Four-Wheel Drive - GMC 2007 Yukon XL Owner's Manual

Four-Wheel Drive

Lubricant checks in this section also apply to these
vehicles. There are two additional systems that
need lubrication.
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.
How to Check Lubricant
Automatic Transfer Case
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, you'll need to add some lubricant. Add
enough lubricant to raise the level to the bottom of
the filler plug hole. Use care not to overtighten
the plug.
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