HYPOID Gear Backlash
WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
Adjust the backlash by turning the side retainer in the RH side case.
ST 18630AA010 WRENCH COMPL RETAINER
NOTE:
Each time the side retainer rotates by one notch (A), the backlash changes by 0.05 mm (0.0020 in).