Overdrive question...

Hello all.
Well, I am almost done with my midgets, now I am ready for the "B"s. I just got a great deal on a complete overdrive transmission from a 74 MGB. It has been bench tested and should be good to go. I have a 74 and a 75, so I am guessing this should be a fairly straight forward process. Included in the deal, however, is an additional OD unit and a shaft to convert a non OD trans to an OD trans.
I really like the idea of having two OD MGBs, but putting a new shaft in sounds a little scary. I have fixed just about everything else on these vehicles, except diving into the quagmire of a trans. Is this something, with a Chitlon book and online videos, I should attempt? Also, I would like to put the extra into my 64. Would that make it even more difficult? I'm guessing this is a "newer" OD.

Any/all opinions welcome. (Just please, no offers to buy my "extra", I really want to use them both)

Thanks in advance,

TJ

Hi TJ - I've never been in a transmission, but I see you mentioned the Chilton maunal there. FWIW, I found that manual useless to the point I was happy to give it away. The one most recommended is by Robert Bentley, pricey but thorough and very available - you may find downloads of it as well. Maybe this will spare you some irritation :) I bet there's vids and articles (try this site's library) awaiting you too ... best of luck

~Marco and PLT~

i agree with marco. a chilton book is not going to help you on this one.

Swapping out the transmissions is fairly straightforward and not too difficult. There are things you will want to do once the transmission is out such as replacing motor and transmission mounts. Also, install a clutch kit and have the flywheel resurfaced. Should you have any doubts about the ring gear, replace it as well. FWIW, I used brown lunch bags to hold the many nuts and bolts and marked each bag with its contents. This made reassembly much easier and no guess work about where the parts were to go. Have fun.

AFAIK the later OD gearbox won't fit in an early car making modifying the transmission tunnel. Also if your early car has a 3-main engine you'd need the smaller diameter input shaft to fit the crank.

Jim

Also I think there is a difference in the engine backing plate from later gearbox to early. It seems I have had to swap plates.

Your '64 3 synchro transmission won't accept the later design OD unit. Apples and oranges. Installing the OD unit, on one of your later transmissions, will also require the OD adapter housing. Even with all of the correct components, it is a fair amount of work if you've never been inside one of these transmissions before. However, it can be done with the right instructions and a little patience. RAY

awhile back - i recall reading that the LH OD unit is mated to a slightly different main case - a bolt hole pattern difference as i recall - so it may not even be possible to hook an LH to a std 4-spd caed w/o some hasssssssles

Some good info here:

http://custompistols.com/cars/articles/ts_od_gearbox.htm

Thanks everyone for the input. The trany is on the way! I will let you know how this whole experiment unfolds. From what I am hearing, it sounds like I might want to avoid puting this in the 64. I have a great 79 MGB frame that might end up with the "extra" OD.

Thanks,

TJ