Determining Correct Pinion Starting Shim

1. If original ring and pinion are being installed, use original shim. If new parts (gear set) are being installed, use following steps to determine best starting shim thickness.
2. Check numbers etched on drive pinion and ring gear. Measure thickness of original pinion shim. Note variance number on pinion gear. See Figure . Note where old and new pinion marking columns intersect on chart. See Fig 1 .
3. Intersecting figure represents amount needed to add or subtract from original shim. For example, if old pinion is +1 and new pinion is -3, intersecting figure is +.004" (+.10 mm). Add this amount to original shim. If old pinion is -3 and new pinion is -2, intersecting figure is -.001" (-.025 mm). See Fig 1 . Subtract this amount from original shim.

Fig 1: Pinion Variance Chart

Courtesy of CHRYSLER CORP.