Why does the trans shift hard and jerk the car when heated up? on 2000 Pontiac Grand Prix

Ok heres what I've been dealing with I picked up the car used last august car drove great did everything I needed it to do. About two weeks later I'm driving the car around a lot I'd say after driving for about 3-4 hours without much of a break, the car when the transmission goes to upshift it will hesitate and stutter jerking the car and you can feel it, then it slams the car into the next gear really hard

by in Vassar, MI on April 09, 2013
2 answers
ANSWER by on April 09, 2013
scan codes and post so we can adv
ANSWER by on April 09, 2013
bring it to a tranny shop for diagnostic run. tranny tech. will advise.