1926-1984 Vintage Models - S&S Cycle

S e ction 5:
S&S ®
Parts for
Twin Cam 96 /103
2007-2013
Parts for
Twin Cam 88 ®
1999-2006
5-Speed Transmission Case
for 1965-'85 4-Speed Big Twins
S&S 4 to 5-speed transmission cases are designed to convert 4-speed big twin frames with 1965-
’85 shovelhead style drivelines and chain final drives to 5-speed transmission (see notes below).
Includes the shift lever adjustment screw, shifter shaft guide, and all studs and dowel pins required
for assembly. Studs and dowel pins are installed. Accepts most OEM and aftermarket 5-speed style
trap doors, bearings, seals, and other parts designed for 1985-’99 big twin 5-speed transmissions.
The OEM trap door will require minor modification for use with this case. All modifications are
explained in the instructions. Main and counter shaft bearings and seals are not included.
1926-1984 Vintage Models
Parts for
Evolution ®
1984-1999
Parts for
Sportster ® & Buell ®
1986-2013
Parts for
Vintage Engines
1926-1984
Parts for
X-Wedge®
2007-2013
Parts for
Victory®
2003-2013
Racing
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PERFORMANCE
PARTS
Fitment
• 1965-’85 big twin 4-speed chassis
• Features and benefits
• Update 4-speed bikes to 5-speed transmission
• CNC machined from 356-T6 aluminum castings
• Accepts most OEM and aftermarket parts designed for 1985-’99
big twin 5-speed transmissions
• These items available for purchase separately –see next page
• CNC-machined billet trap door with bearings and required hardware
• Special battery box/starter brackets
• Shift linkage required for 4-speed FX and FL models
• Footpeg adapter kit required for FX
Kit Contents
• Required hardware
• Instructions
• Transmission case assembly
S&S® 4 TO 5-SPEED TRANSMISSION CASE KIT
Description Part #
Basic Case Assembly Kit 56-1051
MSRP
$532.95
Replacement parts on page 5-120
NOTES
The S&S 4 to 5-speed transmission case is not compatible with the factory Harley-Davidson®
primary belt drive used on 1980-’83 FXSB Sturgis models.
For applications that utilize an existing 4-speed driveline, a 1980 to early ‘84, 5-speed style
chain-drive mainshaft and 1980 to early ‘84 style main drive gear must be used. These parts
are compatible with the tapered I.D. clutch hub used on 4-speed big twins.
4 and 5-speed transmissions utilize the same 1:1 final drive ratio. As a result, the 5-speed
gear set will not alter engine RPM at highway speeds. The additional gear narrows the gap
between lower gears for improved acceleration and better performance in traffic.
This transmission case will fit earlier big twin frames. However, the engine sprocket shaft
must be of the type used in 1970-later big twin style engines. The transmission case itself is
compatible with H-D® secondary (rear) belt drive if the correct mainshaft, main drive gear,
inner primary cover, starter shaft, starter housing, and related parts are used. However, the
builder may encounter other obstacles when converting a motorcycle with chain final drive
to belt final drive.
The purchaser’s countershaft and shift fork shaft will require shortening.
A low contact-style countershaft gear must be used in this transmission case to match the
1980-’84 main drive gear required. Harley-Davidson® replaced low-contact gears with
high-contact gears on 1994 international big twin models and 1995 U.S. models. Low and
high contact gears may not be mixed.
S&S trap doors are of the 1987-’99 style. S&S recommends using this style trap door and
end cover with the "ball and ramp" clutch actuator. The strength of the earlier, lever-type
actuator is marginal for heavy clutch springs sometimes required in high-performance
applications.
Most 4-speed big twin style engines utilize transmission-driven mechanical speedometers.
This transmission case has no provision for speedometer drive, and must be used with a
wheel-driven speedometer and speedometer drive. The existing wheel may require
modification to accept the speedometer drive unit.
The clutch-actuator end of the 4-speed clutch cable is not compatible with the five-speed
type clutch actuator. Options are to replace the existing clutch lever with an 1987-’99 style
lever or purchase a custom cable with the correct ends from Barnett Tool and Engineering in
Ventura, California. (Phone: 805-642-9435)
5-82 Order toll free 866-244-2673