
Front Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See Part A:Part A:
Scheduled Maintenance Services on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.If the level is below the bottom of thefiller plug hole,
you may need to add some lubricant.
When the differential is cold, add enough lubricant to
raise the level to 0 to 3/8 inch (9.5 mm) below thefiller
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of thefiller plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See Part D:Part D:
Recommended Fluids and Lubricants on page 6-15.
5-47
2003 - Sierra Denali

A:Front Location
B:Rear Location
Notice:If your vehicle is equipped with
QUADRASTEER™avoid contact with tie rods and
tie rod boots when jacking the vehicle.
{CAUTION:
Getting under a vehicle when it is jacked up is
dangerous. If the vehicle slips off the jack you
could be badly injured or killed. Never get under
a vehicle when it is supported only by a jack.
{CAUTION:
Raising your vehicle with the jack improperly
positioned can damage the vehicle and even
make the vehicle fall. To help avoid personal
injury and vehicle damage, be sure tofit the
jack lift head into the proper location before
raising the vehicle.
3. Position the jack under the vehicle. If theflat tire is
on the front of the vehicle, position the jack on the
frame behind theflat tire.
If theflat tire is on the rear, position the jack under
the rear axle between the spring anchor and the
shock absorber bracket. Jack Positions (overall view)
5-70
2003 - Sierra Denali

Maintenance Schedule......................................6-2
Introduction...................................................6-2
Your Vehicle and the Environment....................6-2
Maintenance Requirements..............................6-2
How This Section is Organized.........................6-3
Part A: Scheduled Maintenance Services...........6-4
Using Your Maintenance Schedule....................6-4
Scheduled Maintenance...................................6-5
Part B: Owner Checks and Services................6-10
At Each Fuel Fill..........................................6-10
At Least Once a Month.................................6-10
At Least Twice a Year...................................6-10At Least Once a Year
...................................6-11
Part C: Periodic Maintenance Inspections
.........6-14
Steering and Suspension Inspection
................6-14
Exhaust System Inspection
............................6-14
Fuel System Inspection
..................................6-14
Engine Cooling System Inspection
...................6-14
Transfer Case and Front Axle (All-Wheel
Drive) Inspection
.......................................6-15
Brake System Inspection
................................6-15
Part D: Recommended Fluids and Lubricants
. . . .6-15
Part E: Maintenance Record
...........................6-17
Section 6 Maintenance Schedule
6-1
2003 - Sierra Denali

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. SeeEngine Oil on
page 5-13for information on resetting the system.
An Emission Control Service.
Lubricate chassis components with each engine oil
and filter change.
Lubricate the front suspension, ball joints, steering
linkage, transmission shift linkage, transfer case shift
linkage and parking brake cable guides. Ball joints
should not be lubricated unless their temperature is 10°F
(-12°C) or higher or they could be damaged.
See the mileage intervals following for additional
services that may be performed with an engine oil
change and chassis lubrication. 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)
❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-58for proper rotation pattern and additional
information.(See footnote +.)
15,000 Miles (25 000 km)
❑Inspect engine air cleanerfilter change indicator.
If necessary, replace thefilter. If vehicle is driven
in dusty/dirty conditions, inspectfilter change
indicator at every engine oil change. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service. (See footnote†.)
❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-58for proper rotation pattern and additional
information.(See footnote +.)
22,500 Miles (37 500 km)
❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-58for proper rotation pattern and additional
information.(See footnote +.)
30,000 Miles (50 000 km)
❑Inspect engine air cleanerfilter change indicator.
If necessary, replace thefilter. If vehicle is driven
in dusty/dirty conditions, inspectfilter change
indicator at every engine oil change. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service. (See footnote†.)
6-6
2003 - Sierra Denali

❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-58for proper rotation pattern and additional
information.(See footnote +.)
❑Replace fuelfilter.An Emission Control Service.
(See footnote†.)
37,500 Miles (62 500 km)
❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-58for proper rotation pattern and additional
information.(See footnote +.)
45,000 Miles (75 000 km)
❑Inspect engine air cleanerfilter change indicator.
If necessary, replace thefilter. If vehicle is driven
in dusty/dirty conditions, inspectfilter change
indicator at every engine oil change. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service. (See footnote†.)
❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.❑Rotate tires. SeeTire Inspection and Rotation on
page 5-58for proper rotation pattern and additional
information.(See footnote +.)
50,000 Miles (83 000 km)
❑Change automatic transmissionfluid andfilter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the fluid and filter at 100,000 miles
(166 000 km).
52,500 Miles (87 500 km)
❑Check rear/front axle uid level and add uid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-58for proper rotation pattern and additional
information.(See footnote +.)
6-7
2003 - Sierra Denali