Pinion Ring Gear Variation Number
Pinion Ring Gear Variation NumberNOTE: If so equipped, replace the rear axle drive pinion shaft oil slinger if it is bent or mutilated.
NOTE: The ring gear and pinion is only available in a matched set. Matching numbers are etched on both the ring gear and pinion for verification. If installing a new ring gear and pinion, verify the numbers of each ring gear and pinion before proceeding with assembly. The end of the pinion with the etched figures is known as the "button" end.
NOTE: Use the gear contact pattern method to make sure the final pinion position is valid.
1. Shim the pinion as follows:
^ On the button end of each pinion, there is etched a plus (+), a minus (-) or a zero (0) number, which indicates the best running position for each particular ring gear. This dimension is controlled by the shimming behind the inner pinion bearing cup (the backface).
^ For example, if a pinion is etched m+8 (+3), this pinion requires 0.08 mm (0.003 inch) less drive pinion position shims than a pinion etched "0". This means by removing drive pinion position shims, the mounting distance of the pinion is increased, which is what an m+8 (+3) indicates. Or if a pinion is etched m-8 (-3), add 0.08 mm (0.003 inch) more shims than would be required if the pinion were etched "0". By adding 0.08 mm (0.003 inch) shims, the mounting distance of the pinion is decreased, which is what an m-8 (-3) indicates.
2. Measure between the centerline of the ring gear to the backface of the drive pinion. The distance must be 147.6 mm (5.812 inches).
3. If the old ring gear and pinion is to be reused, measure the old drive pinion position shims and build a new pack of shims to this same dimension. If an oil slinger is used in the rear axle assembly, it is considered part of the shim pack.
^ To change the pinion adjustment, shims are available in thicknesses of 0.08, 0.13 and 0.25 mm (0.003,0.005 and 0.010 inch).
^ Measure each shim separately with a micrometer and add together to get the total shim pack thickness from the original buildup.
New Pinion Conversion Chart (Metric):
4. If a new ring gear and pinion is being used, notice the (+) or (-) etching on both the old and new pinion and adjust the thickness of the new shim pack to compensate for the difference of these two figures.
^ For example, if the old pinion reads m+5 (+2) and the new is m-5 (-2), add 0.10 mm (0.004 inch) drive pinion position shims to the original shim pack.