Dont know the best way of wording this but basicly when im accelerating from say 40mph and i hit the gas with a fair amount of force to get it going up to a faster speed quickly the truck makes a loud thump sound and kinda just staggers for a second then takes off. now if im going slow enough or im not moving i can smash the peddle and nothing happens. Anyone got any ideas on where i may need to start looking to fix the issue. no dummy lights or anything like that are on also. its only been doing this for about 3 weeks and only if i give it good amount of gas once i hit like 40-50 if i just ease it up to speed it doesnt seem to do it.