2003 GMC YUKON DENALI maintenance schedule

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles
(83
000 km) if the vehicle’s GVWR is over 8,600 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.
0 In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If your vehicle’s GVWR is not over 8,600 and you do
not use your vehicle under any of these conditions,
change the fluid and filter every
100,000 miles
(1 66 000 km).
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice: Too much or too little fluid can damage
your transmission. Too much can mean that some of the fluid could come out and fall
on hot engine
part or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid level
if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic - especially in hot weather.
While pulling a trailer.
See
Part A: Scheduled Maintenance Services on
page 6-4.
5-20

See Engine Compartment Overview on page 5-12 for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
3. Check both sides of the dipstick, and read the lower
level. The fluid level must be in the COLD area,
below the cross-hatched area, for a cold check or in
the HOT area or cross-hatched area for a
hot check.
4. If the fluid level is in the acceptable range, push the
dipstick back in all the way; then flip the handle
down
to lock the dipstick in place.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid
to use. See Part D:
Recommended Fluids and Lubricants on page 6-15.
Add fluid only after checking the transmission fluid while
it is hot. (A cold check is used only as
a reference.) If
the fluid level is low, add only enough of the proper fluid
to bring the level up to the HOT area for a hot check.
It doesn't take much fluid, generally less than one
pint (0.5 L). Don't overfill.
Notice: We recommend you use only fluid labeled
DEXRON@
-111, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than DEXRON@
-111 is
not covered by your new vehicle warranty.
After adding fluid, recheck the fluid level as
described under How to Check.
When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down
to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is filled with
DEX-COOL@ engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add
only DEX-COOL@ extended life coolant.
5-22

Brakes
Brake Fluid
Your brake master cylinder reservoir is filled with DOT-3
brake fluid. See Engine Compartment Overview on
page
5-12 for the location of the reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down. The first is that the
brake fluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the fluid level goes back up. The other reason is
that fluid is leaking out of the brake system. If it is, you
should have your brake system fixed, since a leak
means that sooner or later your brakes won’t work well,
or won’t work at all.
So, it isn’t a good idea to “top off’ your brake fluid.
Adding brake fluid won’t correct a leak. If you add fluid
when your linings are worn, then you’ll have
too
much fluid when you get new brake linings. You should
add (or remove) brake fluid, as necessary, only when
work is done on the brake hydraulic system.
If you have too n._.:h brake ------) it can s,
the engine. The fluid will burn if the enginc
... I on
e is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done
on the brake
hydraulic system. See “Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brake fluid. See Part C: Periodic
Maintenance Inspections on page
6- 14.
5-36

All-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. See Part C: Periodic
Maintenance Inspections on page
6-14.
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 the filler plug hole,
you’ll need
to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
Use care not
to overtighten the plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant
to use. See Part D: Recommended
Fluids and Lubricants on page
6-15.
5-46

Front Axle To get an accurate reading, the vehicle should be on a
When to Check and Change Lubricant level surface.
If the level
is below the bottom of the filler plug hole,
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See you may need to add
some lubricant.
Part
A: Scheduled Maintenance Services on page 6-4. When the differential is cold, add enough lubricant to
raise the level to 1/2 inch (12 mm) below the filler
How to Check Lubricant plug hole.
When the differential is at operating temperature
(warm), add enough lubricant
to raise the level to the
bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant
to use. See Part D: Recommended
Fluids and Lubricants on page
6-15.
5-47

Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See 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.
The proper level is from
5/8 inch to 1 5/8 inch (15 mm to
40 mm) below the bottom of the filler plug hole. Add
only enough fluid to reach the proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind
of lubricant to use. See Part D: Recommended
Fluids and Lubricants
on page 6-15.
5-48

Notice: Don’t let anyone tell you that underinflation
or overinflation is all right. It’s not. If your tires
don’t have enough air (underinflation), you can get
the following:
Too much flexing
Too much heat
0 Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overinflation), you
can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell
if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they’re underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Inspection and Rotation
Tires should be rotated every 7,500 miles (12,500 km).
Any time you notice unusual wear, rotate your tires
as soon as possible and check wheel alignment.
Also
check for damaged tires or wheels. See When It Is Time
for New Tires on page
5-58 and Wheel Replacement
on page
5-61 for more information.
Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If
it moves,
use the wheel wrench and jack handle extensions
to
tighten the cable. See Changing a Flat Tire on
page 5-63.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle.
The first rotation
is the most important. See “Part
A: Scheduled
Maintenance Services,” in Section
6, for scheduled
rotation intervals.
5-56

Section 6 Maintenance Schedule
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 Sewices ................ 6-10
At Each Fuel Fill
.......................................... 6-10
At Least Once a Month
................................. 6-10
At Least Twice a Year
................................... 6-10
~~
At 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
Drive) Inspection
....................................... 6.14
Brake System Inspection
................................ 6.14
Part D: Recommended Fluids and Lubricants
.... 6.15
Part E: Maintenance Record
........................... 6.17
Transfer Case and Front
Axle (All-Wheel
6- 1