Manual Gearbox - 3 Synchro Internal Components
Manual Gearbox - 3 Synchro Internal Components
Manual Gearbox - 3 Synchro Internal Components
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<strong>Manual</strong> <strong>Gearbox</strong> - 4 <strong>Synchro</strong> <strong>Internal</strong> <strong>Components</strong><br />
No. Part No. Description Qty. Remarks No. Part No. Description Qty. Remarks<br />
The 4 <strong>Synchro</strong> <strong>Gearbox</strong><br />
1968 On<br />
Fortunately 4 synchro gearboxes are much easier to identify and classify than their 3 synchro<br />
predecessors (parts availability is considerably better, too, but not brilliant in some areas). The two<br />
main changes are the modification of gear shafts and several of the bearings in 1979, and A Plus gears.<br />
A Plus gears were pro gressively introduced, the bulk of models changing over around 1982. The y have<br />
a sharper tooth angle and different pitch making them quieter than the earlier gears, with which they<br />
are not interchangeable. A Plus gears may be identified by the presence of a circumferential groo ve in<br />
the centre of the teeth, plus flush machining on both sides of the final drive pinion.<br />
The following summaries help with identification and give you points to watch for when ordering par ts:<br />
DAM3092 SHAFT, 1st motion, 17 teeth 1 1979-82; not 1275 models.<br />
DAM3167 SHAFT, 1st motion, 18 teeth 1 1979-80; 1275 models.<br />
DAM4930 SHAFT, 1st motion, 17 teeth, A Plus type 1 1982 on; not 1990-96, 1275 (France).<br />
DAM6242 SHAFT, 1st motion, 16 teeth, A Plus type 1 1990-96, 1275 (France).<br />
16 22G2033 RING, baulk 1<br />
17 CHM172 BEARING, 1st/3rd motion shafts, 9/16” i.d.1 For 22G1093/22G1371 1st motion shafts.<br />
13H9513 BEARING, 1st/3rd motion shafts, 11/16” i.d.1 For all other 1st motion shafts .<br />
18 ADU7619 BEARING, 1st motion shaft 1 In gearbox case.<br />
19 22G850 CIRCLIP, bearing retaining 1 0.094-0.096" (2.39-2.44mm)<br />
22G851 CIRCLIP, bearing retaining 1 0.097-0.099" (2.46-2.51mm)<br />
For the 1st motion shaft bearing supporting the nose of the shaft in the flywheel housing, please see the<br />
‘Flywheel Housing and Clutch Cover’ section of the Somerford Mini Catalogue.<br />
1968-73 Saloon and Estate, 1968-75 Van and Pick Up<br />
Pre-A Plus gears. Direct/remote gearchange type reverse gear and mainshaft bearing retainer (four<br />
screw fitting). 9/16" dia. nose on 3rd motion shaft, two step layshaft, laygear takes two large bearings<br />
and one small bearing. Different ratios for 1275 models.<br />
1973-79 Saloon and Estate, 1975-79 Van and Pick Up<br />
Pre-A Plus gears. Rod gearchange type reverse gear and mainshaft bearing retainer (4 screw fitting).<br />
9/16" dia. nose on 3rd motion shaft, two step la yshaft,laygear takes two large bearings and one small<br />
bearing. Different ratios for 1275 models .<br />
1979-82<br />
Pre-A Plus gears (except for final drive pinion on 3.444:1 ratio models, which became A Plus in 1979).<br />
Rod gearchange type reverse gear and mainshaft bearing retainer (4 screw fitting). 11/16" dia. nose on<br />
3rd motion shaft, three step layshaft, laygear takes one large and one small bearing. Idler and 1st<br />
motion shaft drive gear ratios revised, idler gear bearings in gearbox case revised (diameter change).<br />
Different ratios for 1275 models.<br />
3rd Motion Shaft<br />
20 22G833 SHAFT, 3rd motion, 9/16" nose dia. 1 1968-79.<br />
DAM7484 SHAFT, 3rd motion, 11/16" nose dia. 1 1979 on.<br />
21 AAU1365 BEARING, 3rd motion shaft 1<br />
22 ADU4992 RING, spring, bearing retaining 1<br />
23 22A522 RETAINER, 3rd motion shaft bearing, 1 1968-73, Saloons and Estates;<br />
4 screw fixing, direct/remote change type 1968-75, Vans and Pick Ups.<br />
DAM1756 RETAINER, 3rd motion shaft bearing, 1 1973-84, Saloons and Estates;<br />
4 screw fixing, rod change type 1976-84, Vans and Pick Ups.<br />
24 DAM5996 RETAINER, 3rd motion shaft bearing, 1 1984 on.<br />
3 screw fixing, rod change type<br />
25 SH505071 SCREW, retainer to gearbox case 4/3 Qty. 4 for 22A522/DAM1756 retainers .<br />
26 DAM2377 LOCK TAB, screw 2/1 Qty. 2 for 22A522/DAM1756 retainers .<br />
27 DAM6047 LOCK TAB, screw 1 For DAM5996 retainer.<br />
28 2A3714 SHIM, retainer A/R 0.003" (0.076mm)<br />
2A3715 SHIM, retainer A/R 0.010" (0.254mm)<br />
1982 on<br />
A Plus gears. Rod gearchange type reverse gear and mainshaft bearing retainer (4 screw fitting<br />
reducing to 3 screw fitting in 1984). 11/16" dia. nose on 3rd motion shaft, three step layshaft, laygear<br />
takes one large and one small bearing. Different ratios for French 1275 models in the 1990s.<br />
Close ratio and straight cut close ratio gear sets are available for 4 synchro pre-A Plus and A Plus<br />
gearboxes, as special orders; please contact us for details. Similarly, contact us if you already have<br />
Special Tuning helical close ratio or straight cut close ratio gears and you require replacement parts.<br />
Reverse Idler Gear<br />
1 22G1034 REVERSE IDLER, 17/18 teeth, 1 1968-73, Saloons and Estates;<br />
direct/remote gearchange type<br />
1968-75, Vans and Pick Ups.<br />
22G1832 REVERSE IDLER, 17/18 teeth, 1 1973-79, Saloons and Estates;<br />
rod gearchange type<br />
1976-79, Vans and Pick Ups.<br />
TUB10020 REVERSE IDLER, 17/18 teeth, 1 1979 on.<br />
rod gearchange type<br />
2 TUJ10001 BUSH, reverse idler 1<br />
3 DAM8038 SHAFT, reverse idler 1<br />
Laygear<br />
4 22G927 LAYGEAR, 15/20/25/29 teeth 1 1968-79; 2 step layshaft, not 1275.<br />
22G1040 LAYGEAR, 15/20/25/29 teeth 1 1968-79; 2 step layshaft, 1275.<br />
5 DAM3169 LAYGEAR, 15/20/25/29 teeth 1 1979-82; 3 step layshaft, not 1275.<br />
DAM3168 LAYGEAR, 15/20/25/29 teeth 1 1979-80; 3 step layshaft, 1275.<br />
DAM4931 LAYGEAR, 15/21/26/30 teeth, A Plus type 1 1982 on; 3 step layshaft,<br />
not 1990-96, 1275 France .<br />
DAM6238 LAYGEAR, 15/21/27/31 teeth, A Plus type 1 1990-96, 3 step layshaft, 1275 France.<br />
6 22G931 LAYSHAFT, two step type 1 Fit to 22G927 and 22G1040 laygears.<br />
7 DAM3187 LAYSHAFT, three step type 1 Fit to all other laygears .<br />
8 2A3581 PLATE, locating reverse idler shaft/layshaft 1<br />
9 CHM141 BEARING, needle roller, laygear, large 2/1 Qty. 2 in 22G927/22G1040 gears only.<br />
10 88G396 BEARING, needle roller, laygear, small 1 Fit to 22G927 and 22G1040 gears only.<br />
11 13H9513 BEARING, needle roller, laygear, small 1 Fit to all other laygears .<br />
12 22G856 WASHER, thrust, small, 0.123-0.124" 1 Fit to 22G927 and 22G1040 laygears.<br />
(3.12-3.14mm)<br />
22G857 WASHER, thrust, small, 0.125-0.126" 1 Fit to 22G927 and 22G1040 laygears.<br />
(3.17-3.20mm)<br />
22G858 WASHER, thrust, small, 0.127-0.128" 1 Fit to 22G927 and 22G1040 laygears.<br />
(3.22-3.25mm)<br />
22G859 WASHER, thrust, small, 0.130-0.131" 1 Fit to 22G927 and 22G1040 laygears.<br />
(3.30-3.32mm)<br />
13 DAM3180 WASHER, thrust, small, 0.121-0.123" 1 Fit to DAM3169, DAM3168, DAM4931<br />
(3.07-3.12mm) and DAM6238 laygears .<br />
DAM3181 WASHER, thrust, small, 0.124-0.126" 1 Fit to DAM3169, DAM3168, DAM4931<br />
(3.15-3.20mm) and DAM6238 laygears .<br />
DAM3182 WASHER, thrust, small, 0.127-0.129" 1 Fit to DAM3169, DAM3168, DAM4931<br />
(3.22-3.27mm) and DAM6238 laygears .<br />
DAM3183 WASHER, thrust, small, 0.130-0.132" 1 Fit to DAM3169, DAM3168, DAM4931<br />
(3.30-3.35mm) and DAM6238 laygears .<br />
14 22G860 WASHER, thrust, large 1<br />
1st Motion Shaft<br />
15 22G1093 SHAFT, 1st motion, 17 teeth 1 1968-79; not 1275 models.<br />
22G1371 SHAFT, 1st motion, 18 teeth 1 1968-79; 1275 models.<br />
1st Gear<br />
29 22G1096 GEAR, 1st speed, 31 teeth 1<br />
30 22G2033 RING, baulk 1<br />
31 AAU1815 BEARING, needle roller, 1st speed gear 1<br />
32 22G837 JOURNAL, 1st speed gear 1<br />
1st/2nd <strong>Synchro</strong>niser<br />
33 DAM7455 GEAR ASS’Y, 1st/2nd synchroniser 1<br />
34 BLS107 BALL, synchroniser 3<br />
35 22G2262 SPRING, synchroniser 3<br />
2nd Gear<br />
36 22G1094 GEAR, 2nd speed, 26 teeth 1 1968-82.<br />
DAM4932 GEAR, 2nd speed, 26 teeth, A Plus type 1 1982 on; not 1990-96, 1275 (France).<br />
DAM6240 GEAR, 2nd speed, 25 teeth, A Plus type 1 1990-96, 1275 (France).<br />
37 22G2033 RING, baulk 1<br />
38 AAU1816 BEARING, needle roller, 2nd speed gear 1<br />
39 22G839 WASHER, thrust, 2nd speed gear 1<br />
40 22G843 PEG, 2nd speed gear 2<br />
41 22G154 SPRING, 2nd speed gear 1<br />
3rd Gear<br />
42 22G1095 GEAR, 3rd speed, 21 teeth 1 1968-82.<br />
DAM4933 GEAR, 3rd speed, 21 teeth, A Plus type 1 1982 on; not 1990-96, 1275 (France).<br />
DAM6241 GEAR, 3rd speed, 20 teeth, A Plus type 1 1990-96, 1275 (France).<br />
43 22G2033 RING, baulk 1<br />
44 AAU1816 BEARING, needle roller, 3rd speed gear 1<br />
45 22G947 WASHER, thrust, 3rd speed gear 1<br />
46 22G843 PEG, 3rd speed gear 1<br />
47 22G154 SPRING, 3rd speed gear 1<br />
3rd/4th <strong>Synchro</strong>niser<br />
48 DAM7456 GEAR ASS’Y, 3rd/4th synchroniser 1<br />
49 BLS107 BALL, synchroniser 3<br />
50 22G2262 SPRING, synchroniser 3<br />
Final Drive Pinion<br />
51 22G99 PINION, 15 teeth, 4.333:1 ratio 1 With 65 tooth 22G443 final drive gear.<br />
22G99 PINION, 15 teeth, 4.267:1 ratio 1 With 64 tooth 22G370 final drive gear.<br />
22G99 PINION, 15 teeth, 4.133:1 ratio 1 With 62 tooth 22G101 final drive gear.<br />
22G338 PINION, 16 teeth, 3.938:1 ratio 1 With 63 tooth 22G340 final drive gear.<br />
22A399 PINION, 17 teeth, 3.765:1 ratio 1 With 64 tooth 22A401 final drive gear.<br />
22A399 PINION, 17 teeth, 3.647:1 ratio 1 With 62 tooth 22G940 final drive gear.<br />
22A413 PINION, 18 teeth, 3.444:1 ratio 1 With 62 tooth 22A411 final drive gear.<br />
DAM3647 PINION, 15 teeth, A Plus, 4.333:1 ratio 1 With 65 tooth DAM3645 final drive gear.<br />
DAM3218 PINION, 16 teeth, A Plus, 3.938:1 ratio 1 With 63 tooth DAM3216 final drive gear.<br />
DAM4131 PINION, 17 teeth, A Plus, 3.765:1 ratio 1 With 64 tooth DAM4779 final drive gear.<br />
DAM4131 PINION, 17 teeth, A Plus, 3.647:1 ratio 1 With 62 tooth DAM4162 final drive gear.<br />
DAM2679 PINION, 18 teeth, A Plus, 3.444:1 ratio 1 With 62 tooth DAM2677 final drive gear.<br />
DAM2808 PINION, 19 teeth, A Plus, 3.211:1 ratio 1 With 61 tooth DAM2806 final drive gear.<br />
DAM2808 PINION, 19 teeth, A Plus, 3.105:1 ratio 1 With 59 tooth DAM6327 final drive gear.<br />
DAM5927 PINION, 20 teeth, A Plus, 2.950:1 ratio 1 With 59 tooth DAM5925 final drive gear.<br />
TCC10001 PINION, 21 teeth, A Plus, 2.762:1 ratio 1 With 58 tooth TCB10004 final drive gear.<br />
52 DAM7485 NUT, pinion retaining 1<br />
53 DAM6140 LOCK TAB, pinion nut 1<br />
Tel. 01249 721421 Fax. 01249 721316 www.somerford-mini.co.uk<br />
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