Possible Transmission Issues?

I am currently driving a 1981 Chevette with a 1.6 L 98 CID L4 SOHC. About 6 months ago I started experiencing an issue where I couldn’t accelerate on turns, it would just rev the engine up, when i straighened out it would drive normally again. I thought I resolved this issue when I drained the transmission fluid replaced the transmission filter and refilled it. Now it started doing the same thing last night but to a worse degree. This morning when i tried to drive it, it started fine, but when i shifted the car didn’t shift at all just acted as if the gear shift had never been moved (It is an automatic). I checked the fluid last night and I thought it was OK but it was really dark so I will check it again when I get off Work but does anyone have any ideas on what could be happening here?

Yes, make sure that the fluid level is up to the ‘hot full’ level. Warm the car up on a level pad (15 minutes), shift through all the gears, return to park, and with the engine running measure the fluid level. If it is low bring it up and check again.

If the problem continues, you should probably have this looked at by a transmission technician. He/she should at least do a line pressure check at idle, drive, reverse, and stall if can be achieved. You don’t mention how many miles are on this transmission so I will assume that there are a lot on a 27 year old car. It may be time to overhaul the transmission because seals get hard as they age and frictions just wear out with the number of shifts.

If you can find one, a low mileage used transmission might be an option to having yours rebuilt. But, consider that a used transmission is going to be about as old chronologically as yours so it might not be a bargain.