I have an 88 with the 4+3, has about 80,000 miles on it. I have been chasing a problem woth it not engaging when its suposed to (computer tells it too, light on dash turns on. Also when i press the button, light turns on) and sometimes just engaging and dissengaging on its own all while the indicator light is on. I always get the car to operating temp, and i live in a residential neighborhood so after its up to temp i have a short slow drive to the main road. Once im there i expect in second gear at a normal acceleration it should engage, sometimes it will, sometimes it wont, (indicator light turns on).i have done a lot of homework and investigating. I have changed fluid and filer. I found i had a faulty relay and replaced it, I have traced power through wires and switches and landed on the overdrive pressure switch and the solenoid not always responding when power is sent to them. I would like to repace them while i have the pan off.

Where can i find these parts?!

I have searched GM, Ecklers, corvette central, corvette america, rockauto, corvette guys, zip corvette, paragon, local auto parts places (Napa, Oriellys and a few more) with no luck.

Thank you for any hints or recommendations!

I have called a few, including the chevy dealer. Responses were “we wont work on thos transmissions”, or “bring the car in and we will look and see if we can figure out the problem”. Which I explained in not looking for them to tell me the issue, I'm looking for parts. I offered to pay them some money to give me the info to contact the parts dealer. But that was a no go.

I have done a flush and filter change and filled it. More than once. Still does it. I have put a few ounces of sea foam transmission fluid in it as well. No difference. Its electrical, but I cant find the two parts that arent acting correctly. I checked the 5speeds.com and no luck there.