Differential Assembly: Description and Operation

The rear axle assembly has the following features:
- An integral-type housing hypoid gear design (center of the pinion set below the centerline of the ring gear).
- The hypoid differential ring gear and pinion consists of a ring gear and an overhung drive pinion which is supported by two opposed tapered roller bearings.
- Pinion bearing preload is maintained by a collapsible spacer on the differential pinion shaft and adjusted by the pinion nut.
- The rear axle housing consists of a cast center section with two steel tube assemblies and a stamped differential housing cover.
- The differential housing cover uses silicone sealant as a gasket.
- The differential pinion shaft is retained by a threaded differential pinion shaft lock bolt assembled to the differential case
- The differential case is mounted in the rear axle housing between two opposing differential bearings that are retained in the rear axle housing by removable bearing caps
- Use SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL or equivalent meeting Ford specification WSP-M2C197-A for 4.0L SOHC and 4.0L EI with a conventional differential.
- Use SAE 75W-140 High Performance Rear Axle Lubricant F1TZ-19580-B or equivalent meeting Ford specification WSL-M2C192-A for 4.0L SOHC and 4.0L EI with a limited slip differential and 5.0L.
- Differential bearing preload and ring gear backlash are adjusted by differential bearing shims located between the differential bearing cups and the rear axle housing.
- Rear axle identification is on an embossed metal tag bolted to the axle housing cover.