Flange Yoke Seal

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

Leaks at the axle drive pinion seal originate for the following reasons:

Seal was not correctly installed
Poor quality seal journal surface

Any damage to the seal bore (dings, dents, gouges or other imperfections) will distort the seal casing and allow leakage past the outer edge of the axle drive pinion seal.

The axle drive pinion seal can be torn, cut or gouged if it is not installed carefully. The spring that holds the axle drive pinion seal against the pinion flange may be knocked out and allow leakage past the lip.

The rubber lips can occasionally become hard (like plastic) with cracks at the oil lip contact point. The contact point on the pinion flange may blacken, indicating excessive heat. Marks, nicks, gouges or rough surface texture on the seal journal of the pinion flange will also cause leaks.

A new pinion flange must be installed if any of these conditions exist.

Metal chips or sand trapped at the sealing lip can also cause oil leaks. This can cause a wear groove on the pinion flange and heavy pinion seal wear.

When a seal leak occurs, install a new seal and check the vent and the vent hose to make sure they are clean and free of foreign material.