Recently bought a used '05 Chevy 2500hd duramax with an Allison 5 speed. I checked the dipstick 3 times cold. Same reading every time. Up past the hot mark. Any reason why there would be excess fluid in the transmission from the previous owner? Does it help when towing at all? It's kinda of a long distance between the hot and cold marks. Should I try to drain some of that? How much fluid does the dipstick dip into, or how much fluid is it from the top of the hot mark to the top of the cold mark?