Fluid - Differential: Service and Repair

1. Raise and suitably support the vehicle.
2. Clean any dirt or foreign material from around the rear axle housing drain plug.
3. Remove the rear axle housing drain plug.
4. Ensure that the axle lubricant level is within the following range:
^ No higher than the bottom of the plug opening.
^ No lower than 15 mm (9/16 inch) below the plug opening
5. If necessary, add to or replace the axle lubricant. Use Synthetic 75W-90 gear lubricant (GM P/N 12378261), meeting GM specification 9986115 or equivalent.
6. If the vehicle has a limited slip differential, add 118 ml (4 fl. oz.) of limited slip differential additive.
7. Install the rear axle housing fill plug.
^ Tighten the rear axle housing fill plug to 35 Nm (26 ft. lbs.).

NOTICE: Refer to Fastener Notice in Service Precautions.

8. Lower the vehicle.