TH350 stuck in high gear!

HotRodGMC68 · 11-09-2009, 03:06 PM

I recently got a used TCI Competition TH350 from a buddy of mine. When he last used it real hard he hot lapped it 5 times and got it super hot. After that it was stuck in high gear.. he called TCI and they swore up and down that it's in the valve body. OK.. he had the valve body rebuilt at a local trans shop with a good rep for high performance parts. It worked great afterwards just cruisin' around the streets of town.. once he got on it real hard ONE time it was stuck in high gear again! He yanked it out and replaced it with a 400.

I aquiered the 350 and put a brand new TCI manual, fwd. pattern valve body in it... identical to what came out of it. Now the tranny is stuck in high gear wheather it's hot or cold! I do have reverse and neuteral.

Are there any tranny guru's out there that can lent some advice or knowledge on this thing?? I'd greatly appreciate it! I have torn down, inspected, and reassembled both valve bodies and they were both cherry from the get-go.

I haven't had time to tear it down the rest of they way, with having a 15 month old daughter taking up my free time..

Thanks a bunch..
Kurt S.

11-09-2009, 03:06 PM	#1
HotRodGMC68 Junior Member Join Date: Oct 2009 Posts: 7 Likes: 0 Liked 0 Times in 0 Posts	TH350 stuck in high gear! I recently got a used TCI Competition TH350 from a buddy of mine. When he last used it real hard he hot lapped it 5 times and got it super hot. After that it was stuck in high gear.. he called TCI and they swore up and down that it's in the valve body. OK.. he had the valve body rebuilt at a local trans shop with a good rep for high performance parts. It worked great afterwards just cruisin' around the streets of town.. once he got on it real hard ONE time it was stuck in high gear again! He yanked it out and replaced it with a 400. I aquiered the 350 and put a brand new TCI manual, fwd. pattern valve body in it... identical to what came out of it. Now the tranny is stuck in high gear wheather it's hot or cold! I do have reverse and neuteral. Are there any tranny guru's out there that can lent some advice or knowledge on this thing?? I'd greatly appreciate it! I have torn down, inspected, and reassembled both valve bodies and they were both cherry from the get-go. I haven't had time to tear it down the rest of they way, with having a 15 month old daughter taking up my free time.. Thanks a bunch.. Kurt S.