A common problem of the Trac-Lok® differential is a chatter noise when turning corners. Before removing the unit for repair, drain, flush and refill the axle with the specified lubricant. Add a container of Mopar Limited Slip Additive after repair service or during a lubricant change.After changing the lubricant, drive the vehicle and make 10 to 12 slow, figure-eight turns. This maneuver will pump lubricant through the clutches. This will correct the condition in most instances. If the chatter persists, clutch damage could have occurred.The differential can be tested without removing the differential case by measuring rotating torque. Make sure brakes are not dragging during this measurement.Place blocks in front and rear of both front wheels.Raise one rear wheel until it is completely off the ground.Engine off, transmission in neutral, and parking brake off.Remove wheel and bolt Torque Check Tool 6790 (1) or equivalent tool to studs.Use torque wrench (2) on Torque Check Tool (1) to rotate wheel and read rotating torque.If rotating torque is less than 41 N·m (30 ft. lbs.) or more than 271 N·m (200 ft. lbs.) on either wheel the unit must be replaced.