Rear Axle - 8 1/4: Adjustments

General Information/Description / Rear Axle - 8 1/4 inch
Ring gears and pinions are supplied as matched sets only. The identifying numbers for the ring gear and pinion are etched/marked onto each gear. A plus (+) number, minus (-) number or zero (0) is etched/marked on the face or shaft of the pinion. This number is the amount (in thousandths of an in.) the depth varies from the standard depth setting of a pinion etched with a (0). The standard depth provides the best gear tooth contact pattern. Refer to Backlash and Contact Pattern Analysis for additional information.






Compensation for pinion depth variance is achieved with select shims. The shims are placed behind the rear pinion bearing.

If a new gear set is being installed, note the depth variance etched into both the original and replacement pinion. Add or subtract the thickness of the original depth shims to compensate for the difference in the depth variances.

Pinion Gear Depth Variance Chart:

Refer to the Depth Variance chart.

Note where Old and New Pinion Marking columns intersect. Intersecting figure represents plus or minus the amount needed.


Note the etched number on the face of the pinion gear head (-1, -2, O. +1, +2, etc.). The numbers represent thousands of an inch deviation from the standard. If the number is negative, add that value to the required thickness of the depth shims. If the number is positive, subtract that value from the thickness of the depth shim. If the number is 0 no change is necessary.