my 99 buick regal gs has a problem with tranny slipping in od and i think in 3rd somtimes.. it wont do it if the car is cold but after it warms up if im just driving and step in the gas a bit, it will slip for a sec then catch and go.. also at cruising speed it seems like it shifts alot between 3rd and OD.. so what im asking is. Is there anyway to fix this w/o a rebuild some soliniod or somthing i have already changed the filter. anyone have any ideas?