hi. im new to rc. well getting back into it. i bought my slash used and have had some problems with it. blew out the bearing in the rear so far. now this. when driving the truck i stop at the bottom of a small hill of dirt. then start to go up just a little the truck stops then it trys to again then stops and trys again then it will just roll backwards back down the hill. it goes fine on flat ground and goes up the hill with a running start. im baffled. is my speed control on its way out? i should also say that the remote is a losi spectrum 2.4. any help would be great