Eaton Locking Differential Chatter Shudder Noise On Turns - keywords bind grab grind

This PI was superseded to update model years. Please discard PIP4054.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Customers may comment on a chatter or shudder from the rear axle on vehicles equipped with an Eaton locking differential. This condition would be noticed in parking lot maneuvers, turning, or during locking differential engagement and may be more noticeable when the differential is hot. Locking differential clutch chatter may be causing this concern.

Note 1: This does not apply to vehicles equipped with RPO QS4 (Quadrasteer) which is part of option package NYS. Quadrasteer vehicles use Dana axles and have a different fluid requirement.

Note 2: This PI does not apply to vehicles equipped with a RPO G86 limited slip differential. For the G86 differential reference the latest version of PIP3911.

If differential clutch chatter is encountered in a vehicle equipped with an Eaton locking differential, flush, drain and refill the differential with new synthetic fluid, use the fluid part number listed in SI for the vehicle currently being worked on. If the condition returns replace the rear differential clutch plates and refill the differential with new synthetic fluid, use the fluid part number listed in SI for the vehicle currently being worked on. Refer to eSI for clutch plate replacement and set up procedures.

Note 1: Eaton locking differentials used in 10.5" rear axles are equipped with steel clutch plates. It is a design characteristic of these steel clutch plates to exhibit more clutch chatter than other models.

Important: Installing any friction modifier causes the clutch pack in the locking differential to slip and miss engagement. A fluid flush can often remove debris that is a contributor to clutch chatter. Adding friction modifier additive can cause a loss of locking differential functionality.

Note 2: On Quadrasteer equipped vehicles, simply flush the rear axle and refill with the fluid listed in SI document 793720 under the steerable application.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.