Adjustments Affecting Tooth Contact

Two adjustments can be made which will affect the tooth contact pattern: backlash and position of drive pinion gear (23) in the rear axle housing. The effects of bearing preloads are not readily apparent on hand-loaded tooth contact pattern tests.

Backlash is adjusted by means of differential bearing shims (24). They move the entire differential closer to or farther from the drive pinion gear (23). Bearing shims (24) are also used to set the differential bearing preload. If the thickness of the right bearing shim (24) is increased, along with decreasing the left shim thickness, backlash will increase. The backlash will decrease if the left shim thickness is increased, along with a decrease in right shim thickness.

The position of the drive pinion gear (23) is adjusted by increasing or decreasing the shim thickness between the drive pinion gear head and race of the differential drive pinion gear inner bearing. The drive pinion gear shim (19) is used in the rear axle to compensate for manufacturing tolerances. Increasing shim thickness moves the drive pinion gear (23) closer to the centerline of the differential ring gear (20). Decreasing shim thickness moves the drive pinion gear (23) farther away from the centerline of the differential ring gear (20).