Bracket Talk
Strange TH350 issue. HELP!

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https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/1267096007

July 23, 2023, 09:10 PM
Jason Haley
Strange TH350 issue. HELP!
I have a TH350 in my car that has a forward pattern manual valve body. What's happening is the car will feel like it's in a bind right before the shift point in first gear. It doesn't do it every pass, and it doesn't seem to have a consistent, predictable pattern of doing it either. I've noticed that sometimes after doing it, it'll push a small amount of fluid out of the vent as well. My transmission builder went through it earlier this year and found a few small issues, but nothing really stood out that could be causing this. Another transmission builder told me that he's seen "cross feeding" cause this and to try removing the valve body gasket? Also, for what it's worth, this transmission was in the car when it had a rear end failure a few years ago. Is it possible there's a hairline crack inside the case that's causing intermittent issues?


Slow S-10
Slower Cutlass
July 23, 2023, 11:11 PM
rusty
or a warped valve body


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 26, 2023, 11:07 AM
Goob
I had a TH-400 do that, replacing the case cured it after all the other valve body replacement and inspection dances.


"Despite the high cost of living, it remains popular."
Dave Cook
N375
July 26, 2023, 11:19 AM
1320racer
you need a new trans builder that knows what he is doing.
July 26, 2023, 07:59 PM
Top355x
Had a turbo 350 years ago doing weird **** binding occasionally ended up one of the balls in the valve body was not completely round and it would bleed threw at times
August 10, 2023, 07:29 AM
Jason Haley
UPDATE:

I put a powerglide in the car and the issues went away, so obviously something is wrong with the TH350 internally. My only guess is something happened to the case when the car broke the rear end.


Slow S-10
Slower Cutlass
August 10, 2023, 07:30 AM
1320racer
as I stated

quote:
Originally posted by 1320racer:
you need a new trans builder that knows what he is doing.

August 10, 2023, 08:16 AM
ferndaleflyer
Ed most of these guys don't want to pay the price for a good transmission builder. Also most of the good ones are overwhelmed with work just because they ARE good.
August 10, 2023, 08:27 AM
1320racer
True and they typically never learn. Long ago I made the move to the best 3 speed trans builder in the country after my local guy couldn't build a turbo400 that would make 100 passes with the last rebuild making only 6 passes and I never regretted that decision and while I no longer run a 3 speed, I'd go right back to him if I ran stock, super stock or a heads up class. BTW, he once told me any idiot can build a glide. Big Grin
August 10, 2023, 09:11 AM
markemark
The builder I use has a dyno and my th400 has been on it.
August 10, 2023, 09:12 AM
1320racer
mine too
August 10, 2023, 12:10 PM
ferndaleflyer
Mine to. But they work and last.
August 10, 2023, 02:21 PM
1320racer
ATI still doing yours?