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.

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

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

See Recommended Fluids and Lubricants to determine which kind of lubricant to use.