Hello there! My question is related to a.

Hello there! My question is related to a transmission failure on my car which is a 1992 3000 GT SL Automatic trans., And the problem with it is that the transmission is missing gears which it means I only feel the third, reverse and neutral changes in the car, so there is not sense or feeling whatsoever of the first and second gears. Because of the missing gears, my car just launch on D way too slow in order to gain speed; also when going over 50miles/h I noticed the rpm increases way too much and after 30 minutes tops of driving at highway speeds, it start overheating. It is lacking power in general, so I wonder. What is going on with it since I already replaced the Trans, but the problem is still the same? :O