2003 GMC YUKON engine

67,500 Miles (112 500 km)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-61for proper rotation pattern and additional
information.(See footnote +.)
75,000 Miles (125 000 km)
❑Inspect engine air cleanerlter or change indicator (if
equipped). If necessary, replace thelter. If vehicle is
driven in dusty/dirty conditions, inspectlter or
change indicator (if equipped) at every engine oil
change. SeeEngine Air Cleaner/Filter on page 5-21
for more information.An Emission Control Service.
(See footnote†.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-61for proper rotation pattern and additional
information.(See footnote +.)
82,500 Miles (137 500 km)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-61for proper rotation pattern and additional
information.(See footnote +.)
90,000 Miles (150 000 km)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Replace fuellter.An Emission Control Service.
(See footnote†.)
❑Replace engine air cleanerlter on vehicles without
a restriction indicator. If equipped with a change
indicator, inspect the indicator. If necessary, replace
thelter. If vehicle is driven in dusty/dirty conditions,
inspect the change indicator (if equipped) at every
engine oil change. SeeEngine Air Cleaner/Filter on
page 5-21for more information.An Emission
Control Service. (See footnote†.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-61for proper rotation pattern and additional
information.(See footnote +.)
6-9
2003 - Yukon/Yukon XL

97,500 Miles (162 500 km)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-61for proper rotation pattern and additional
information.(See footnote +.)
100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission Control
Service.
❑Replace spark plugs.An Emission Control Service.
❑Change automatic transmissionuid andlter if
the vehicle’s GVWR is over 8,600 lbs or 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 haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmissionuid, change
both theuid andlter.
❑Change transfer caseuid.
❑Except 8.1L V8 Engine: Inspect Positive Crankcase
Ventilation (PCV) valve.An Emission Control
Service.
150,000 Miles (240 000 km)
❑Drain,ush and rell cooling system (or every
60 months since last service, whichever occursrst).
SeeEngine Coolant on page 5-26for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.An Emission
Control Service.
6-10
2003 - Yukon/Yukon XL

Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals specied to
help ensure the safety, dependability and emission
control performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever anyuids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
in Part D.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuelfill.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-16for further
details.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-26for further details.
Windshield Washer Fluid Level Check
Check the windshield washeruid level in the windshield
washer tank and add the properuid if necessary.
SeeWindshield Washer Fluid on page 5-39for further
details.
At Least Once a Month
Tire Inflation Check
Make sure tires are inated to the correct pressures.
Don’t forget to check your spare tire. SeeTires on
page 5-60for further details.
Cassette Tape Player Service
Clean cassette tape player. Cleaning should be done
every 50 hours of tape play. SeeAudio System(s)
on page 3-71for further details.
6-11
2003 - Yukon/Yukon XL

Starter Switch Check
{CAUTION:
When you are doing this check, the vehicle
could move suddenly. If it does, you or others
could be injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. SeeParking Brake on page 2-34if
necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The starter
should work only in PARK (P) or NEUTRAL (N).
If the starter works in any other position, your
vehicle needs service.
Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this check, the vehicle
could move suddenly. If it does, you or others
could be injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-34if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the key to the RUN
position, but don’t start the engine. Without applying
the regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), your vehicle needs service.
6-13
2003 - Yukon/Yukon XL

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.
The key should turn to LOCK only when the
shift lever is in PARK (P).
The key should come out only in LOCK.
Parking Brake and Automatic
Transmission Park (P) Mechanism
Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
To check the parking brake’s holding ability: With the
engine running and transmission in NEUTRAL (N),
slowly remove foot pressure from the regular brake
pedal. Do this until the vehicle is held by the parking
brake only.
To check the PARK (P) mechanism’s holding ability:
With the engine running, shift to PARK (P). Then
release the parking brake followed by the regular
brake.
Underbody Flushing Service
At least every spring, use plain water toush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-14
2003 - Yukon/Yukon XL

Part C: Periodic Maintenance
Inspections
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 and Suspension 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, chang, etc.
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 theoor pan or could let
exhaust fumes into the vehicle. SeeEngine Exhaust
on page 2-38.
Fuel System Inspection
Inspect the complete fuel system for damage or leaks.
6-15
2003 - Yukon/Yukon XL

Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
Every 12 months or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. Auid loss could indicate a problem;
check and have it repaired, if needed. On manual
shift transfer case, oil the control lever pivot point. Check
vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
chang, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.
6-16
2003 - Yukon/Yukon XL

Part D: Recommended Fluids and
Lubricants
Fluids and lubricants identied below by name, part
number or specication may be obtained from your
dealer.
Usage Fluid/Lubricant
Engine OilEngine oil with the American
Petroleum Institute Certied for
Gasoline Engines starburst symbol
of the proper viscosity. To determine
the preferred viscosity for your
vehicle’s engine, seeEngine Oil on
page 5-16.
Engine Coolant50/50 mixture of clean, drinkable
water and use only
DEX-COOL
®Coolant. SeeEngine
Coolant on page 5-26.
Hydraulic Brake
SystemDelco Supreme 11 Brake Fluid or
equivalent DOT-3 brakeuid.
Windshield
Washer SolventGM Optikleen
®Washer Solvent or
equivalent.
Power Steering
SystemGM Power Steering Fluid (GM Part
No. U.S. 1052884, in Canada
993294, or equivalent).
Automatic
TransmissionDEXRON
®-III Automatic
Transmission Fluid.
Usage Fluid/Lubricant
Key Lock
CylindersMulit-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474, or equivalent).
Chassis
LubricationChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Front Axle
(Four-Wheel
Drive)SAE 80W-90 Axle Lubricant
(GM Part No. U.S. 1052271, in
Canada 10950849 or equivalent).
Front Axle
(All-Wheel
Drive)SAE 75W-90 Synthetic Axle
Lubricant (GM Part No. U.S.
12378261, in Canada 10953455) or
equivalent meeting GM Specication
9986115.
Rear AxleSAE 75W-90 Synthetic Axle
Lubricant (GM Part No. U.S.
12378261, in Canada 10953455) or
equivalent meeting GM Specication
9986115.
Rear Axle
(Steerable)Synthetic Axle Lubricant; use only
GM Part No. 12378557 (in Canada
88901362). Do not add friction
modier.
Transfer Case
(All-Wheel
Drive with
Stabilitrak
®)Dexron-III Automatic Transmission
Fluid.
6-17
2003 - Yukon/Yukon XL