Have a 99 F350 with about 220 on the clock, its a repo truck and we just put a plow on it. It has a ATS Stage 5 TC in it. Well when you put in reverse it doesnt have any stall to it, it just feels like it locks and wont move that well. If you put it in any other foward gear its fine. What could this be?

 

It could be low fluid, a loose internal filter, worn seals, a bad pump.....