The manufacturer recommends that only SAE 80 or 80W-90 GL-5 Gear Lubricants be used in conventional differentials. For cars equipped with Positraction (limited-slip differential), special Positraction lubricant must be used.
Remove the lubricant filler plug from the differential housing from underneath the car to check the rear axle lubricant level. If necessary, add the proper lubricant to bring the level to the filler plug hole. Replace the filler plug.
DRAIN & REFILL
The rear axle lubricant does not normally require changing for the life of the vehicle. However, if the vehicle is used to pull a trailer, change the rear axle lubricant every 12,000 miles (15,000 miles on 1978 and 1979 models).
If additions are necessary or when refilling the axle after service, proceed as follows:
- Jack and safely support the rear of the vehicle.
- If equipped, remove the drain plug and drain off the old lubricant. Remove the fill plug to act as a vent. If only a fill plug is provided, the lubricant will have to be removed with a suction gun, or the cover will have to be removed. If the cover is removed, be sure to use a new gasket on installation.
- Fill the axle to the bottom of the fill plug hole with SAE 80 or SAE 90 GL-5 gear lubricant (use SAE 80 GL-5 gear lubricant in Canadian vehicles).
- Reinstall the fill plug and check for leaks.
- Lower the vehicle.