something not right there,Im on standard motor, i snap my rope before mine stalls and it drags my truck over anything. . the splined shaft motors are the late type, have you check that the winch is not full of rust and has oil in it, when you took cap of end of the motor were all the brushed free and making a good contact? and how long were they? could also check earths always over looking but is a must! and lead size is up to the job