Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Raise the rear of the unit, and turn one wheel by hand, see if the other wheel turns in opposite direction. If it does rear end is ok. At the same time , look at the wheel to axle joint, If the key between axle and wheel on the right side has sheared, you will lose drive and locking the differential will let the left wheel pull!
Right axle shaft broken or sheared?