Manual gearbox - 3 synchromesh internal components

3 Synchro Internal Gearbox
1959-68
The 3 synchromesh gearbox was fitted to all Minis between 1959 and 1968. It is so called because synchromesh is only available on 2nd, 3rd and 4th
gears, 1st gear being of the 'crash' engagement type (probably the most common fault on this gearbox is jumping out of first gear, followed closely by
laygear bearing and layshaft failure). A proper first speed gear was inserted in the gearbox in 1968, at last receiving the great benefit of synchromesh
engagement; this gearbox is termed 4 synchro and its internal components are covered in the next section of the catalogue.

If you've not been inside a 3 synchro Mini gearbox before or you can't remember when you last did, please read these notes carefully - they could save
you a lot of heartache. The gearbox internal components were revised several times, with the changes being introduced at broadly the same times
across all of the A series engined cars in the BMC range. Essentially, these revisions boil down to three types of gearbox (with a handful of components
being awkward exceptions to the rule, of course... we'll explain those as best we can as we go along).

The first 3 synchro gearbox fitted to the Mini is known as the 'cone synchromesh' gearbox, because of its use of cones to aid gearchanging rather than
the more efficient baulk rings, which arrived in 1962. The next change occurred in 1963 or 1964 (depending on model) when the angles of the gear teeth
were changed to quieten the baulk ring gearbox. The modified gears were known as B Type gears, the 1962-63 gears retrospectively becoming known
as A Type gears. So there you have it: 1959-62 Cone Synchromesh gearbox, 1962-63/64 A Type Gears gearbox and 1963/64-68 B Type Gears gearbox
(plus, in 1963-64, an A Type gearbox with B Type 1st/2nd synchroniser and reverse idler...!).

Gearbox Identification
Between the three gearbox types, many, many components are not interchangeable. This makes it especially important to identify your gearbox before
ordering parts, which can be difficult, particularly when trying to work out whether you have A or B Type gears. Originally, gearbox cases were stamped
with a part number denoting the gear types within and the model application; however this has become quite irrelevant over the years as gearboxes have
been rebuilt, very often with different components to overcome the lack of original parts availability.

The only surefire way to identify the gearbox nowadays is to inspect the internals with a small check list to hand, paying particular attention to:
(i) the presence of synchro cones or baulk rings (Cone Synchro box for the first, A Type and B Type boxes for the second);
(ii) If baulk rings are present, do the second and third gears run on bushes - the bush interlocking ring being visible between the two gears on the
mainshaft gear cluster - or do they run on bearings (A Type gears except 1963 Cooper 997 for bushes, A Type gears 1963 Cooper 997, hybrid A/B Type
and B Type gears for bearings).
(iii) The number of teeth on the laygear (13/19/24/28 for non Cooper, 13/19/23/26 for Cooper, other combinations for Special Tuning options)
(iv) Are the laygear bearing circlips on the outside or inside of the bearings (Cone Synchro and A Type gears except 1963 Cooper 997 for outside circlips,
A Type gears 1963 Cooper 997, hybrid A/B Type and B Type gears for inside circlips).

The laygear should tell you which combination of gears you have... 'should' because the laygear part number was traditionally stamped on the component
between the largest and second largest gears, but some reproduction gears (mostly in the case of 22G1100) don't have this. Identifying your laygear
allows you to work out what other gears have been used in the gearbox, since they were designed to go together as matched gear sets and are usually
not interchangeable. For this reason, all the other major components in this section use the application remarks shown alongside the laygears
- even if it's a bit long-winded sometimes, it positively matches the sets together.

Be careful with 848 and 997 Cooper A Type gears 'boxes, though - some have been converted from cone synchro to baulk ring A Type gears, retaining
the original laygear; some other components used in cone to baulk ring converted gearboxes are unique and most are not listed here (this catalogue
section is complicated enough!). The 22G1100 laygear, incidentally, was for a short period at the start of its life known as and stamped as 22G232.
If you find 22G83 or 22G714 on your laygear, you have an Austin/Morris 1100 or 1300 gearbox, not a Mini one.

Parts Availability
Unfortunately, parts availability ranges from almost hopeless (Cone Synchromesh and A Type gears) through to pretty awful (B Type gears) and this
situation is unlikely to improve greatly. The B Type gears do, however, benefit marginally from the fact that the MG Midget continued to use versions of
them until 1974, which slightly increases parts demand and availability. Many parts listed in this section are therefore shown only as a matter of
reference.

We will always do our utmost to help you seek out parts for your gearbox, but by rule of thumb the thing to remember here is don't embark on a 3
synchro gearbox rebuild until (a) you're absolutely sure you have the parts you need; and (b) you've weighed up seriously the benefits of sourcing another,
better condition, gearbox instead. You have been warned...

Close Ratio and Straight Cut Gears
Close ratio straight cut gear sets are available to build into gearboxes with B Type Gears components, as a special order. Please contact us for
details. Similarly, please contact us if you have factory-optional helical close ratio, straight cut close ratio or straight cut standard ratio gears in your
gearbox and you require replacement parts.

Reverse Idler Gear
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
1	22A377	REVERSE IDLER, with bush, 18 teeth	1	1959-64; 848 models, Cone Synchro and A Type gears.
				1961-62; 997 Cooper, Cone Synchro.
				1962-63; 997 Cooper, A Type gears.
				1963; 997 Cooper, A Type gears.
	22G202	REVERSE IDLER, with bush, 18 teeth	1	1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with
				B Type 1st/2nd synchroniser and reverse gears.
				1964-68; 848 and 998 (not Cooper) models, B Type gears.
				1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
2	2A3475	BUSH, reverse idler	1
3	DAM8038	SHAFT, reverse idler	1

Laygear
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
4	22A381	LAYGEAR, 13/19/24/28 teeth	1	1959-64; 848 models, Cone Synchro and A Type gears.
	22A350	LAYGEAR, 13/19/23/26 teeth	1	1961-62; 997 Cooper, Cone Synchro.
	22G76	LAYGEAR, 13/19/23/26 teeth	1	1962-63; 997 Cooper, A Type gears.
	22G197	LAYGEAR, 13/19/23/26 teeth	1	1963; 997 Cooper, A Type gears.
	22G204	LAYGEAR, 13/19/23/26 teeth	1	1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with B Type 1st/2nd synchroniser and reverse gears.
	22G231	LAYGEAR, 13/19/24/28 teeth	1	1964-68; 848 and 998 (not Cooper) models, B Type gears.
	22G1100	LAYGEAR, 13/19/23/26 teeth	1	1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
5	22A1371	LAYSHAFT	1
6	2A3581	PLATE, locating reverse idler shaft and layshaft	1
7	88G396	BEARING, needle roller, laygear	2
8	22G277	DISTANCE PIECE, bearing	1
9	22G278	CIRCLIP, bearing retaining	2
10	88G325	WASHER, thrust, large	1	0.123-0.124" (3.12-3.14mm).
	88G326	WASHER, thrust, large	1	0.125-0.126" (3.17-3.20mm).
	88G327	WASHER, thrust, large	1	0.127-0.128" (3.22-3.25mm).
	88G328	WASHER, thrust, large	1	0.130-0.131" (3.30-3.32mm).
11	88G324	WASHER, thrust, small	1

1st Motion Shaft
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
12	22A88	SHAFT, 1st motion, with synchro cone, 19 teeth	1	1959-62; 848 models, Cone Synchro.
	22A588	SHAFT, 1st motion, 19 teeth	1	1962-64; 848 models, A Type gears.
	22A257	SHAFT, 1st motion, with synchro cone, 20 teeth	1	1961-62; 997 Cooper, Cone Synchro.
	22A416	SHAFT, 1st motion, 20 teeth	1	1962-63; 997 Cooper, A Type gears.
	22A592	SHAFT, 1st motion, 20 teeth	1	1963; 997 Cooper, A Type gears.
				1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with B Type 1st/2nd synchroniser and reverse gears.
	22A979	SHAFT, 1st motion, 19 teeth	1	1964-68; 848 and 998 (not Cooper) models, B Type gears.
	22A982	SHAFT, 1st motion, 20 teeth	1	1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
13	2A3693	CONE, synchronising	1	Fit to 22A88 and 22A257 1st motion shafts.
Note that synchro cones have to be shrunk onto their respective gears and then finally machined - not a task for most home-based Mini restorers.

Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
14	22G2033	RING, baulk	1	Fit to 22A588, 22A416, 22A592, 22A979 and 22A982 1st motion shafts.
15	22G314	BEARING, 1st to 3rd motion shaft	1	Fit to 22A88, 22A588, 22A257 and 22A416 1st motion shafts.
	CHM172	BEARING, needle roller, 1st to 3rd motion shaft	1	Fit to 22A592, 22A979 and 22A982 1st motion shafts.
16	2A3709	BEARING, 1st motion shaft	1	In gearbox case.
17	2A3710	CIRCLIP, bearing retaining	1	0.094-0.096" (2.39-2.44mm)
	2A3711	CIRCLIP, bearing retaining	1	0.097-0.099" (2.46-2.51mm)
For the 1st motion shaft bearing supporting the nose of the shaft in the flywheel housing, please see the 'Flywheel Housing and Clutch Cover' section.

3rd Motion Shaft
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
18	2A3719	SHAFT, 3rd motion	1	1959-61; 848 models, Cone Synchro.
				1961; 997 Cooper, Cone Synchro.
	22A425	SHAFT, 3rd motion	1	1961-62; 848 models, Cone Synchro.
				1961-62; 997 Cooper, Cone Synchro.
	22A421	SHAFT, 3rd motion	1	1959-62; Cone Synchro to baulk ring synchro conversion item.
	22G70	SHAFT, 3rd motion	1	1962-64; 848 models, A Type gears.
				1962-63; 997 Cooper, A Type gears.
				1963; 997 Cooper, A Type gears.
				1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with
				B Type 1st/2nd synchroniser and reverse gears.
	22G392	SHAFT, 3rd motion	1	1964-68; 848 and 998 (not Cooper) models, B Type gears.
				1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
19	22A422	WASHER, spacing	1	1959-62; Cone Synchro to baulk ring synchro conversion item.
20	2A3712	BEARING, 3rd motion shaft	1	Fit to 2A3719, 22A425 and 22A421 3rd motion shafts.
	22A575	BEARING, 3rd motion shaft	1	1959-62; for Cone Synchro to baulk ring type gearbox case conversion. Fit to 2A3719 and 22A425 3rd motion shafts.
	AAU1365	BEARING, 3rd motion shaft	1	Fit to 22G70 and 22G392 3rd motion shafts.
21	2A3713	RING, spring, bearing retaining	1	Fit to 2A3712 bearing.
	ADU4992	RING, spring, bearing retaining	1	Fit to AAU1365 bearing.
22	2A3716	RETAINER, 3rd motion shaft bearing	1	For 2A3712 3rd motion shaft bearing.
	22A522	RETAINER, 3rd motion shaft bearing	1	For AAU1365 3rd motion shaft bearing.
23	SH505081	SCREW, coarse thread, retainer to gearbox case	4
24	DAM2377	LOCK TAB, screw	2
25	2A3714	SHIM, retainer	A/R	0.003" (0.076mm)
	2A3715	SHIM, retainer	A/R	0.010" (0.254mm)

1st/2nd Synchroniser
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
26	22A433	GEAR ASS'Y, 1st/2nd synchroniser	1	1959-62; 848 models, Cone Synchro.
				1961-62; 997 Cooper, Cone Synchro.
	22G440	GEAR ASS'Y, 1st/2nd synchroniser	1	1962-64; 848 models, A Type gears.
				1962-63; 997 Cooper, A Type gears.
				1963; 997 Cooper, A Type gears.
	22A1021	GEAR ASS'Y, 1st/2nd synchroniser	1	1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with B Type 1st/2nd synchroniser and reverse gears.
				1964-68; 848 and 998 (not Cooper) models, B Type gears.
				1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
The 1st speed outer ring for the 22A1021 gear assembly is sometimes available separately as the repair part 22A1021A. However its compatibility with an old 2nd speed synchro hub cannot be completely guaranteed as the outer ring and hub were designed to be supplied as a matched pair.

Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
27	BLS107	BALL, synchroniser	6/3	Qty. 6 used on very early Cone Synchro.
28	22A367	SPRING, synchroniser	6/3	Qty. 6 used on very early Cone Synchro.
29	22G89	PLUNGER, 2nd speed synchroniser	1

2nd Gear
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
30	22A90	GEAR, 2nd speed, with synchro cone, 28 teeth	1	1959-62; 848 models, Cone Synchro.
				1961-62; 997 Cooper, Cone Synchro.
	22A582	GEAR, 2nd speed, 28 teeth	1	1962-64; 848 models, A Type gears.
				1962-63; 997 Cooper, A Type gears.
	22G194	GEAR, 2nd speed, 28 teeth	1	1963; 997 Cooper, A Type gears.
				1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with
				B Type 1st/2nd synchroniser and reverse gears.
	22A980	GEAR, 2nd speed, 28 teeth	1	1964-68; 848 and 998 (not Cooper) models, B Type gears.
				1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
31	2A3693	CONE, synchronising	1	Fit to 22A90 2nd speed gear.
32	22G2033	RING, baulk	1	Fit to 22A582, 22G194 and 22A980 2nd speed gears.
33	2A3042	WASHER, thrust, 2nd speed gear	1	1959-64; all Cone Synchro and A Type 2nd speed gears.
34	2A3298	BUSH, 2nd speed gear	1	Fit to 22A90 and 22A582 2nd speed gears.
35	22G374	RING, interlocking, 2nd and 3rd speed gear bushes	1	Fit to 22A90 and 22A582 2nd speed gears.
36	22G186	COLLAR, locking, 2nd speed gear	1	Fit to 22G194 and 22A980 2nd speed gears.
37	22G149	BEARING, needle roller, 2nd speed gear	26	Fit to 22G194 and 22A980 2nd speed gears.
38	22G157	WASHER, 2nd speed gear locking collar	2	Fit to 22G194 and 22A980 2nd speed gears.
39	22A495	PEG, 2nd speed gear locking collar	1	Fit to 22G194 and 22A980 2nd speed gears.
40	22G154	SPRING, 2nd speed gear locking collar	1	Fit to 22G194 and 22A980 2nd speed gears.

3rd Gear
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
41	22A89	GEAR, 3rd speed, with synchro cone, 23 teeth	1	1959-62; 848 models, Cone Synchro.
	22A583	GEAR, 3rd speed, 23 teeth	1	1962-64; 848 models, A Type gears.
	22A261	GEAR, 3rd speed, with synchro cone, 24 teeth	1	1961-62; 997 Cooper, Cone Synchro.
	22A415	GEAR, 3rd speed, 24 teeth	1	1962-63; 997 Cooper, A Type gears.
	22G195	GEAR, 3rd speed, 24 teeth	1	1963; 997 Cooper, A Type gears.
				1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with B Type 1st/2nd synchroniser and reverse gears.
	22A981	GEAR, 3rd speed, 23 teeth	1	1964-68; 848 and 998 (not Cooper) models, B Type gears.
	22A983	GEAR, 3rd speed, 24 teeth	1	1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
42	2A3693	CONE, synchronising	1	Fit to 22A89 and 22A261 2nd speed gears.
43	22G2033	RING, baulk	1	Fit to 22A583, 22A415, 22G195, 22A981 and 22A983 2nd speed gears.
44	2A3290	BUSH, 3rd speed gear	1	Fit to 22A89, 22A583, 22A261 and 22A415 3rd speed gears.
45	22A550	WASHER, thrust, 0.212-0.213" (5.38-5.41mm)	1	Fit to 22A89, 22A583, 22A261 and 22A415 3rd speed gears.
	22A536	WASHER, thrust, 0.214-0.215" (5.43-5.46mm)	1	Fit to 22A89, 22A583, 22A261 and 22A415 3rd speed gears.
	22A537	WASHER, thrust, 0.216-0.217" (5.48-5.51mm)	1	Fit to 22A89, 22A583, 22A261 and 22A415 3rd speed gears.
	22A538	WASHER, thrust, 0.218-0.219" (5.53-5.56mm)	1	Fit to 22A89, 22A583, 22A261 and 22A415 3rd speed gears.
46	22A495	PEG, thrust washer	1	Fit to 22A89, 22A583, 22A261 and 22A415 3rd speed gears.
47	22A528	SPRING, thrust washer	1	Fit to 22A89, 22A583, 22A261 and 22A415 3rd speed gears.
48	22G149	BEARING, needle roller, 3rd speed gear	26	Fit to 22G195, 22A981 and 22A983 3rd speed gears.
49	22G196	Collar, locking, 3rd speed gear	1	Fit to 22G195, 22A981 and 22A983 3rd speed gears.
50	22A495	PEG, 3rd speed gear locking collar	1	Fit to 22G195, 22A981 and 22A983 3rd speed gears.
51	22G154	SPRING, 3rd speed gear locking collar	1	Fit to 22G195, 22A981 and 22A983 3rd speed gears.

3rd/4th Synchroniser
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
52	22A26	GEAR ASS'Y, 3rd/4th synchroniser	1	1959-62; 848 models, Cone Synchro.
				1961-62; 997 Cooper, Cone Synchro.
	22G97	GEAR ASS'Y, 3rd/4th synchroniser	1	1962-64; 848 models, A Type gears.
				1962-63; 997 Cooper, A Type gears.
	22G410	GEAR ASS'Y, 3rd/4th synchroniser	1	1963; 997 Cooper, A Type gears.
				1963-64; 997/998 Cooper, 1071 Cooper S, A Type gears with B Type 1st/2nd synchroniser and reverse gears.
				1964-68; 848 and 998 (not Cooper) models, B Type gears.
				1964-68; 998 Cooper, 970/1071/1275 Cooper S, B Type gears.
53	BLS107	BALL, synchroniser	6/3	Qty. 6 used on Cone Synchro.
54	22A367	SPRING, synchroniser	6/3	Qty. 6 used on Cone Synchro.

Final Drive Pinion
Ill. No.	Part No.	Description	Qty. Rqd.	Remarks
55	22G99	PINION, final drive, 15 teeth	1	4.333:1 ratio (with 65 tooth 22G443 final drive gear).
	22G99	PINION, final drive, 15 teeth	1	4.267:1 ratio (with 64 tooth 22G370 final drive gear).
	22G99	PINION, final drive, 15 teeth	1	4.133:1 ratio (with 62 tooth 22G101 final drive gear).
	22G338	PINION, final drive, 16 teeth	1	3.938:1 ratio (with 63 tooth 22G340 final drive gear).
	22A399	PINION, final drive, 17 teeth	1	3.765:1 ratio (with 64 tooth 22A401 final drive gear).
	22A399	PINION, final drive, 17 teeth	1	3.647:1 ratio (with 62 tooth 22G940 final drive gear).
	22A413	PINION, final drive, 18 teeth	1	3.444:1 ratio (with 62 tooth 22A411 final drive gear).
56	2A3575	NUT, pinion retaining	1	Fit to 2A3719 3rd motion shaft.
57	2A3576	LOCK TAB, pinion nut	1	Fit to 2A3719 3rd motion shaft.
58	22G48	NUT, pinion retaining	1	Fit to 22A425, 22G70 and 22G392 3rd motion shafts.
59	DAM6140	LOCK TAB, pinion nut	1	Fit to 22A425, 22G70 and 22G392 3rd motion shafts.

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Manual gearbox - 3 synchromesh internal components

WASHER-LAYGEAR-THRUST-LARGE-3 SYNCRO-.127-.128'' 3.22-3.25mm

WASHER-LAYGEARTHRUST-LARGE-3 SYNCRO-.125-.126'' 3.17-3.20mm

WASHER-LAYGEAR-THRUST-LARGE-3 SYNCRO-.123-.124'' 3.12-3.14mm

CIRCLIP-LAYGEAR BEARING RETAINING-3 SYNCHRO

DISTANCE PIECE-BEARING TO LAYGEAR-3 SYNCHRO

LAYSHAFT-3 SYNCHRO GEARBOX

LAYGEAR-13/19/23/26 -3 SYNCHRO-B TYPE 998 COOPER & ALL S

LAYGEAR-13/19/23/26 TEETH-3 SYNCHRO-B TYPE 850/998 '64-'68

LAYGEAR-13/19/23/26 TEETH 997/998/1071cc A TYPE-'63-'64

LAYGEAR-13/19/23/26 TEETH-997 COOPER-A TYPE GEARS-1963

LAYGEAR13/19/23/26 TEETH-997 COOPER-A TYPE-'62-'63

LAYGEAR-13/19/23/26 TEETH-997 COOPER-CONE SYNCHRO '61-'62

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