2a Gearbox number

[mikesolo]

Hi
I am having trouble locating the correct number, on the gearbox of my exarmy series 2a. Found a few numbers, but none look like the correct type of number for the gearbox. Where should it be stamped.
I need to buy replacement bearings and 1st gear for a 69 model, I don't think it is the origional box, as it has red stenciled letters painted on the box. Looks like a stores number. Most of the letters came off, when I used degreaser to remove the years of grease and mud.
Hope sombody can point me in thr right direction.

regards
Mike

[Lotz-A-Landies]

The number on an SII/SIIa is usually on the LHS of the selector cover, but many boxes don't have any numbers, having been lost when cases or tops being replaces etc.

The number is stamped in and the sequence should be similar to the RHD home model of the vehicle it's mounted in.

When Army gearbox repairs are necessary in-service, boxes are usually replaced with exchange units and the original sent off for factory or base re-build.

Diana

[mikesolo]

Hi
The lettering painted on the gearbox did say the word SERVICE and something else I think, but it was coverd in muck. It is a shame it washed off, when I cleaned the case. So it must be a replacement gearbox. Is there anyway to tell if it is Suffix B C or whatever.

Regards
Mike

[Lotz-A-Landies]

Hi Mike

Externally it is only possible to identify some aspects and remember it is possible to convert a suffix B into a suffix D merely by replacing the layshaft.

IIRC in the absence of numbers the SI, SII and SIIa "A" suffix boxes can be identified by the dip stick or the recess in the selector top (LHS) for the dip stick. By the later suffix SIIa boxes the recess is absent.

Essentially the big differences from Suff A are the big layshaft front bearing (suff B ) and the shoulder for 2nd layshaft gear instead of the circlip. The only other major differences are the sealed primary pinion/throwout at IIRC suffix G-H.

Diana

[JDNSW]

Didn't the gear ratios change slightly at some point?

John

[Lotz-A-Landies]

Didn't the gear ratios change slightly at some point?

Johnyes, but the thing that made the D suffix so much more reliable was the bigger layshaft bearing (suffix B ) and the shouldered layshaft the rest was just tweeking.

Suffix: A/B -- C on
1st - 2.996 - 3.6
2nd - 2.043 - 2.22
3rd - 1.377 - 1.5
4th - 1.000 - 1.00
Rev - 2.547 - 3.02

[fc110]

remember it is possible to convert a suffix B into a suffix D merely by replacing the layshaft.

AND the 2nd gear set!