IIA or III tranny

[cousindave]

I recently destroyed my reverse gear in my series III. The gearbox still works perfectly through the gears; just no reverse. I have a series IIA box that I have lying around that functions perfectly. I was wondering if I should repair the series III BOX or go ahead and put in the IIA box instead. The series III box is an early type with the brass bushing pressed into the reverse gear. Also, there is an occasional clunk when in four wheel drive. Was wndering if this could be the transfer case, I cannot tell where the clunk comes from.

[Apis Mellifera]

The IIA gearbox is not a drop-in. The clutch actuation differs between the IIA and III. I went through this myself. My clunk turned out to be a loose nut on the layshaft. It is possible that the relevant IIA innards will fit into the III, but since you'll have it out anyway, I'd just rebuild the III box and refit.

[cousindave]

So you think it's not just a matter of changing the bellhousing between tranny's and bolting it all back in? Tried searching for answers but muchconflicting information found.

[Apis Mellifera]

I don't know the answer to that one. Once I found the clutch was going to be a problem, I stopped looking at the IIA box and bought one from a III. If have them side by side, with measuring tools, and a parts book to compare parts numbers, you might answer that question. Hopefully someone who has been down this road can offer a definitive answer. I'd like to know myself - I could use another gearbox and know of a IIA nearby.

[73series88]

i have a series early 2a motor in my series 3 with a series 3 gearbox
all i had to do is put a series 3 pressure plate and clutch plate.
i learned the hard way when i put these together originally,
i left the 2a clutch parts in and everything inside got bound up.
thought i seized the motor. wouldnt turn
but with the help of les we figured out thats what it was.
Thanks Les.
aaron

ps i love the full syncro gearbox
makes driving alot eaiser
not up for all that double clutching

[siii8873]

I had an engine failure on my SIII. I installed a SIIA engine in the SIII. Just changed the bellhousing and clutch assemble with it all was fine.
Not exacly what your asking but makes me think if you change bell housing and clutch with it you would be OK

[rejeep]

i just ordered a recon S3 box to swap into my 109..
if you want my old one to rebuild to reduce downtime we can work something out..

[Les Parker]

You can swap the trans of the late IIa's and Series III's, by changing the clutch assy's and gearbox bell housing's.

Caution :- Check the bell housing of the IIa, does it have 2 grommets, 1 blank (on LH side) and 1 on the RH for the Clutch mechanism? If so, no go!

Also, if you do the swap, balance the trans/t.box on the h. brake drum, so gravity is working with you.

Hope this helps,

[Tim Smith]

<hijack>
If anyone has a series box or two that they want rid of, drop me a line.
</hijack>

As has been said, you could swap transmissions or you could rebuild your current box. I'd rebuild the SIII box simply because it shouldn't be too expensive to fix. Then you could sell the IIA box on the side. These boxes are pretty easy to rebuild so long as you follow the specs.

That clunk in four wheel drive is likely bound up pressure being released because of the lack of a centre diff. I'm kind of guessing about that but either way, it shouldn't be related to the transmission but rather the transfercase.