2001 GMC YUKON XL DENALI automatic transmission fluid

4-52 Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't
overfill), engine oil, axle lubricant, belt, cooling system
and brake system. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you're trailering, it's a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven
-pin universal
heavy
-duty trailer connector is attached to a bracket on
the platform hitch.

6-
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel
6
-5 Fuels in Foreign Countries
6
-5 Filling Your Tank
6
-7 Filling a Portable Fuel Container
6
-8 Checking Things Under the Hood
6
-10 Engine Oil
6
-15 Engine Air Cleaner/Filter
6
-17 Passenger Compartment Air Filter
6
-17 Automatic Transmission Fluid
6
-21 Rear Axle
6
-21 All-Wheel Drive
6
-24 Engine Coolant
6
-27 Coolant Surge Tank Pressure Cap
6
-28 Power Steering Fluid6
-29 Windshield Washer Fluid
6
-30 Brakes
6
-34 Battery
6
-35 Bulb Replacement
6
-39 Windshield Wiper Blade Replacement
6
-40 Tires
6
-48 Appearance Care
6
-49 Cleaning the Inside of Your Vehicle
6
-52 Cleaning the Outside of Your Vehicle
6
-56 GM Vehicle Care/Appearance Materials
6
-57 Vehicle Identification Number (VIN)
6
-58 Electrical System
6
-66 Replacement Bulbs
6
-66 Capacities and Specifications
6
-67 Normal Maintenance Replacement Parts

6-9 Engine Compartment Overview
When you lift the hood on the VORTEC 6000 engine, you'll see:
A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Dipstick
E. Engine Oil Fill
F. Automatic Transmission DipstickG. Fan
H. Remote Negative (
-)
Terminal (GND)
I. Remote Positive (+) Terminal
J. Power Steering Fluid ReservoirK. Brake Fluid Reservoir
L. Underhood Electrical Center
M. Battery
N. Windshield Washer
Fluid Reservoir

6-17
Passenger Compartment Air Filter
The filter is located under the instrument panel below
the glove compartment.
To replace the passenger compartment air filter do
the following:
1. Remove the bolts on the access panel and set the
panel aside. Because this operation can be a little
difficult, you may choose to have it done at your
dealer's service department.
2. Reach under the
instrument panel
towards the front of
the vehicle and pull
down on the filter
retaining bracket.
3. Remove the air filter by pulling down on the
element. Remove the second portion of the air filter
by sliding it towards the rear of the vehicle and then
pulling downward.4. Install the new filter by reversing the steps listed
previously. Be sure to follow any instructions that
may be included in the replacement filter package.
Refer to the Maintenance Schedule to determine when
to replace the passenger compartment air filter. See
ªScheduled Maintenanceº in the Index.
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 is mainly driven under one
or more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) 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
every 100,000 miles (166 000 km).
See ªScheduled Maintenance Servicesº in the Index.

6-20
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 ªRecommended
Fluids and Lubricantsº in the Index.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-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than
DEXRON
-III is not covered by your new
vehicle warranty.

After adding fluid, recheck the fluid level as
described under ªHow to Check.º

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.

Scheduled Maintenance
7-11
50,000 Miles (83 000 km)

Change automatic transmission fluid and filter 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 fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking.
Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE

Scheduled Maintenance
7-15

Change automatic transmission fluid and filter 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 transmission fluid,
change both the fluid and filter.
Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
Drain, flush and refill cooling system (or every 60 months since last service,
whichever occurs first). See ªEngine Coolantº in the Index for what to use.
Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test
the cooling system and pressure cap.
An Emission Control Service.ACTUAL
SERVICED BY:MILEAGE
DATE

7-18
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them
last longer, seal better, and not stick or squeak.
Apply silicone grease with a clean cloth. During very
cold, damp weather more frequent application may be
required. See ªRecommended Fluids and Lubricantsº
in the Index.
Automatic Transmission Check
Check the transmission fluid level; add if needed.
See ªAutomatic Transmission Fluidº in the Index.
A fluid loss may indicate a problem. Check the system
and repair if needed.At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part D.
Body Lubrication Service
Lubricate all hood latch assembly, secondary latch,
pivots, spring anchor, release pawl, rear compartment
hinges, liftgate handle pivot points, latch bolt, fuel door
hinge, and folding seat hardware. Part D tells you what
to use. More frequent lubrication may be required when
exposed to a corrosive environment.