i have an 04 gtp comp g with 134k miles. when i put it into drive nothing happens, engine just revs up. When i put it in manual mode it will kick into first gear but when i hit the gas it slips. once i get it moving and into second gear i can then put it back into drive and it will go into 3rd and 4th fine. I was low on fluid so i filled it up. I am assuming that is why i am having this issue now. Any idea's on maybe what part is bad? i was told it could be the forward band??? i really don't want to do a complete rebuild if i don't have to.