Four-Wheel Drive - GMC Sierra 2010 Owner's Manual

For all 6.0L and 6.2L 2500HD Series applications,
the proper level is from 0 to 0.5 inches (0 mm to
13 mm) below the bottom of the filler plug hole,
located on the rear axle. Add only enough fluid to
reach the proper level.
For all 6.6L DURAMAX DIESEL 2500HD Series
applications and all 3500 Series applications, the
proper level is from 0.6 inches to 0.8 inches
(17 mm to 21 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
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See Recommended Fluids and
Lubricants on page 7 12.

Four-Wheel Drive

Lubricant checks in this section also apply to these
vehicles.
Transfer Case
When to Check Lubricant
It is not necessary to regularly check transfer case 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.
6-50
How to Check Lubricant
Electric Shift Transfer Case
A. Fill Plug
B. Drain Plug