Drive Pinion Installation

Two separate adjustments affect tooth contact of the drive pinion and ring gear:

• pinion depth (location)
• backlash

The pinion locating shim is installed between the differential pinion bearing (4630) and the head of the pinion gear.

This shim pack and inner oil slinger and oil baffle control the position of the pinion.

• Increasing shim thickness moves the pinion toward the ring gear.
• Decreasing shim thickness moves the pinion away from the ring gear.

Differential ring gear and pinions are supplied in matched sets with standard or metric markings.

On the face of each drive pinion is marked a plus figure (+), a minus figure (-) or a zero (0). These figures indicate the position for each gearset. The position is determined by the amount of drive pinion shims between the pinion bearing cup and carrier bearing bore, or if selective shim is used, between the inner pinion bearing cone and pinion gear head. Refer to the following charts.

Old Pinion Marking	New Pinion Marking (English)
	-4	-3	-2	-1	0	+1	+2	+3	+4
+4	+0.008	+0.007	+0.006	+0.005	+0.004	+0.003	+0.002	+0.001	0
+3	+0.007	+0.006	+0.005	+0.004	+0.003	+0.002	+0.001	0	-0.001
+2	+0.006	+0.005	+0.004	+0.003	+0.002	+0.001	0	-0.001	-0.002
+1	+0.005	+0.004	+0.003	+0.002	+0.001	0	-0.001	-0.002	-0.003
0	+0.004	+0.003	+0.002	+0.001	0	-0.001	-0.002	-0.003	-0.004
-1	+0.003	+0.002	+0.001	0	-0.001	-0.002	-0.003	-0.004	-0.005
-2	+0.002	+0.001	0	-0.001	-0.002	-0.003	-0.004	-0.005	-0.006
-3	+0.001	0	-0.001	-0.002	-0.003	-0.004	-0.005	-0.006	-0.007
-4	0	-0.001	-0.002	-0.003	-0.004	-0.005	-0.006	-0.007	-0.008

Old Pinion Marking	New Pinion Marking (Metric)
	-10	-8	-5	-3	0	+3	+5	+8	+10
+10	+0.20	+0.18	+0.15	+0.13	+0.10	+0.08	+0.05	+0.03	0
+8	+0.18	+0.15	+0.13	+0.10	+0.08	+0.05	+0.03	0	-0.03
+5	+0.15	+0.13	+0.10	+0.08	+0.05	+0.03	0	-0.03	-0.05
+3	+0.13	+0.10	+0.08	+0.05	+0.03	0	-0.03	-0.05	-0.08
0	+0.10	+0.08	+0.05	+0.03	0	-0.03	-0.05	-0.08	-0.10
-3	+0.08	+0.05	+0.03	0	-0.03	-0.05	-0.08	-0.10	-0.13
-5	+0.05	+0.03	0	-0.03	-0.05	-0.08	-0.10	-0.13	-0.15
-8	+0.03	0	-0.03	-0.05	-0.08	-0.10	-0.13	-0.15	-0.18
-10	0	-0.03	-0.05	-0.08	-0.10	-0.13	-0.15	-0.18	-0.20

If the old ring and pinion shim pack is used, measure the slinger and baffle and each shim separately and add each shim measurement to total the original measurement. Replace the old shims with new shims that equal this measurement.

If a new ring gear and drive pinion is being installed, note the plus (+), minus (-) or zero (0) marking on the button of the pinion. Refer to the charts. Add or subtract shims, according to the chart to compensate for differences between the old and new pinion.

For example, if a new pinion is marked "positive" +3 (+8 metric) and an old pinion is marked "0," then 0.008mm (0.003) less shim pack thickness is required between the inner differential pinion bearing and the pinion head.

A new ring gear and drive pinion is always installed as a matched set and never separately. Make sure that the same matching number appears on both the drive pinion and ring gear.

Install the correct shim pack of the drive pinion and place the pinion in the carrier. Check pinion depth.