INSPECTION OF DIFFERENTIAL OPERATION INSPECT DIFFERENTIAL OPERATION (a) After completing work, block the front wheels and jack up one of the rear wheel. (b) Rotate the rear wheel 3 - 6 times to break it in. (c) Check that the wheel turns smoothly. HINT: If the wheel can not be turned or if it turns with a drag, re-disassemble the differential case and select a different size adjusting shim. (d) Check the opposite wheel in same procedure.