean No. 30 engine oil. 


Figure 100 shows an assembly tool that will safely and correctly 

install the oil seal. It consists of two parts, an inner shaft protector 

and seal lip guide that fits over the end of the shaft and an outer 

component that is designed to contact the outer shell of the seal. 

The outer component must have an O.D. greater than the O.D. of 

the seal so the tool will be stopped by the surface of the housing 

to properly locate the seal. 

If such tool is not available, it is recommended that a flat ring with 

an I.D. slightly larger in diameter than the seal lip and O.D. slightly 

larger than the O.D. of the seal be used to install the seal. Press 

or tap on the flat plate working 360 o around the ring a little at a 

time until the ring stops against the surface of the housing. 

Do not tap directly on the seal housing to install it. The seal housing will 

become damaged and bent, resulting in oil leaks. 



133

Assembly 

134 

Outer 

component of 

assembly tool 

Inner 

component of 

assembly tool 

Hex head 

capscrews (5) 

Figure 100. Install the oil seal. 

Figure 101. Install the pipe plug. 


O.D. must be 

larger than 

O.D. of the oil 

seal. 

Press oil seal 

flush with 

housing 

surface. 

7. Install the pipe plug (3) in the end of the shaft (12). See figure 101. 

Pipe plug 



Assemble the Gear Drive Towers 




Note: HPTOs that are designed with gear drive towers may be 

equipped to drive from either the front or rear of either of 

the towers, depending upon the BOM and design 

parameters of the installation. In such cases, one, two, 

three and/or four drives may be used. Refer to the BOM 

for your unit for exact design features. 

Note: The SAE plates are of two basic designs; flat and 

contoured. See figure 102. 

Flat design 

(plate side illustrated) 

Figure 102. SAE plate configurations. 

Note: The SAE plates are of two basic thicknesses; a wide 

thickness and a narrower thickness. One wide SAE plate 

and one narrow SAE plate are used on each tower. See 

figures 102 & 103. 

Wide 

SAE plate 

Narrow 

SAE plate 

“Countoured” design 

(bearing side illustrated) 

Narrow 

thickness 

Wide 

thickness 

Use one wide SAE 

plate and one 

narrow SAE plate 

on each tower. 

Figure 103. Top view of tower with wide and narrow SAE plates. 

135

Assembly 

136 


Note: The SAE plates are available in several SAE sizes “A,” 

“B,” and “C.” Flat designs and contoured designs are not 

necessarily available in all SAE sizes. Refer to the BOM 

for your unit for exact design features. 

Note: Driven gears have a “long” side and a “short” side. It is 

imperative that the “long” side of the gear be installed 

on the side with the wider SAE plate. 

Note: The assembly procedure as described below refers to 

typical tower configurations. The procedure describes a 

typical installation and is applicable to any of the 

configurations or combinations of components. The 

photos used show typical contoured SAE plates being 

used at both front and rear positions of both towers. 

Hex head 

capscrew 

Copper 

washer 

Refer to the specific BOM for your HPTO; the drives may 

be designed with the drives in different locations. 

Figure 104. SAE mounting plate and associated components. 

Tower #1 

Hex head 

capscrew 

Cover 

Gasket 

SAE Mounting 

Plate 

Gasket 

1. Install two guide dowels in the front housing (6), 180 0 apart from one 

another. See figure 105. 



2. Install the gasket (69) on the front side of the tower. See figures 105 

and 106. 

Gasket 

Figure 105. Install guide dowels to align the SAE plate. 

3. Locate the SAE mounting plate (70) on the guide bolts. See figure 

106. 


Note: The hole for the fitting must be toward the outside. 

Figure 106. Set the SAE mounting plate in position on the guides. 

4. Carefully tap the SAE plate down tight against the gasket. See figure 

107. 

Figure 107. Tap the SAE mounting plate into position. 

Use guide 

dowels to 

align the 

gasket and 

SAE plate. 

Note location 

of hole for 

the fitting. 

137

Assembly 

138 


5. Install 5 hex head capscrews (71) with copper washers (72) to secure 

the plate to the housing. See figure 108. Torque the capscrews to 48.8 

Nm. (36 lb. ft.). 


Do not install the copper washer and hex head capscrew nearest 

the hole for the fitting until after the fitting is installed. The head of 

the capscrew will interfere with the fitting as is rotated into the 

hole. See illustrations in figure 109. 

Figure 108. Install one copper washer with each hex head capscrew. 

6. Install the pipe fitting in the hole. See figure 109. 

Fitting 

Capscrew 

prevents 

rotation of 

the fitting 

Hex head 

capscrew 

Copper 

washer 

Figure 109. Install the fitting before the hex head capscrew and washer. 

7. Install the last hex head capscrew (71) with copper washer (72). See 

figure 109. Torque the capscrew to 48.8 Nm. (36 lb. ft.) 

8. Install the cover (74) with gasket (73) on the plate. Install 4 hex head 

capscrews (75) to secure the plate to the SAE mounting plate (70). See 

figure 110. Torque the capscrews to the proper specifications given in 





Typical 

4-bolt cover 

Figure 110. Install the fitting before the hex head capscrew and washer. 

9. Identify the “long” and “short” ends of the driven gear (83). See figures 

111 & 112. 

Figure 111. Identify the long and short ends of the driven gears. 

Bearing 

Figure 112. Driven gear and bearings 


Driven Gear 

Bearing 

journal 

Long 

End 

Short 

End 

Long Short 

Cover 

SAE 

mounting plate 

Note: 

2-bolt cover 

is shown. 

Bearing 

Bearing 

journal 

139

Assembly 

140 


10. Press the bearing (63) onto the long end of the driven gear (83). See 

figure 113. Press the bearing tight against the shoulder on the gear 

Press only against the inner race of the bearing to prevent damage that 

may result in premature catastrophic failure. 


Figure 113 shows a metal pipe being used as a press tool. The 

I.D. of the tool is just slightly larger than the I.D. of the bearing 

inner race and the O.D. of the tool does not contact the bearing 

balls, cages or outer race. 

Figure 113. Press the first bearing on the gear. 

11. Press the bearing (84) onto the short end of the driven gear (83). See 

figures 114 & 115. Press the bearing tight against the shoulder on the 

gear. 

Figure 114. Install the 2nd bearing on the driven gear. 

Press tool 

Bearing 

Gear 

Press tool 

2nd Bearing 

Gear 

1st Bearing 



Figure 115. Both bearings seated on the gear. 

Figure 116. Install the driven gear in the housing. 


2nd Bearing 

1st Bearing 

12. Install the driven gear into the front SAE mounting plate through the hole. 

See figure 116. The long end of the gear must be toward the side with 

the wide SAE plate. See information with figures 111 & 112. 

Note: When the bearing on the lower side of the driven gear is 

properly seated in the bearing bore of the SAE plate, the 

teeth of the driven gear will be located in the middle of the 

teeth of the idler gear. See figures 116 & 117. If they are 

not aligned so contact is in the middle of the tooth, the 

driven gear is improperly installed or the wrong SAE plate 

is installed on the front side of the tower. 

Idler gear 

teeth 

Driven gear 

teeth 

141

Assembly 

142 

Figure 117. Gear teeth must mesh properly. 


13. Install two guide dowels in the front housing (6), 180 0 apart from one 

another. See figure 116. 

14. Install the gasket (96) on the back side (sheave housing side) of the 

Tower. See figure 116. 

15. Locate the SAE mounting plate (93) on the guide bolts. Similar to figure 

106. 

Note: The hole for the fitting must be toward the outside. 

16. Carefully tap the SAE plate down tight against the gasket. Similar to 

figure 107. 

17. Install 5 hex head capscrews (94) with copper washers (95) to secure 

the plate to the housing. Similar to figure 108. Torque the capscrews 

to 48.8 Nm. (36 lb. ft.). 


Do not install the copper washer and hex head capscrew nearest 

the hole for the fitting until after the fitting is installed. The head of 

the capscrew will interfere with the fitting as is rotated into the 

hole. Similar to illustrations in figure 109. 

18. Install the pipe fitting in the hole. Similar to figure 109. 

Idler gear 

teeth 

Driven gear 

teeth 

19. Install the last hex head capscrew (94) with copper washer (95). Similar 

to figure 109. Torque the capscrew to 48.8 Nm. (36 lb. ft.) 



20. Install the cover (97) with gasket (96) on the plate. Install 4 hex head 

capscrews (98) to secure the cover to the SAE mounting plate (93). 

Similar to figure 110. Torque the capscrews to the proper specifications 



Tower #2 


Note: Do not install the pump (109) at this time. It will be installed 

later. 

21. Assemble the components of Tower #2. Follow the instructions as 

previously described in steps 1 through 20 for the first pump tower. 

See figures 102 through 117. 

143

Assembly 

Assemble the Control Valve Assembly 

144 


Position the HPTO with the towers and control valve area up. 


1. If it was removed, install the ditch plate (131) onto the clutch housing 

with ditch plate gasket (142). See figures 118 & 119. Secure with 6 

socket head capscrews (130). Torque the capscrews to the proper 



Note: Be sure the gasket is properly aligned so no hole or port 

is restricted or covered. 

Ditch plate 

Figure 118. Install the ditch plate and gasket. 

Figure 119. Ditch plate and gasket installed. 

Ditch plate 

gasket 

Clutch 

housing 

Assembly 1020729 only: (Assembly 1021658-skip to step 9.) 

2. Install the hydraulic relief valve (124) and plug (126) in the center section 




of the control valve assembly. See figure 120. Tighten securely. 

Note: The hydraulic pressure will be adjusted later as described 

in the Installation section of this manual. 

For valve assembly 1020729 

Pipe Plug 

Plug 

Gasket 

o-ring 

Elbow 

Hydraulic 

Relief Valve 

Figure 120. Assemble the regulator section. (Assembly 1020709) 

3. Lubricate the o-ring on the elbow fitting (112) with an assembly grease. 

See figure 121. Install the fitting in the center section of the control valve 

assembly. Tighten securely. The fitting should point horizontally toward 

the right side (viewed from the rear) of the HPTO . 

Note: Be careful to prevent damage to the o-ring during 

assembly. 

4. Install the main regulator (center section) valve body (115) onto the ditch 

plate with gasket (133). See figure 121. Secure with 4 socket head 

capscrews (127). Torque the capscrews to the proper 

specifications given in Torque Values for Fasteners in Table 8 of 

the Installation section. 



145

Assembly 

146 

Capscrew 



See figure 121. Install the four socket head capscrews (127) 

into the ditch plate and install the gasket (133) on the plate aligned 

on the capscrews to assist in being sure the gasket is properly 

positioned and aligned. 

Center 

(main regulator) 

section 

Elbow fitting 

Gasket 

Ditch plate 

Figure 121. Install the elbow fitting and gasket on the valve body. 

5. Lubricate the o-rings of the two 3-way proportional valves (125) with an 

assembly grease. See figure 122. Install the proportional valves in the 

top section of the control valve assembly. Use a twisting motion while 

pushing each valve into the bore. Position the connectors horizontally, 

pointing directly opposite each other. Secure with lock plate (122) and 

hex head capscrew (123). Torque the capscrews to the proper 



Note: Be careful to prevent damage to the o-rings during 

assembly. 

Pipe Plug 

Cartridge 

Plug o-rings 

Pipe Plug 

Gasket 

Figure 122. Install the 3-way proportional valves. 

Pipe Plug 

3-way Proportional 

Valve o-rings 



6. Lubricate the o-rings of the valve cartridge plug (128) with an assembly 

grease. Install the cartridge in the top section of the control valve 

assembly. 



assembly. 

7. Install the (top section) valve body (134) onto the center (main regulator) 

valve body section with gasket (114). See figure 123. Secure with 6 

hex head capscrews (113). Torque the capscrews to the proper 

specifications given in Torque Values for Fasteners in Table 8 of the 

Installation section. 




See figure 123. Install the six socket head capscrews (113) into 

the valve body and install the gasket (114) on the plate aligned 

on the capscrews to assist in being sure the gasket is properly 

positioned and aligned. 

Capscrew 

Top valve 

section 

Figure 123. Install the top valve body and gasket. 

3-way 

proportional 

valves 

Gasket 

Center 

(main regulator) 

section 

8. Install the remaining pipe plugs, in the control valve assembly. See figure 

124. 

147

Assembly 

148 

156 

Pipe plug 

Lock plate 

Proportional 

valve 

Hydraulic 

relief valve 

Figure 124. Install the remaining plugs. (Early design) 


Valve assembly 1021658 only: 

9. Install the filter (142) in the end of the body (115). See figure 125. 

155 

154 

153 

152 151 

150 149 

Figure 125. Assemble the regulator section. (Assembly 1021658) 

10. Install the valve (143) in the hole in the body. 

148 

147 

157 142 

Top section 

Center 

section (main 

regulator) 

Ditch plate 

11. While holding the filter and valve in the body install the cover (145) with 

gasket (144) and secure with four hex head capscrews (146). Torque 

the capscrews to the proper specifications given in Torque Values 

for Fasteners in Table 8 of the Installation section. 

12. Install the o-ring (151) on the piston and thread the piston into the cover 

(153). Place the inner spring (150), outer spring (149), washer (148) on 

the spool (147). See figure 126. 

115 

158 

144 

145 

146 

143 




Cover Spool Springs Piston Jam Nut Cap 

Figure 126. Pressure regulator (Used with assembly 1021658) 

13. Lubricate the o-ring with oil or an assembly lubricant and install the piston 

unit into the body. Secure with four hex head capscrews (154). Torque 

the capscrews to the proper specifications given in Torque Values 

for Fasteners in Table 8 of the Installation section. 

Note: Be careful to prevent damage to the o-ring during 

assembly. 

14. Install the jam nut (155) and hand-tighten it against the cover. Install the 

cap (156) and hand-tighten. 

Note: The hydraulic pressure will be adjusted later as described 

in the Installation section of this manual. 

15. Lubricate the o-rings of the two 3-way proportional valves (125) with an 

assembly grease. See figure 126. Install the proportional valves in the 

top section of the control valve assembly. Use a twisting motion while 

pushing each valve into the bore. Position the connectors horizontally, 

pointing directly opposite each other. Secure with lock plate (122) and 

hex head capscrew (123). Torque the capscrews to the proper 




assembly. 

149

Assembly 

150 

159 

113 

116 

134 


Figure 127. Assemble the top valve section. (Used with assembly 

1021658.) 

16. Install the (top section) valve body onto the center (main regulator) valve 

body section with gasket (114) between the sections. See figures 126 

& 127. Then, install both sections on the ditch plate with gasket (133) 

between the center section and the ditch plate. 

Note: Be sure both gaskets are properly aligned so no hole or 

port is restricted or covered. 


Install the six socket head capscrews (113) through the top valve 

body and install the gasket (114) aligned on the capscrews to 

assist in being sure the gaskets are properly positioned and 

aligned. Then install the center section on the capscrews followed 

by the gasket (133). Finally, place the whole unit on the ditch 

plate. 

17. Lubricate the o-rings of the directional control valve (159) with an 

assembly grease. Install the valve in the top section of the control valve 

assembly. Torque the valve to 36 N-m (26.5 ft.-lbs.) 


assembly. 

18. Install the remaining pipe plugs, in the control valve assembly. See figure 

127. 

122 

123 

125 

118 

114 

125 



Install the Speed Sensor Pickups 


Output speed sensor 

1. View into the output speed sensor in the hole in the side of the clutch 

housing just below the control valve. See figure 128. Rotate the main 

output shaft so a tooth on the O.D. of the gear and ring assembly (9) is 

directly aligned with the center of the hole. Install the speed sensor until 

it just touches the tooth. Then back it out as specified in the Description 

and Specification section of this manual. 

Double 

lock nuts 

Figure 128. Install the output speed sensor. 


Speed 

sensor 

2. Mark the exact location of the speed sensor. Then back it out an additional 

6 turns so thread sealant MA908 can be applied to the threads. 

3. Apply thread sealant MA908 to the threads. Thread the sensor back to 

the original position. 

4. Tighten the lock nut closest to the housing. Torque the nut to the 

specifications contained in the Description and Specification section 

of this manual. Then tighten the second lock nut against the first and 

torque it as specified in the Description and Specification section 

of this manual. 

151

Assembly 

152 

Input speed sensor 


5. View into the driven gear speed sensor in the hole in the side of tower 

#2. See figure 129. Rotate the driven gear so a tooth is directly aligned 

with the center of the hole. Install the speed sensor until it just touches 

the tooth. Then back it out as specified in the Description and 

Specification section of this manual. 

Tower 

#2 

Double 

lock nuts 

Figure 129. Install the input speed sensor. 

Speed 

sensor 

6. Mark the exact location of the speed sensor. Then back it out an additional 

6 turns so thread sealant MA908 can be applied to the threads. 

7. Apply thread sealant MA908 to the threads. Thread the sensor back to 

the original position. 

8. Tighten the lock nut closest to the housing. Torque the capscrews to the 

proper specifications given in the Description and Specifications section 

of this manual. Then tighten the second lock nut against the first and 

torque the capscrews to the proper specifications given in the 




Install the Pump 


1. If used, install the pump (109), meshing the splines of the pump and 

driven gear (83). Position the pump with the long flange section at the 

bottom. 

2. Secure the pump to the front housing using 4 hex head capscrews (82). 





153

Assembly 

Plumbing 

154 


Double 

lock nuts 


1. The various applications may use slightly different pump and gear tower 

locations, which result in slightly different plumbing configurations. Refer 

to the engineering drawings at the back of this manual and the typical 

plumbing illustrations near the back of this section for exact plumbing 

components and configurations. See figures 130 through 134. 

Note: The illustrations below show various fittings, plumbing 

configurations, and components to complete the assembly 

of the HPTO. These illustrations are provided as a 

convenience to clarify questions not specifically covered 

in this manual. 

It is likely that the HPTO you are working on is not the 

same model or BOM illustrated. Refer to the engineering 

drawings for your specific unit. 

Figure 130. Typical installation of components. 


Ditch plate 







Speed 

sensor 

Speed 

sensor 

Speed 

sensor 

155

Assembly 

HPTO Series Parts Identification List 

156 


Item Description Qty. Item Description Qty. 

1 Coupling, flexible 1 

2 Housing, coupling 1 

3 Plug, pipe 1-11 1/2 NPTF 1 

4 Capscrew, hex. hd. 7/16”-14 x 1.38” 12 

5 Capscrew, hex. hd. 1/2”-13 x 1.25” 13 

6 Housing, front 1 

7 Seal, radial 1 

8 Bearing, ball 1 

9 Gear & drive ring assy. 1 

10 Ring, snap, internal (service) 1 

11 Bearing, cylindrical 1 

12 Shaft 1 

13 Plug, pipe, shaft 1 

14 Plug, ball, shaft 2 

15 Ring, external snap, shaft 1 

16 Hub, clutch 1 

17 Plate, steel, clutch 8 

18 Plate, friction, clutch 8 

19 Ring, seal 2 

20 Carrier, piston 1 


22 Piston, clutch 1 

23 Spring 9 

24 O-ring, plate 1 

25 Ring, internal snap, piston 1 

26 Plate, back 1 

27 Pin, dowel, .157” x 1.0” 4 

28 Plate, friction, clutch 1 

29 Pin, anti-rotation, piston 4 

30 O-ring, shaft 1 



33 Pin, dowel, 1/4 x .38 1 


35 Ring, spacer 1 

36 Spacer, bearing 1 

37 Housing, clutch 1 

38 Bearing, double cup assy (Model I) 1 

38 Bearing, spherical (Model S) 1 

39 Plug, pipe, clutch housing 1 

40 Gasket, spacer 2 

41 Spacer 1 

42 Pin, dowel, 12mm. x 24mm. 2 

43 Capscrew, hex. hd. 1/2” - 13 x 1.75 6 

44 Retainer, bearing, front bearing 1 

45 Seal, radial 1 

46 Carrier, bearing (Model I) 1 

46 Housing, belt, sheave (Model S) 1 


48 Plug, pipe, clutch housing 1 

49 Fitting, grease 1 

50 Retainer, bearing, rear bearing 1 

51 Bearing, spherical 1 

52 Ring, bearing 1 

53 Screw, hex. hd. M12 x 1.75 6 

54 Plug, pipe, 1/8 1 

55 Key, output 1 

56 Gasket 1 

57 Shims A/R 

58 Gear, idler 1 

59 Washer, idler gear 1 

60 Capscrew, hex. hd. 3/8”-24 x 5/8” 4 

61 Washer, idler gear 1 

62 Capscrew, hex. hd. 3/8”-24 x 5/8” 4 

63 Bearing, Roller 1 

64 Ring, snap, bearing carrier 1 

65 Carrier, bearing 1 

66 Pin, dowel, 3/8” x .250” 1 

67 Plug, pipe, 1/4 1 

68 Capscrew, 12 pt. 3/8”-11 x 3.50” 3 

69 Gasket, plate 1 

70 Plate, SAE mounting 1 


72 Washer, copper 6 

73 Gasket, cover 1 

74 Cover 1 

75 Capscrew, hex. hd. 2” - 13 x 1.0 4 

76 Bearing, Ball 1 









HPTO Parts Identification List 

Item Description Qty. Item Description Qty. 

83 Gear, driven 1 


85 Plug, pipe 1 

86 Manifold 1 

87 Nipple, pipe 1 






93 Cover 1 

94 Cover 1 

95 Capscrew, hex. hd. 2” - 13 x 1.0 4 








103 Gear, driven 1 

104 Cover 1 


106 Fitting, elbow 1 

107 Fitting, elbow 1 

108 Breather 1 

109 Pump 1 

110 Washer, bearing lock 1 

111 Nut, bearing lock 1 

112 Fitting 1-1/16-20 to M27 X 2 elbow 1 

113 Capscrew, hex hd. M10 X 1.5 X 70.0 6 

114 Gasket, cartridge valve body 1 

115 Body, valve, main regulator 1 

116 Plug, o-ring M12 X 1.5 1 

117 Plug, o-ring M12 X 1.5 1 

118 Plug, o-ring M12 X 1.5 1 

119 O-ring 1 

120 O-ring 1 


121 O-ring 1 

122 Plate, lock 1 

123 Capscrew, socket hd. M6 X 1.0 X 16.0 1 

124 Valve, cartridge, hydraulic relief 1 

125 Valve assy. 3-way proportional valve 2 

126 Plug 1 

127 Capscrew, socket hd. M10 X 1.5 X 50.0 4 

128 Valve, cartridge, plug 1 

129 Plug, pipe, valve body 1 

130 Capscrew, socket hd. 3/8”-16 6 

131 Plate, ditch 1 

132 O-ring, carrier 1 

133 Gasket, ditch plate 1 

134 Body, valve 1 

135 Cover, inspection 1 

136 Screw, cover, M6 hex. hd. 4 

137 Gasket, ditch plate-to Clutch Hsg. 1 

138 Plug, pipe, 1/4 1 

139 Reducer, pipe 1 

140 Housing Spacer 1 

141 Dowel Pin 2 

142 Filter 1 

143 Valve 1 

144 Gasket 1 

145 Cover 1 

146 Capscrew, hex hd. 4 

147 Spool 1 

148 Washer 1 

149 Spring, outer 1 

150 Spring, inner 1 

151 O-ring, piston 1 

152 Piston 1 

153 Cover 1 

154 Capscrew, hex hd. 4 

155 Nut, hex 1 

156 Cap 1 

157 Plug 1 

158 Plug 1 

157

Assembly 

158 


Models HP300I & HP600I Cross-Section View 

Gear Tower Area 

(see following pages) 

Front 

Bearing Area 


2 

1 

5 

10 

9 

135 136 

Clutch 

Area 

(see following 

pages) 

6 56 4 

GP Control 

Valve Area 


pages) 

37 

Rear Bearing Area 


Note: Some parts not shown 


55 

12


Models HP300S & HP600S Cross-Section View 

Gear Tower Area 


Front 

Bearing 

Area 


pages) 

2 

1 

5 

10 

3 

9 


Clutch 

Area 


pages) 

GP Control 

Valve Area 


pages) 

135 136 6 56 4 37 46 42 

Pin 

Sheave Housing 

Front Bearing Area 


47 

Sheave Housing 

Output Bearing Area 


Note: Some parts not shown 

12 

55 

159

Assembly 

160 


Models HP300S & HP600S Sheave Housing Front Bearing Area 

Exploded View 

39 

42 

37 

48 

141 

40 

34 

41 

40 

42 

12 

140 

141 

33 

38 

Note: Typical unit illustrated. 

Approximate area shown. 

44 

35 


36 

46 

45 

43


Models HP300S & HP600S Sheave Housing Output Bearing Area 

Exloded View 

12 


54 

46 

51 



52 

49 

50 

53 

161

Assembly 

Models HP300I, HP600I, Rear Bearing Area Exploded View 

162 

34 

37 

39 

12 

55 

38 

110 




111 

132 


47 

46 

45


Models HP300I, HP600I, HP300S & HP600S Clutch Area Exploded 

View 

22 

29 

9 

19 


11 

21 

15 

30 

31 

16 

32 

18 

20 

19 

26 

17 

24 

23 

25 



28 

27 

163

Assembly 

164 


Models HP300I, HP600I, HP300S & HP600S Front Bearing Area 

Exploded View 

Not shown 

(In Tower) 

108 Breather 

138 Plug, pipe 

139 Reducer, pipe 

6 

3 

85 

7 

8 

9 




11 

12


Models HP300I, HP600I, HP300S & HP600S Idler Gear Area 

Exploded View 

67 

68 


64 

66 

65 

57 

62 

61 

63 

58 



60 

59 

165

Assembly 

166 


Models HP300I, HP600I, HP300S & HP600S Tower #1 Area Exploded 

View 

71 

72 

75 

106 Elbow fitting 

not shown 

74 

73 

70 

69 

6 

84 

83 

76 

87 

77 

86 

6 

78 


81 

80 


94 

79 

82


Models HP300I, HP600I, HP300S & HP600S Tower #2 Area Exploded 

View 

102 

103 

75 


74 

104 

101 

100 

107 Elbow fitting 

not shown 

6 

87 

77 

86 

97 

98 

96 

78 

80 

79 

81 



109 

6 

91 Cover not shown. 

(NOt used if a pump 

is used in this 

location 

82 

167

Assembly 

168 


Models HP300I, HP600I, HP300S & HP600S GP Control Valve Area 

Illustration 


51 

Lock Plate 

51 

113 122 123 113 

51 

51 

51 

124 

127 

125 

112 

124 

126 

112 

116 

133 

131 

124 

119 

120 

125 

113 

121 

113 

126 

116 

112 

112 


113 

128 

130 

128 

130 

117 

129 

134 114 

115 

134 

114 

115 

143 

129 




Exploded View - (Valve assembly 1020729 is illustrated) 

116 

128 

134 

118 

114 

127 

129 

115 

126 

133 

137 


125 

113 

117 

122 

123 

112 

124 

130 

131 


125 

169

Assembly 

170 



Exploded View - (Valve assembly 1021658 is illustrated) 

156 

154 

126 

155 

153 

152 

151 

113 

150 

116 

149 

148 

147 

134 

115 

122 

123 


125 

118 

114 

125 

157 142 

158 

144 

145 

146 

143 



Models HP300I, HP600I, HP300S & HP600S Pipes and Fittings 

Illustrations 



171

Assembly 

172 


Models HP300I, HP600I, HP300S & HP600S Pipes and Fittings 

Illustrations 

Note: Typical units illustrated. 




Troubleshooting 


Troubleshooting of GP Control Valve with Electronic Interface 

The HPTO is one part of a complete power package. Problems in the input 

power system or the output power delivery components can cause problems to 

develop in the HPTO. It is therefore important that the entire power package 

be considered when problems are encountered. 

Electronic Interface LED Indicators 

The electronic interface control modules have one green and two red LED 

indicator lights. The green power light is illuminated whenever the input power 

is more than 9.0 volts. 

The following table lists the reasons for the various conditions where lights are 

illuminated. This should guide in troubleshooting problems. See the wiring 

schematics in the Installation Section. 

Troubleshooting Tables begin on the next page. 

Table 14. LED Light Status 

Light Status Profile Generator 

(Non trolling) 

Green light on Supply Voltage > 9.0 Volts 

Red light on Valve coil commanded on 

One red light flashing Open circuit in an energized 

valve coil circuit, or Valve coil 

leads shorted together, or Low 

coil current 

Both red lights flashing 

simultaneously 

Both red lights flashing 

alternately 

Not applicable 

Either or both speed signals 

missing 

173


174 

Table 15. Troubleshooting Chart --- GP Valve Equipped HPTO 

Symptom Cause Remedy 

1. Low main oil pressure 1-1 Partially clogged oil 

strainer 

2. No oil pressure, or erratic 

low pressure at control 

valve. 

1-2 Contamination on Pilot 

Relief Val ve seat. 

1-3 Contamination in Main 

Valve Cartridge 

1-4 Broken piston rings on 

clutch shaft(s). 

1-5 Damaged or worn oil pump 

assembly. 


1-1 Remove and clean oil 

strainer. 

1-2 Disassemble the Pilot 

Relief Valve and clean. 

Service the transmission 

oil filter. 

1-3 Clean or replace the Main 

Val ve Cartridge, and 

service the transmission 

oil filter. 

1-4 Remove the collector and 

inspect piston rings. 

1-5 Replace damaged or worn 

oil pump assembly (pump 

is not serviceable). 

1-6 Engine idle speed too low. 1-6 Raise engine speed. 

2-1 Oil pump suction strainer 

plugged. 

2-1 Remove and clean 

strainer. 

2-2 Oil level low. 2-2 Check oil level and 

correct. 

2-3 Air leak on suction side of 

pump. 

2-3 Correct cause of air leak. 

2-4 Pump dri ve broken. 2-4 Disassemble and repair as 

required. 

2-5 Pilot Relief Valve or Main 

Regulating Val ve stuck in 

open position 

2-6 Remove, disassemble, 

clean and repair the Pilot 

Relief Valve. Remove, 

clean, or replace the Main 

Regulating val ve. This 

valve cannot be 

disassembled. 

2-6 Oil pump defective 2-7 Replace oil pump. 

2-7 Leaking heat exchanger 

has caused oil to be lost 

externally. 

2-7 Replace heat exchanger 





Table 15. Troubleshooting Chart (continued)--- GP Valve Equipped HPTO 


1. Low main oil pressure 1-1 

2. 

No oil pressure, or 

erratic low pressure at 

control valve. 

1-2 

1-3 

1-4 

1-5 

1-6 

2-1 

Partially clogged oil 

strainer 

Contamination on Pilot 

Relief Val ve seat. 

Contamination in Main 

Valve Cartridge 

Broken piston rings on 

clutch shaft(s). 

Damaged or worn oil 

pump assembly. 

Engine idle speed too 

low. 

Oil pump suction strainer 

plugged. 

1-1 

1-2 

1-3 

1-4 

1-5 

Remove and clean oil 

strainer. 

Disassemble the Pilot 

Relief Valve and clean. 

Service the transmission 

oil filter. 

Clean or replace the 

Main Valve Cartridge, 

and service the 

transmission oil filter. 

Remove the collector 

and inspect piston rings. 

Replace damaged or 

worn oil pump assembly 

(pump is not 

serviceable). 

1-6 Raise engine speed. 

2-1 

2-2 Oil level low. 2-2 

2-3 

Air leak on suction side of 

pump. 

2-4 Pump dri ve broken. 2-4 

2-5 

Pilot Relief Valve or Main 

Regulating Val ve stuck in 

open position 

Remove and clean 

strainer. 

Check oil le vel and 

correct. 

2-3 Correct cause of air leak. 

2-6 

Disassemble and repair 

as required. 

Remove, disassemble, 

clean and repair the Pilot 

Relief Valve. Remove, 

clean, or replace the 

Main Regulating valve. 

This valve cannot be 

disassembled. 

2-6 Oil pump defective 2-7 Replace oil pump. 

2-7 

Leaking heat exchanger 

has caused oil to be lost 

over board. 

2-7 Replace heat exchanger 

175


176 


6. No neutral. 6-1 Clutch plates warped. 6-1 

7. Harsh engagement. 7-1 

7-2 

8. Low lube oil pressure. 8-1 

9. 

10. 

Faulty Proportional 

Valve. 

Profile Generator 

defective or out of 

adjustment. 

7-1 

7-2 


Table 15. Troubleshooting Chart (continued)--- GP Valve Equipped HPTO 

Oil spilling out of 

breather. 

Low Clutch Apply 

Pressure 

8-1 

8-3 

8-4 

Pump flow output too 

low. 

Pump suction strainer 

plugged. 

Air leak on suction side 

of pump. 

Lube relief valve 

malfunction. 

Remove clutch plates. 

Overhaul unit. 

Replace Proportional 

Valve. 

Replace Profile 

Generator. Adjust if 

proper equipment is 

available. 

8-1 Replace pump. 

8-2 

8-3 

8-4 

8-5 Broken piston rings. 8-5 

Remove, clean, inspect, 

and install the suction 

screen. 

Inspect and correct 

cause of suction leaks. 

Remove and clean or 

replace parts as 

necessary. 

Replace damaged 

piston rings. 

9-1 Oil level too high. 9-1 Adjust oil level. 

9-2 Wrong type of oil. 9-2 Draw and refill with 

recommended oil. 

10-1 Low Main Pressure 

10-2 

Defective Proportional 

Valve. 

10-1 See Paragraph 1. 

10-2 

Replace Proportional 

Valve 


Twin Disc, Incorporated Engineering Drawings 

The engineering drawings included are listed below. 


Engineering Drawings 

Note: All part numbers listed in the following engineering 

drawings are for reference only. Please refer to your bill 

of material for part numbers specific to your model. 

� Twin Disc Hydraulic Power Take-off Cutaway 

� 1020668G HP300I: Sheet 2 of 3 

� 1020668G HP300I: Sheet 3 of 3 

� 1020668B HP300S: Sheet 2 of 3 

� 1020668B HP300S: Sheet 3 of 3 

� 1020668F HP600I: Sheet 2 of 3 

� 1020668F HP600I: Sheet 3 of 3 

� 1020668C HP600S: Sheet 2 of 3 

� 1020668C HP600S: Sheet 3 of 3 

� 1020696 Control Valve Assembly 

� 1021658 Control Valve Assembly 

� 1020686 HPTO Control Module 

� 1021292 Sheet 1 of 3 HPTO Plumbing 



� 1021295 Piping Diagram 

� X216923BU Gear Group (Sae C) 

� X216923BV Gear Group (Sae B) 

� X216923BX Gear Group (Sae B & C) 

Contact your 

Authorized Twin Disc Dealer 

for the latest BOM and 

engineering drawings. 

177

Engineering Drawings 

Twin Disc Hydraulic Power Take-Off Cut-away Illustration 

178 



SEE NOTE "B" 

SEE NOTE "C" 

PLUG, MA1038B 

MAIN PRESSURE CHECK 

M12x1.5 THD. CONFORMS 

TO ISO 6149 

VALVE, SEE CHART (TORQUE TO 36 N-m) 

(1021000A SHOWN) 

SCREW, MA960A (4) 

CAP, 1002144 

SEE NOTE "D" 

COVER, 1021661 

NUT, 1002145 

PORT "A" 

F 

CL 

LUBE (IP) 

SUMP 

SUMP 

BODY, 1020519 

PLUG, SEE CHART 

OPTIONAL INLET PORT 


TO ISO 6149 

SPOOL, 1021660 

CL 

BOTTOM VIEW 

SCALE = HALF 

SPRING(S) 

SEE CHART 

RING, A2916LV 

PISTON, 1020939A 

MAIN (CP) 

PORT "B" 

E 

SCREW, MA961X (6) 

PORT "B" 

WASHER, A2782AV 

B 

A2 ECN12561 7-28-04 

A B3 ECN12537 6-28-04 

REV SHEET ZONE CH. NO. 

DATE 

"O"RING, A2916JT (2) 

REV 

PORT "A" 

VALVE, 1020942 

BODY, 1021659 

SEE CHART 

STAMP VALVE ASSEMBLY 

IDENTIFIER HERE 

SHEET 

PLATE, 1018175 

UNLESS OTHERWISE SPECIFIED 

MACHINED DIMENSIONS 

X. 

±0.75 

X.X 

±0.25 

X.XX ±0.13 

ALL ANGULAR TOLERANCES ±1° 

GEOMETRIC TOLERANCING 

PER ASME Y14.5M 1994 

SCREW, MA1100B 

PROPORTIONAL VALVE, 

SEE CHART (2) 

SEE NOTE "A" 

PLUG, MA1038B (2) 

CLUTCH PRESSURE PORT 


TO ISO 6149 

GASKET, 1020531 

VALVE VALVE 

ASSEMBLY ASSEMBLY 

PART NO. IDENTIFIER 

1021658A 

1021658B 

1021658C 

1021658D 

1021658E 

1021658F 

1021658G 

1021658H 

1021658J 

FILTER, P10786 

GASKET, 1021663 

COVER, 1021662 

kg 

SCREW, MA960M (4) 

A 

BOM PRESSURE 

kPa 

(psi) 

(230-260) 

2205-2760 

(320-400) 

1795-2205 

(260-320) 

1585-1795 

(230-260) 

2205-2760 

(320-400) 

1585-1795 

(230-260) 

1585-1795 

(230-260) 

1585-1795 

(230-260) 

WEIGHT WR FIRST USE 

2 

ASSY. 

N m 

MODEL 

2 

1020391 

MG-5222DC 

NOTICE! THIS PRINT CONTAINS PROPIETARY INFORMATION AND IS NOT TO BE USED IN ANY 

MANNER DETRIMENTAL TO THE INTEREST OF 

TWIN DISC, INCORPORATE 

METRIC 

NOTES: 

A. PROPORTIONAL CONTROL VALVE OPERATION. 

1. WARNING DO NOT CONNECT VALVE COIL DIRECTLY 

TO BATTERY/POWER SUPPLY VOLTAGE. 

2. OPERATION TO BE PERFORMED WITH ONLY TWIN DISC 

CONTROL SYSTEMS OR MODULES. 

B. MANUAL DIRECTIONAL CONTROL VALVE OPERATION. 

1. WITH MANUAL DIRECTIONAL CONTROL VALVE IN 

CENTERED POSITION, PUSH TO ENGAGE PORT "A". 

2. WITH MANUAL DIRECTIONAL CONTROL VALVE IN 

CENTERED POSITION, PULL TO ENGAGE PORT "B". 

C. MANUAL DIRECTIONAL CONTROL VALVE MODE SWITCH. 

1. SWITCH IS NORMALLY CLOSED WHEN MANUAL DIRECTIONAL 

CONTROL VALVE IS IN THE CENTERED POSITION AND 

OPEN WHEN LEVER IS ACTUATED FROM CENTERED POSITION. 

2. CURRENT = 20 AMPS MAX. 

3. FOR WIRING SCHEMATIC, REFER TO CONTROL MODULE 

DRAWING. 

D. PRESSURE REGULATOR ADJUSTMENT. 

1. REMOVE 1002144 CAP AND LOOSEN 1002145 NUT. 

2. CLOCKWISE ROTATION OF 1020939A PISTON INCREASES 

PRESSURE. COUNTER CLOCKWISE DECREASES PRESSURE. 

3. LOCK PISTON IN PLACE USING JAM NUT AND REPLACE CAP. 

E. REFER TO MARINE TRANSMISSION ASSEMBLY DRAWING OR 

BILL OF MATERIAL FOR VALVE MOUNTING AND SCREWS. 

F. APPLY ANAEROBIC SEALANT MEETING M2828 REQUIREMENTS 

AROUND CORE PLUG, JUST BEFORE FINAL ASSEMBLY. REFER TO 

S774 FOR FURTHER INFORMATION. 

G. MODIFICATION KIT TO UPGRADE EXISTING 1020729/1020696 

SERIES VALVE ASSEMBLIES TO 1021658 SERIES VALVE ASSEMBLY. 

SPRING(S) VALVE SENSOR PLUG PLUG 

B 43111 1021000A 

C 43112 

201341ZC 

201341ZE 1021000A NONE M2051S MA1038E NONE 1020520 

D 43195 

201341ZC 

201341ZD 

1021000A 1016122A NONE MA1038E NONE 1020520 

E 43196 

201341ZC 1021000A1016122A 

NONE MA1038E NONE 1018528 

F 43197 

201341ZC 

201341ZE 1021000A1016122A 

NONE MA1038E NONE 1020520 

G 43198 

201341ZC 1020542 NONE M2051S MA1038E M1945E 

PORT "A" 

1018528 

H 43199 

201341ZC 1021000A NONE M2051S MA1185A NONE 1018528 

J 43200 

201341ZC 1020542 NONE M2051S MA1053Q NONE 1018528 

1585-1795 

A 43110 1795-2205 

(260-320) 

201341ZC 

201341ZD 1021000A NONE M2051S MA1038E NONE 1020520 

201341ZC NONE M2051S MA1038E NONE 1018528 

THIRD ANGLE 

PROJECTION 

MATERIAL HEAT TREAT 

ZONE CH. NO. 

DATE 

THIS NOTICE IS NOT INTENDED TO NULLIFY OR LIMIT RIGHTS GRANTED TO THE U.S. 

GOVERNMENT OR OTHERS BY CONTRACT. 

DWG SHT. 

WTW SIZE A1 1 of 1 

REV 

B 

D C B A 

SIMILAR TO 

NAME 

CORE 

PLUG PROPORTIONAL 

SEE NOTE VALVE 

"F" 

VALVE ASS'Y. 

DATE 

SCALE 

DRN. 

CHK. 

APPD. 

5-04-04 

FULL 

D. MEYERS 

ALC 

B 

B 

MODIFICATION 

KIT 

SEE NOTE "G" 

K1417 

K1418 

K1420 

K1417 

K1418 

K1420 

K1419 

K1418 

K1418 

TWIN DISC 

I N C O R P O R A T E D 

RACINE, WI 53403 - USA 

1021658 

5 

4 

3 

2 

1

OIL SPECIFICATIONS: Use only SAE-API service class CD or CC engine oil certified 

to meet Caterpillar TO-2 transmission oil specification and/or Allison type C-4 

transmission fluid. Oil viscosity is dependent on ambient temperature and resulting 

operating temperatures. See manual for recommendations. Multi-viscosity oils can be 

used, but require Twin Disc approval. 

SUMP: Customer supplied. Minimum size, 8 gallons. Use baffles to allow return oil to 

settle away from suction port. Recommended to be mounted below HPTO and allow for 

gravity drain from 1-1/2" drain ports. If the sump cannot be mounted below the HPTO, a 

scavenge pump that is 1.5 – 2 times the size of the charge pump must be used. Three 

drain ports are provided under the HPTO. Connecting all 3 ports may be required if 

drainage hoses are to long and tightly bent. 

Warning: Insufficient drainage will cause unit to overheat and oil will flow out from 

breather. 

FILTRATION: Customer supplied. The HPTO contains electronically controlled 

proportional pressure valves, thus filtration must meet the following criteria: Beta 

removal efficiency rating 2/20/75 for particle sizes 5micro/13micro/16micro. A typical 

filter element should say "5 micro nominal" or "16 micro absolute". 

COOLING REQUIREMENTS: Customer supplied, air to oil cooling is typical. 

-Minimum oil temperature at start-up: -40F. 

-Oil temperature at steady operating conditions: 100F-185F. 

- Recommended inlet temperature of H.E. to be 170F. 

- Recommended outlet temperature of H.E. to be 150F. 

-Oil flow to H.E. from HPTO: Pump specific (0.0085 GAL/REV theoretical for the 

standard Twin Disc pump) 

- The equivalent heat generation of the HPTO is 28000 BTU/hr continuous. Due to 

deterioration in cooling capacity in a dust-heavy environment; Twin Disc recommends 

that a larger heat exchanger be considered when feasible. 

-Peak oil pressure at H.E.: 265PSI. 

CHARGE PUMP SPECIFICATIONS: Twin Disc or customer supplied. 15 GPM 

maximum flow required. Oil flow of 8.5 GPM is required at 1000 rpm. Pump rotation is 

CW on output side, or CCW when mounted on engine side. 

MAINTENANCE REQUIREMENTS: All bearings within the main unit are oil 

lubricated. The output bearing of the straddle bearing housing unit is grease lubricated. 

Grease is to have operating temperature suitable up to 275F continuous use. NLGI grades 

0,1, or 2 are acceptable. Recommended greases would be Mobilgrease XHP 222, 

Mobilgrease CM-S, Mobilux EP-2 or equivalent. Add 1cc Every 10 hours. 

HOSE TYPE: Hoses must meet SAE517 specification for 100R17 or similar type for 

hydraulic applications. 

FITTINGS: Fittings selected must meet SAE J514, SAE J476, J518 standards.

#1021542 0804 

TWIN DISC, INCORPORATED RACINE, WISCONSIN 53403, U.S.A. 262-638-4000/262-638-4482 (FAX) WWW.TWINDISC.COM

Twin Disc HP 300, 600 service manual - Morbark

Create successful ePaper yourself

Delete template?

Save as template?