Four-Wheel Drive - Chevrolet 2008 Silverado 1500 Pickup Owner's Manual

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.
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How to Check Lubricant
Electric Shift Transfer Case
A. Fill Plug
B. Drain Plug