Differential Assembly: Description and Operation

Fig. 1 Differential assembly cross sectional view:

Fig. 1 illustrates the type rear drive axle assembly used on Buicks. When necessary to overhaul any of these units, refer to the Rear Axle Specifications table in this chapter.
In this rear axle, Fig. 1, the drive pinion is mounted in two tapered roller bearings which are preloaded by a collapsible spacer. The pinion is positioned by shims located between a shoulder on the drive pinion and the rear bearing. The front bearing is held in place by a large nut.
The differential is supported in the carrier by two tapered roller side bearings. These are preloaded by inserting shims between the bearings and the pedestals. The differential assembly is positioned for proper ring gear and pinion backlash by varying these shims. The ring gear is bolted to the case. The case houses two side gears in mesh with two pinions mounted on a pinion axle which is anchored in the case by a spring pin. The pinions and side gears are backed by thrust washers.