Differential Assembly: Description and Operation

Fig. 1 Final drive assembly exploded view:

The final drive unit consists of a housing assembly which is secured to the transmission by six bolts and supported by a bracket attached to the engine. The housing contains a hypoid ring gear and pinion with the pinion set above the ring gear center line and a differential case assembly. The case contains two internally splined side gears and two differential pinions which are backed by steel thrust washers, and a pinion idler shaft, Fig. 1.
The pinion gear is mounted in the housing on two tapered roller bearings and is splined directly to the transmission output shaft. Pinion bearing preload is maintained by a collapsible collar positioned between the pinion bearings while pinion depth is adjusted by means of a shim placed between the pinion head and inner bearing.
Torque from the drive pinion is transferred to the ring gear which is attached to the differential case. The case is mounted in the housing on two tapered roller side bearings. Shims are used both to maintain side bearing preload and to adjust ring gear and pinion backlash.