Positive Traction Differentials: Testing

Positive traction differentials can be tested externally by raising 1 rear wheel, with transmission in neutral, and attempting to rotate wheel by hand. If wheel can be turned, differential should be repaired or replaced. Differential can also be tested by attaching a torque wrench to an axle shaft/side gear assembly (in vehicle/on bench). Turning torque wrench, while holding opposite axle shaft (or driveshaft)/opposite side gear stationary, should require up to 120 ft. lbs. for breakaway and 30-40 ft. lbs. to maintain rotation. See Figure and Figure.