When to Check Lubricant
It is not necessary to regularly check rear axle fluid unless you suspect there is a leak or you hear an unusual noise. A fluid loss could indicate a problem. Have it inspected and repaired.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a level surface.
The proper level is from 0 to 0.4 inch (0 to 10 mm) below the bottom of the filler plug hole, located on the rear axle.
Add only enough fluid to reach the proper level.
What to Use
To determine what kind of lubricant to use, see Recommended Fluids and Lubricants .
To add lubricant when the level is low, use SAE 75W-90 Synthetic Axle Lubricant (GM Part No. U.S. 12378261, in Canada 10953455) meeting GM Specification 9986115. To completely refill after draining, add 4 ounces (118 ml) of Limited-Slip Axle Lubricant Additive (GM Part No. U.S. 1052358, in Canada 992694). Then fill to the bottom of the filler plug hole with the Synthetic Gear Lubricant.
