Rear Axle Pinion Seal Leak - keywords fluid differential leak pinion repeat

This PI is being superseded to update model years and recommendations. Please discard PIP3671D.

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

The rear axle pinion seal may experience a fluid leak condition. During seal replacement, the new seal may still leak as work on the vehicle is being completed. It is possible that when replacing the seal, the rear axle lube is seeping through the pinion bearings. The lube then gets past the rubber seal and gets trapped behind the metal "dust shield" before the pinion yoke is installed. When the dealer installs the pinion yoke, the trapped fluid is squeezed out and gives the illusion of a continued leak.

Inspect the new seal for the presence of the internal "garter" spring and make sure it is there. If not, use a seal that does have it. Also inspect the new seal for metal contamination in the grease used to lube the seal lip. If there is any contamination, discard the seal and use only a debris free seal that is supplied with grease.

All stock of the pinion seal at SPO as of March 15th, 2006 has been inspected and should be free of these issues.

When replacing the pinion seal, make sure that the pinion bore is free of excess fluid that could get trapped before the yoke is installed. Install the new seal and the original yoke promptly, before excess fluid seeps into the area. It may be necessary to drain some or all of the axle fluid to assure that the pinion bore remains free of fluid during seal installation.

This should prevent the lube from being trapped behind the dust shield.

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.