THM 400-3L80 Center Support Help?

[Hotburn76]

I am currently rebuilding the transmission for a 90 454ss truck. When removing old bushing I damaged the center support. Ordered a new one from trans star and all seemed well. During final assembly When putting in the bolt for the support it would not go in all the way. Noticed that my old center support was threaded all the way into the support for a longer bolt. Went to two different shops and none seem to understand why I have a longer bolt. They have only ever worked with the ones that use the short bolt. All have said to just put in the new support with a short style bolt and will work fine. Is this true and has anyone else seen this?

 

[patprimmer]

Maybe the longer bolt was not original and was used on your box, along with a tap, as a repair when a thread was stripped.

How many threads are engaged with the short bolt tightened in position.

Regards

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[jimg964]

Sorry for the late reply.

Could you have a bolt from a TH-425? This is the front wheel drive cousin of the TH-400 used in the late 60's to early 70's.

I am not sure, it has bee 20+ years since I was in one, but, I do still have the special socket that is longer and narrower than what's necessary for a TH-400. Wouldn't surprise me the bolt is longer, too.

Good Luck,

Jim