# Anyone using a TH400 Shift kit?



## FlambeauHO (Nov 24, 2011)

Didn't see any good threads on this, anyone using a B&M or similar shift kit in their TH400? Nothing wrong with my tranny but I wouldn't mind firming up the shifts a bit. Any input?


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## bigD (Jul 21, 2016)

Most agree that the TransGo shift kits are the best.

https://www.summitracing.com/search...ansmission-shift-kits/transmission-type/th400


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## PontiacJim (Dec 29, 2012)

bigD said:


> Most agree that the TransGo shift kits are the best.
> 
> https://www.summitracing.com/search...ansmission-shift-kits/transmission-type/th400


X2. Had a Trans-Go shift kit installed when I had my brother's Plymouth 904 automatic rebuilt. Shifts normally in Drive, and manually when you drop it down into Low and Second. Nice crisp firm shifts. :thumbsup:

I believe I used a NAPA shift kit rather than the B&M kit in a TH400 when I was younger. Was told it would do the same thing, but it was cheaper in price. It did the job.


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## FlambeauHO (Nov 24, 2011)

Thanks guys, anyone using the transgo in a TH400 that can comment on the driveability? I just want to firm it up a bit, not break my seat back ?


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## joelau27 (Sep 22, 2018)

I've had a B&M kit in my '69 TH400 for 30 plus years. Shifts great, nice and firm. I can get rubber going into second if I shift Manually.


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## geeteeohguy (Feb 2, 2008)

No need to buy a kit. You can modify the separator plate for free. There is information on exactly what to do on line.....you can probably find it by googling "TH400 separator plate modification" or the like. I got my information from Jakeshoe's transmission 8 or 9 years ago. Drilled two holes slightly larger, and it firmed up the 1-2 and 2-3 shifts. No need to go crazy, and drill huge holes, or the unit will really bang shift all the time. I went to a .090" hole, I think, instead of the recommended .120" It worked great. All you are doing is allowing more fluid into the circuit faster to apply the clutches faster and harder, basically. There's a guy on the PY forums, Half inch Stud, who is very knowledgeable about this procedure.


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## BearGFR (Aug 25, 2008)

Something else you can try easily is a fluid type change. Ford Type F instead of Dexron has been known to wake them up quite a bit.

Also, the "Jakeshoe" that GeeTee referred to is the guy who built my TH400 for my car. He has a transmission shop just north of Denton, TX. He doesn't use anyone's kit on his builds, instead he has developed his own calibrations over the years. He has his own transmission dyno that he tests every build on before he returns them to a customer. Mine has been trouble free.

Bear


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## FlambeauHO (Nov 24, 2011)

Good info guys, thanks!! I'll do some research, unfortunately I ordered a Transgo kit last night after reading around. I can always return it... Tranny is on the list after my cam gets here anyway. I've had a slow leak for 22 years from the tranny when cold. It will be sorted out this time!


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