Pinion Depth Variance
WARNING: This page is about a different car, the 2008 Dodge Magnum, 2008 Dodge Charger, and 2008 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
Identifying numbers for the ring gear and pinion are marked on the pinion (1). See Fig 1. A plus (+) number, minus (-) number or zero (0). The pinion depth variance/deviation (1) is the amount the depth varies from the standard depth setting of a pinion marked with a (0). The standard depth provides the best gear tooth contact pattern.
The pinion depth is set by selecting the shim (1) that fits between the pinion housing and the axle housing. See Fig 2.