I installed a new trans (with original valvebody and techm) last month into my c6 and tried to test it before i even took it off the jack stands to immeadiately find there was no reverse. Wouldnt even clunk or feel like it was engaged. Foward gears seemed good. Well after getting a new valvebody and techm installed then flashed by gm, reverse is still nowhere to be found and trans wont upshift out of first and even slipped so bad to point of no foward movement at all. The only time the car was driven under its own power was after the new techm install and flash. Even had a whirring noise right before it quit moving. Torque converter was cut and cleaned prior to install and lines flushed. I made sure to have 1/8th inch clearance between the pads and flexplate. The fluid still looks clean after i dropped the pan with no chunks to be seen. Was there something i did wrong? Did i not put enough fluid in the converter? Could that make reverse not engage but drive work? I also overfilled the atf buy a solid qt as recommended. Where does the shifter detent need to set? Looking for any help i can get here guys. Getting ready to take the trans back to the builder and am halfway expecting him to say he cant find anything wrong 🙄. Btw the converter is a precision 2800 lockup. For some reason i cant help but suspect it some how ran dry but idk if that would cause all of this. Really not trying to send it back again and wait another month. Ive owned this car for almost 4 months and only drove it for one of those. Its getting close to putting it away for winter soon. 😔 Thanks gents.

 

My Best
Am given to understand, when replacing cable. Both shifter and transmission need to be in neutral.

 

I feel your pain, I've had similar issues in the past, luckily not with my current corvette. I'm not sure how to help, but here's a bump in the hopes someone else will.

If the car is going into drive that means that the pump is working. This may be a dumb question, but to cover the basics, did you move the shifter through all the gears while it was warming up before checking the fluid level? If there is an air pocket in there that should help bring it out, then drain the excess fluid. I'm sure you followed the proper procedure, but I'd rather double check than assume.

 

aw yeah weve been through all the gears plenty of times and i even went thru the range multiple times with vise grips on the shaft to rule out any shifter/cable funny business. Im take the trans to the builder tomorrow so hopefully ill have some asnwers soon. Ive been thinking about the converter and even talked to the guy at precision and we concluded that even if the converter had failed (highly unlikey) it wouldnt cause reverse to not engage but allow drive. Even if the converter was low on fluid initially, the pump would fill it up quick enough. And the car never saw any road time anyways. Thanks for the reply tho

 

Drove the trans 4.5 hours out to the builder so he could tear it down and inspect it. Everything still looked brand new and no chunks or flakes in the oil. However though, he did find a sticking pressure regulator valve so we think that would definately cause my problems. Unfortunately tho, i think the last of fluid pressure has caused my newley cut and cleaned and restalled precision 2800 converter to start failing causing the steady whirring noise. Im very hesitant to put it back in as is and potentially wipe out a good trans. Im not really sure how i want to proceed here now.... kinda wanna get away from precision and go with a yank or circle d. Anybody have a lead on any in stock or a used one for sale?

 

I have circle D converter FS