GMC 2012 Canyon Owner's Manual page 275

See
It is not necessary to regularly
check the front axle fluid unless
there is a leak suspected or an
unusual noise is heard. A fluid loss
could indicate a problem. Have it
inspected and repaired.
.
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
front axle, some lubricant may need
to be added.
When the differential is cold, add
enough lubricant to raise the level
to 12 mm (1/2 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.
See
.