GMC 2011 Sierra - Manual (Page 460)

Black plate (36,1) GMC Sierra Owner Manual - 2011
10-36 Vehicle Care
Front Axle
When to Check and Change
Lubricant
It is not necessary to regularly
check front axle fluid unless a leak
is suspected, or an unusual noise is
heard. 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. 1500 Series
A. Fill Plug
B. Drain Plug
All Except 1500 Series
A. Fill Plug
B. Drain Plug
. When the differential is cold,
add enough lubricant to raise the
level from 0 mm (0 in) to 3.2 mm
(1/8 in) below the fill plug hole.
. When the differential is at
operating temperature (warm),
add enough lubricant to raise
the level to the bottom of the fill
plug hole.