Hummer 2006 H3 - Manual (Page 316)

Rear Axle
When to Check and Change 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.
If the level is below the bottom of the filler plug hole,
located on the rear axle, you will need to add some
lubricant. Add enough lubricant to raise the level to
the bottom of the filler plug hole.
What to Use
See Recommended Fluids and Lubricants on page 6-12
to determine which kind of lubricant to use.
Four-Wheel Drive
It is recommended that the four-wheel drive transfer
case fluid be checked and filled by your dealer.
Front Axle
It is recommended that the front axle fluid be checked
and filled by your dealer.
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