you could have stripped the spur gear or dislodged the pinion. Take the gear cover off and check the pinion and spur. If it is the pinion gear (gear coming off the motor) make sure the little screw attaching it to the motor is not stripped. If it is replace it and re-apply with locktite.
-Electrical wiz-Let me check your shorts.....that came out wrong
Ofna Hyper 10sc
T-maxx O.S .18tm