GMC 1996 Sierra Owner's Manual page 276

Front Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often
t o
check the lubricant and when to change it. See
"Scheduled Maintenance Services" in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole.
you'll need to add some lubricant.
If the differential is at operating temperature (warm),
add enough lubricant t o raise the level to the bottom of
the filler plug hole.
If the differential is cold, add enough lubricant to raise
the level to 1/2 inch ( 1 2 mm) below the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See "Recommended Fluids and
Lubricants" in the Index.
Engine Coolant
The cooling system in your vehicle is filled with new
DEX-COOL
TM
(orange-colored, silicate-free) engine
coolant. This coolant is designed
to
remain in your
vehicle for 5 years or 100,000 miles
( 1
66 000 km),
whichever occurs first.
The following explains your cooling system and how
to add coolant when
it
is low. I f you have a problem
with engine overheating, see "Engine Overheating" in
the Index.
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