Ring Gear: Service and Repair

Two separate adjustments affect drive pinion and ring gear tooth contact: pinion depth and pinion to ring gear backlash.

Fig. 5 Drive Pinion Installation:

Pinion depth is controlled by a selective thickness oil slinger located between drive pinion head and inner pinion bearing cone and an oil baffle located between inner bearing cup and carrier bore, Fig. 5.

Pinion to ring gear backlash is controlled by preload shims on model 28-IFS and 28-2 or a selective spacer on model 35-IFS, located between the differential bearing cup and carrier.

During pinion depth adjustment, the size of the selected thickness of oil slinger and baffle controls pinion position. Increasing oil slinger thickness moves pinion toward ring gear (-). Decreasing oil slinger thickness moves pinion away from ring gear (+).

Fig. 6 Ring And Pinion Identification:

On the button of each drive pinion is marked a plus (+), a minus (-) or a zero (0), Fig. 6. These markings indicate the position for each gear set. The position is determined by thickness of baffle between inner pinion bearing cup and carrier bearing bore and thickness of selective oil slinger between pinion head and and inner pinion bearing. Any pinion depth change is made by changing thickness of selective oil slinger.

If the original gear set is being re-used, measure original baffle and selective slinger and replace with exact same size, if necessary.

Fig. 7 Drive Pinion Adjusting Shim Thickness Chart:

Fig. 8 Drive Pinion Adjusting Shim Thickness Chart (Metric):

If a new gear set is being used, notice the plus (+), minus (-) or zero (0) etchings on both original and new drive pinion and adjust thickness of new selective oil oil slinger according to charts in Figs. 7 and 8.