Leaks

Most rear axle leakage conditions can be corrected without a teardown. However, it is important to clean the leaking area enough to identify the exact source of the leak.

A plugged jiggle cap vent will cause excessive seal lip wear due to internal pressure buildup. When a leak occurs, check cap by pressing down on it with index finger. If the cap moves up and down freely, it is working properly. If it does not move freely, it must be replaced.

Check axle lubricant level. Lubricant should be 9/16 inch below bottom of filler hole.

Drive Pinion Seal

When the drive pinion seal leaks, it is usually because of improper installation, or because of poor quality of the seal journal surface. Any damage to the seal bore (dings, dents, gouges, etc.) will distort the seal casing and allow leakage past the outer edge of the seal.

Pinion Nut

Some models may experience oil leakage past the threads of the pinion nut. The condition can be corrected by removing the nut and applying pipe sealant with Teflon part No. D8AZ-19554-A or equivalent on the pinion threads and nut face. Ensure the correct procedure for setting the bearing preload is followed when the nut is installed.

Holes In Casting

The differential carrier may leak through small pockets in the metal. These pockets (casting leakage) are caused by gas bubbles in the casting process and are known as a porous condition or porosity.

Because there is always the danger of changing the axle's sound characteristics if torn down to replace the carrier, servicing the porosity is preferable. There are two recommended types of service procedures outlined below for this condition.
1. Peen a small amount of body lead into the hole, then seal the pocket with Epoxy Sealer Metallic Plastic part No. C6A7-A9554-A or equivalent.
2. In larger pockets, drill a shallow hole and tap it for a small setscrew. Install the setscrew and seal it over with Epoxy Sealer Metallic Plastic part No. C6A7-A9554-A or equivalent.

Axle Vent

There have been some occurrences of lubricant leaking through the axle vent. This may be caused by a clogged or sticking axle vent cap. If this is the case, the vent assembly should be replaced, use Stud and Bearing Mount part No. EOAZ-19554-BA or equivalent on threads of vent to ensure retention.