2008 Cadillac STS Differential

The procedure is to install the drain plug to the differential, clean any dirt from around the differential fill plug, remove the fill plug from the differential, fill the differential with 75W90 synthetic axle lubricant, GM P/N 12378261 (Canadian P/N 10953455) or equivalent, inspect the gear lubricant level to ensure it is even with the bottom of the fill plug hole to no lower than 6 mm (0.25 in) below the opening, install the fill plug to the differential, lower the vehicle.

The procedure is to inspect the bearing rollers and races, inspect the bearing rollers and races for heat discoloration, inspect for bent bearing cages, and inspect for damaged bearing cages.

The procedure is to clean the differential housing in the solvent, clean and inspect the differential housing for the following: the mounting bolt threads, the case cover bolt hole threads, the O-ring sealing surface for nicks or burrs, the drain plug hole threads, the axle seal area, the pinion bolt hole threads, the bushing bore, and cracks in the housing, if removed.

The procedure is to raise and support the vehicle, clean any dirt from around the differential drain plug, position a drain pan under the drain plug, remove the drain plug from the differential and drain the fluid.

The procedure is to raise and support the vehicle, clean any dirt from around the differential fill plug, remove the fill plug from the differential and drain the fluid, check the differential fluid level, it should be even with the bottom of the fill plug hole to no lower than 6 mm (0.25 in) below the opening, add new fluid if necessary, fill the differential with 75W90 synthetic axle lubricant, GM P/N 12378261 (Canadian P/N 10953455) or equivalent, install the differential fill plug to the differential, lower the vehicle.