I just got my rebuilt th350 back and installed it. There is a problem though, I had it rebuilt so it would shift from 1st to 2nd at 5800 rpm, then 2nd to 3rd at ~5500 rpm. The problem is it shifts out of 1st at about 5000 to 5500 and barks the tires, then bogs down to 3rd gear starting about 3k.

If I manually shift the tranny I can bark the tires going into 2nd and 3rd. (tires are 275/50/r15 bfg's with 14 psi in them) So the tranny is built to shift super hard.

I also had the hole for the kick down cable blocked off since this car is for drag racing.

I'm running 4.10 gears if that makes any difference.

I know I need to ask all these questions to the guy that rebuilt it for me, but he's out of his shop now and I'm looking for others opinions or ideas... am I doin something wrong?

Thanks for any help you can give me!

 

I'm beginning to think its from a lack of a kick down cable... Its not letting the tranny know i'm WOT so it just drops to 3rd rather than spinning all the way out of 1st and into 2nd like it should.

Anyone else think this is the problem?

 

I believe you're correct. I'm only used to the 700-R4's, which I know the TV cable controls shift points, firmness, etc. because they're hydraulic transmissions. I'm not sure if the TH350 is the same way. But it makes sense to me. Although if that is the case, it's strange to me that it will wind out in first gear at ALL, instead of just giving you a normal part throttle shift. I wonder if you've got a trans with a vacuum modulator to control its shift points, or if that's all done through the kickdown cable.