Installed a Yank, but what's wrong?
 

Just got done installing a yank 4k for a th350, it feels extremely loose like I expected. But when I hit on the hwy where it won't spin, it revs right to 6500 but pulls but I don't see the tach move again, so I hit the rev limiter of course. Pulling back up to the house I come around a corner and it almost felt like the tranny slipped and then was fine. Any ideas what to check for?

Thanks

I would suggest adding some fluid , Sounds like your still a little low.

Fluid level good, what else?

Did you have it tuned?

Car was previously tuned with the 4l60e, the th350 is a full reverse manual valvebody with a tbrake.

Not to sound like a broken record but did you double and tripple check your fluid?? New converters will "burp" sometimes. ?

I will double check again, I hope that's the case and try an autometer tach just to make sure it's all good. Thanks for the help guys.

When you install a TH350 in an F-body the dipstick will read incorrectly as to the angle of the trans the f-body engine is set up to have the crankshaft level and the orginal use of the TH350 was at a 5 deg downward angle so do not count on the dipstick for correct reading

Great post, and very helpful info. I just bought a Yank 4000 stall for my th400 install, will I have the same issue, or is the th400 designed to sit more level like the f-body?

On the Th 350 and Th400 the fill line will be the parting surface between the pan and case when the trans pan gasket area sets level to the ground, your fill mark on dipstick would be correct at this point and can be marked for future readings

Ok fluid looks and smells fine, level is good, hooked up the tach, shoots to 6k whenever I go full throttle. I'm not sure what else to check for other than something is wrong with the converter, trans was fine before with tight nitrous stall.

What does it stall to on your T-Brake?

When you hit 6000 rpm does it hold that for a while, then pull on up to redline? Is this NA?

Maybe the converter came in higher stall than expected and you are pushing through it.

Thanks for the call and we look foward to helping you with your problem.