So this is my first attempt at restoring an old car, and I got my hands on an 86 trans am with a chevy 350 and 700r4 tranny. Ive had it for a little less than a month and it has been running like a dream. Until yesterday. The night before the shifting was smooth and I wasn't driving out of the ordinary at all...no racing/high revs. The next morning when I went for a drive, 3rd and 4th gear were gone, and the shift from 1st to 2nd wont happen until I get to around 4200 and let off the gas a bit. Today I pulled the pan; there was no metal flake or anything in the fluid, problem is, I am not a transmission guy and had no idea what I was looking at/for so I bolted it back up. I have read a few similar forums but I haven't been able to find anything all that helpful, so any information that you guys might have would be a godsend to me

 

I had a similar problem. I turned out the gasket on one of the internal working parts, on the 1-2 accumulator piston, was incorrectly installed at the factory, and finally blew, causing the same symptoms. I had to have the transmission rebuilt, lucky me I know a tranny specialist and he redid mine, with new parts and a corvette servo and re-adjusted valve springs for $750.00