Drive Pinion Installation

Drive Pinion Installation

Two separate adjustments affect contact between the ring gear and drive pinion: pinion depth and pinion to ring gear backlash. Refer to Adjustments.






Pinion depth is controlled by a shim (with a selective thickness) located between drive pinion head and inner differential pinion bearing and an oil baffle located between the rear drive pinion bearing cup and carrier bore.






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

On the button 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 thickness of the baffle between the inner pinion bearing cup and carrier bearing bore and the thickness of the selective shim between the pinion head and inner pinion bearing. Any pinion depth change is made by changing the thickness of the selective shim. Refer to the charts shown below.

- For example, a drive pinion that is etched "0" should be 96.85mm (3.813 inch) from the centerline of the ring gear to the back face of the pinion. A pinion that is etched +3 (m+8) should be 96.93mm (3.816 inch) from the ring gear centerline. If the baffle thickness remains the same, then the +3 (m+8) pinion requires a selective shim that is 0.08mm (0.003 inch) thinner than the selective shim used with the "0" etched drive pinion.

If the original gearset is being re-used, measure the original baffle and selective shim. If either the baffle or selective shim needs to be replaced, use a new one of the exact same thickness.

If a new gearset is used, notice the plus (+), minus (-), or zero (0) etching on both the original and the new drive pinion and adjust the thickness of the new selective shim according to the charts shown below.

- For example, if the original pinion is etched +4 (m+ 10) and the new pinion is etched "0", then the new selective shim is 0.08mm (0.004 inch) thicker than the original selective oil slinger.











If the original pinion is etched "0" and the new pinion is etched + 3 (m+8), the new selective shim should be 0.08mm (0.003 inch) thinner than the original shim.