2007 Hummer H2 Owners Manual PDF | Page 438

How to Check Lubricant
To get an accurate reading, the vehicle should be
on a level surface.
When the differential is cold, the proper level is
from 5/8 inch to 1-5/8 inch (15 mm to 40 mm)
below the bottom of the ?ller plug hole, located on
the rear axle. Add only enough ?uid 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 528.
Four-Wheel Drive
Transfer Case
It is not necessary to regularly check transfer case
?uid unless you suspect there is a leak or you
hear an unusual noise. A ?uid 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 517.