Differential Assembly: Description and Operation

Rear Drive Axle and Differential
The rear axle assembly contains the following features:
^ An integral-type housing hypoid gear design which has the centerline of pinion set below the centerline of ring gear.
^ A hypoid ring gear and pinion, consists of a 203 mm (8.0 inch) diameter ring gear and an overhung drive pinion which is supported by 2 opposed tapered roller bearings.
^ Pinion bearing preload is maintained by a drive pinion collapsible spacer on the pinion shaft and adjusted by the pinion nut.
^ A rear axle housing assembly which consists of a differential carrier and a cast-aluminum rear differential housing cover.
^ A differential housing cover which uses silicone sealant rather than a gasket.
^ A differential case which is a 1-piece design with 2 openings to allow for assembly of internal components and lubricant flow.
^ A differential pinion shaft which is retained by a threaded differential pinion shaft lock bolt assembled to the differential case.
^ A differential case which is mounted in the rear axle housing between 2 opposed differential bearings.
^ Differential bearings which are retained in the rear axle housing by 1 removable bearing cap.
^ Differential bearing preload and ring gear backlash which are adjusted by differential bearing shims located between the differential bearing cup and the rear differential housing.
^ The use of a pinion depth gauge is required for correct differential ring gear and pinion adjustment.
^ The halfshafts are held in the differential case by a circlip that is located on the inboard CV joint stub shaft. When each halfshaft is installed, the circlip engages a groove in the differential side gear.

The rear drive axle operates as follows:
^ The rear axle drive pinion receives power from the engine through the transmission and driveshaft.
^ The pinion gear rotates the ring gear, which is bolted to the differential case outer flange.
^ Inside the differential case, 2 differential pinion gears are mounted on a differential pinion shaft which is pinned to the differential case.
^ These differential pinion gears are meshed with the differential side gears to which the halfshafts are splined.
^ As the differential case turns, it rotates the halfshafts.
^ When it is necessary for 1 wheel and halfshaft to rotate faster than the other, the faster turning differential side gear causes the differential pinion gears to roll on the slower turning differential side gear. This allows differential action between the 2 halfshafts.