2003 GMC ENVOY Rear axle

Indicator Light
The indicator light on the in¯ator switch in the rear
passenger compartment also serves as an indicator for
internal system error. If the indicator light is ¯ashing
without the load leveling function or the in¯ator being
active, turn off the ignition. The next day turn on
the ignition and check the indicator light. The vehicle
can be driven with the light ¯ashing, but if it is you
should have the vehicle serviced as soon as possible.
Adding a Snow Plow or Similar
Equipment
Your vehicle was neither designed nor intended for a
snow plow.
Notice:Adding a snow plow or similar equipment
to your vehicle can damage it, and the repairs
wouldn't be covered by warranty. Do not install a
snow plow or similar equipment on your vehicle.
Towing a Trailer
{CAUTION:
If you don't use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well -- or even
at all. You and your passengers could be
seriously injured. Pull a trailer only if you have
followed all the steps in this section. Ask your
dealer for advice and information about towing
a trailer with your vehicle.
Notice:Pulling a trailer improperly can damage
your vehicle and result in costly repairs not covered
by your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer with
your vehicle. Additional rear axle maintenance
is required for a vehicle used to tow a trailer. See
ªScheduled Maintenance Servicesº in the Index.
To identify the trailering capacity of your vehicle,
you should read the information in ªWeight of the Trailerº
that appears later in this section.
4-50

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-24
Radiator Pressure Cap..................................5-26
Engine Overheating.......................................5-27
Cooling System............................................5-29
Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle.......................................................5-48
Four-Wheel Drive............................................5-48
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Headlamps..................................................5-50
Front Turn Signal and Sidemarker Lamps........5-51
Taillamps and Turn Signal Lamps...................5-51
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-54
In¯ation -- Tire Pressure................................5-55
Tire Inspection and Rotation...........................5-55
When It Is Time for New Tires.......................5-57
Buying New Tires.........................................5-58
Uniform Tire Quality Grading..........................5-59
Wheel Alignment and Tire Balance..................5-60
Wheel Replacement......................................5-60
Tire Chains..................................................5-62
Accessory In¯ator.........................................5-62
If a Tire Goes Flat........................................5-64
Changing a Flat Tire.....................................5-64
Section 5 Service and Appearance Care
5-1

Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
The proper level is from 0 to 3/8 inch (0 to 10 mm)
below the bottom of the ®ller plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeePart D: Recommended
Fluids and Lubricants on page 6-18.
Four-Wheel Drive
Lubricant checks in this section also apply to these
vehicles. However, there are two additional systems that
need lubrication.
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeePart C: Periodic
MaintenanceInspections on page 6-16.
5-48

If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed. See
Engine Oil on
page 5-15for information on resetting the system.
An Emission Control Service.
See the mileage intervals following for additional
services that may be performed with an engine oil
change. After the services are performed, record the
date, odometer reading and who performed the service
on the maintenance record pages in Part E of this
schedule.
7,500 Miles (12 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
15,000 Miles (25 000 km)
qInspect engine air cleaner ®lter or change indicator (if
equipped). If necessary, replace the ®lter. If vehicle is
driven in dusty/dirty conditions, inspect ®lter or
change indicator (if equipped) at every engine oil
change. See
Engine Air Cleaner/Filter on page 5-20for more information.An Emission Control Service.
(See footnote ².)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
22,500 Miles (37 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
6-6

30,000 Miles (50 000 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
qReplace fuel ®lter.An Emission Control Service. (See
footnote ².)
qReplace engine air cleaner ®lter on vehicles without
a restriction indicator. If equipped with a change
indicator, inspect the indicator. If necessary, replace
the ®lter. If vehicle is driven in dusty/dirty conditions,
inspect the change indicator (if equipped) at every
engine oil change. See
Engine Air Cleaner/Filter on
page 5-20for more information.An Emission
Control Service. (See footnote ².)
37,500 Miles (62 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
45,000 Miles (75 000 km)
qInspect engine air cleaner ®lter or change indicator (if
equipped). If necessary, replace the ®lter. If vehicle is
driven in dusty/dirty conditions, inspect ®lter or
change indicator (if equipped) at every engine oil
change. See
Engine Air Cleaner/Filter on page 5-20for more information.An Emission Control Service.
(See footnote ².)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
6-7

50,000 Miles (83 000 km)
qChange automatic transmission ¯uid and ®lter if the
vehicle is mainly driven under one or more of these
conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC) or
higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the ¯uid and ®lter at 100,000 miles
(166 000 km).
qAutomatic Transfer Case Only: Change transfer case
¯uid.
52,500 Miles (87 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
60,000 Miles (100 000 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
qReplace fuel ®lter.An Emission Control Service. (See
footnote ².)
qReplace engine air cleaner ®lter on vehicles without
a restriction indicator. If equipped with a change
indicator, inspect the indicator. If necessary, replace
the ®lter. If vehicle is driven in dusty/dirty conditions,
inspect the change indicator (if equipped) at every
engine oil change. See
Engine Air Cleaner/Filter on
page 5-20for more information.An Emission
Control Service. (See footnote ².)
67,500 Miles (112 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
6-8

75,000 Miles (125 000 km)
qInspect engine air cleaner ®lter or change indicator (if
equipped). If necessary, replace the ®lter. If vehicle is
driven in dusty/dirty conditions, inspect ®lter or
change indicator (if equipped) at every engine oil
change. See
Engine Air Cleaner/Filter on page 5-20for more information.An Emission Control Service.
(See footnote ².)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
82,500 Miles (137 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
90,000 Miles (150 000 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qReplace fuel ®lter.
An Emission Control Service. (See
Footnote ².)
qReplace engine air cleaner ®lter on vehicles without
a restriction indicator. If equipped with a change
indicator, inspect the indicator. If necessary, replace
the ®lter. If vehicle is driven in dusty/dirty conditions,
inspect the change indicator (if equipped) at every
engine oil change. See
Engine Air Cleaner/Filter on
page 5-20for more information.An Emission
Control Service. (See footnote ².)
qRotate tires. SeeTire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
97,500 Miles (162 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-55for proper rotation pattern and additional
information.(See footnote +.)
6-9

Part C: Periodic
MaintenanceInspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall).
You should let your dealer's
service department do these jobs. Make sure any
necessary repairs are completed at once.
Proper procedures to perform these services may be
found in a service manual. SeeService Publications
Ordering Information on page 7-10.
Steering, Suspension and Front
Drive Axle Boot and Seal Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook-up, binding, leaks,
cracks, cha®ng, etc. Clean and then inspect the drive
axle boot seals for damage, tears or leakage. Replace
seals if necessary.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out-of-position parts as well as open seams,
holes, loose connections or other conditions which
could cause a heat build-up in the ¯oor pan or could let
exhaust fumes into the vehicle. See
Engine Exhaust
on page 2-33.
Fuel System Inspection
Inspect the complete fuel system for damage or leaks.
6-16