Differential Assembly: Description and Operation

Rear Drive Axle and Differential

The 8.8-in rear axle assembly contains the following features:

- integral-type housing hypoid gear design with the centerline of the pinion set below the centerline of the ring gear.
- hypoid ring and pinion, which consists of a ring gear and an overhung drive pinion which is supported by 2 opposed pinion bearings.
- pinion bearing preload that is maintained by a drive pinion collapsible spacer on the pinion stem and adjusted by the pinion nut.
- differential housing assembly of a cast center section, 2 steel tube assemblies, a steel differential housing cover and a Watts linkage assembly.
- differential housing cover that uses a silicone sealant rather than a gasket.
- differential case that is a 1-piece design with 2 openings to allow for assembly of internal components and lubricant flow.
- differential pinion shaft that is retained by a differential pinion shaft lock bolt assembled to the differential case.
- differential case that is mounted in the rear axle housing between 2 opposed tapered roller differential bearings.
- differential bearing cups that are retained in the rear axle housing by removable bearing caps.
- differential bearing preload and ring gear backlash adjusted by the differential bearing shim located between the differential bearing cup and the rear axle housing.
- differential which comes in either the conventional open style or a Traction-Lok(R) design.
- semi-floating axle shafts that are held in the housing by U-washers positioned in the slot on the axle shaft splined end.
- U-washers that fit into a recess in the differential side gears within the differential case.

The rear axle assembly receives rotational input from the driveshaft through a piloted pinion flange. The drive pinion drives the ring which is bolted to the differential case. The design of the differential allows the side gears in the case to rotate at different speeds. The axle shafts are splined to the side gears permitting the vehicle to manipulate corners without sliding the inside tire. The weight of the vehicle is carried through the axle shaft bearing located in the tubes of the axle housing.