Ok this trans has had a shift kit installed and was put in the car. The trans worked fine before the shift kit and install. The car will work fine in reverse but when you put it in drive it wont move unless you rev the motor then it will barely move. The guy that put the trans in said that it is because the torque converter didnt get locked into the third stage when it was installed. Has this happened to anyone before or should I be looking for other problems?