Adjustments Affecting Tooth Contact

Two adjustments can be made which will affect the tooth contact pattern. These are backlash and pinion depth. The effects of bearing preloads are not easily. seen on hand loaded teeth pattern tests. These adjustments should be within specifications before proceeding with the backlash and the drive pinion adjustments.

It may be necessary to adjust both pinion depth and the backlash to obtain the correct pattern.

Pinion depth is adjusted by increasing or decreasing the shim thickness between the pinion head and the inner race of the rear bearing. The shim is used in the differential to compensate for manufacturing tolerances. Increasing the shim thickness will move the pinion closer to the centerline of the ring gear. Decreasing the shim thickness will move the pinion farther away from the centerline of the ring gear.

Backlash is adjusted by means of the side bearing adjusting sleeves which move the entire case and ring gear assembly closer to, or farther from the drive pinion. (The adjusting sleeves are also used to set side bearing preload). To increase backlash turn the left sleeve in and turn the right sleeve out an identical amount. To decrease backlash, turn the right sleeve in and turn the left sleeve out an identical amount.

It is important that the contact pattern be centrally located up and down on the face of the ring gear teeth.