viper771

Hello. While I was under the car today seeing what I needed to do, I decided to check out the tranny. I am not sure what year my TH400 is, but the tail seems to be really small. I was planning on rebuilding it, but I would rather have something "more correct" if it is possible. I will have to use some paint thinner on the data plate since it is covered over in a few layers of paint...

Anyway, my question is, would a th400 out of a gto work fine in my 68 olds (with a 455). That is prob. a newbish question but I wanted to be sure incase I do decided to swap, and rebuild that tranny instead. I will see if I can snap a few pictures in the next day or so when I crawl under her again. Thanks in advance!

Bluevista

A '68 GTO uses the short tailshaft 400?
It should work as far as I know?
My Vista uses that one IIRC.
I have an extra rebuilt one that came with the car, maybe I should look and make sure?
I have a '68 GTO too.

viper771

Is there any difference really in the long vs short tailshaft?? other than the length of the driveshaft that is? I THINK the tranny in the 442 came from a 73-up olds, but I won't know until I can read some of the data plate.

I am sorta getting rid of my 68 GTO, not really because I want to, but bec it is a BIG project. It is a 68 convertible that is pretty much rust on rust. I figured I could salvage some of it for the olds before I sold it.

Where in ohio are you?? I am in north west ohio, and live in south west ohio (by cinni). Thanks for the info too

From what I understand, all th400s are basically the same.. I just didn't know if the 442s were special in some way or not. I figure might as well ask while I have an extra one in another car I can get to semi easy

Olds64

As far as I know the only different TH 400s were the ones with switch pitch torque converters. That was pre-1967 I believe. All the others were the same internally. The only difference was the case.

viper771

thanks for the info! Learning new stuff all the time

compedgemarine

all A bodies with a TH400 used the short shaft version, the long tailshaft was for big cars. there are two versions as some have an extra clutch plate in them for heavy duty but any of the BOP trans will work.

matt69olds

71 and earlier trans used a sprag, they later ones used a roller clutch for second gear. After 68 Hydromatic added a thin snap ring to prevent case wear from the center support. Other than that, the only differences are number of clutches and valve body calibration.

viper771

thats good info guys! I will try and scrape the data plate a bit to see if I can get some numbers off of it. If all else fails, I can just rebuild the th400 out of the gto and throw it into the 442.