91 corolla transmission problems

[Bmastridge]

I purchased a 91 Corolla from someone who had the motor only changed after a major failure. After the new motor was put in, it would drive fine for a short period, then not go into gear. I changed out the transmission with a known good one, it drove fine the first time, now does the same thing, no reverse or drive in any gear. seller said there were no transmission problems prior to the engine change, and the guy did a half ass job with changing the motor, which I have corrected. Any thoughts would be appreciated.

Thanks

P.S. It's an automatic

[SCT]

Check the trans fluid and the shifter cable. If that's all good, then it could be bad torque converter OR the transmission (again).