TH 400 Replacement

[tgtaylor64]

I need to replace the TH400 in my 85 M1009. Can any GM TH400 bolt up? Must it be from a 4WD? Must it be from a diesel? Any short shaft vs. long shaft issues? I can find many but just want to get the right one, if it matters.

 

[original]

Any th400 will bolt up correctly; however, you are better off buying one from a 4wd. If you buy a 2wd th400 you will have to disassemble the old and replacement transmission in order to change the tail. If there is any way possible, save yourself some time and money and have it professionally rebuilt. You might as well flip a coin on any used transmission. I've had 4 out of 10 in various projects were the used transmission didn't last long. Do it right and know your ride is reliable. Good luck, mate.

 

[4x4 Forever]

I believe the 4x4 tranny housings are heavier than the 2x's. At least that is what I was told by several tranny shops and the GM parts guy I use...

 

[Speddmon]

I would think that you would also want to re-use your old torque converter? The converter stall speed from a th400 on a 350 gas engine would be different than the 6.2 diesel.

 

[Asmoday]

The TH400's used in the CUCV's have a heavy duty case. The case will have a HD cast into it on the upper right portion of the bell. If you look up there with a flashlight and mirror you can see it. These cases are much beefier than your normal TH400 case and have a thicker flange area than even the regular truck cases where it bolts to the block. If you get yours rebuilt make SURE they use your case as the HD cases are very desirable. Rock crawler guys love them and they are considered some of the best TH400 cases you can get which can cause them to bring big money. I have seen a few CUCV's without the HD cases but as a rule they usually have them. If you have one... Keep it...!

 

[Whitfield]

The later Jeep AMC 4wd Th-400 will not bolt up ~ nor will the Cadillac Olds Buick Pontiac 2wd Th-400.