GM Chevrolet Avalanche - Manual (Page 384)

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 2500 Series
is from 0 to 1/2 inch (0 to 13 mm) below the bottom
of the filler plug hole. 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 6-13.
Four-Wheel Drive
Transfer Case
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.
Refer to the Maintenance Schedule to determine how
often to change the lubricant. See Scheduled
Maintenance on page 6-4.
1500 Series shown, 2500 Series similar
5-50