It is not necessary to regularly check the rear axle fluid unless there is a leak in the system or you hear an unusual noise. A fluid loss in the system indicates that you have a problem. Have the system inspected and repaired.

To get an accurate reading, the vehicle should be on a level surface.

The proper level is from 0 to 3/8 inch (0 to 10 mm) below the bottom of the filler plug hole.

If the level is below the bottom of the filler plug hole, located on the rear axle, you'll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole.

See Recommended Fluids and Lubricants for the type of fluid to use.