GMC 2004 Sierra 1500 Pickup, Owner'S Manual, Page: 459 / 588

Rear Axle
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 for the 1500 Series is from 5/8 inch to
1 5/8 inch (15 mm to 40 mm) below the bottom of the filler
plug hole. The proper level for the 1500 HD Series,
2500 Series, 2500 HD, and 3500 Series is from 0 to
1/2 inch (0 to 13 mm) below the bottom of the filler plug
hole. The proper level for the 1500 and 2500 Series
vehicles with QUADRASTEER™ (4 Wheel Steer) is from
0 to 1/4 inch (0 to 6 mm) below the filler plug hole. 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 on page 6-14.
1500 Series Shown, 2500 Series Similar
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