wheel GMC ENVOY DENALI 2006 Repair Manual

Here are some important things to consider before you
do recreational vehicle towing:
What’s the trailering capacity of the towing vehicle?
Be sure you read the tow vehicle manufacturer’s
recommendations.
How far will you tow? Some vehicles have
restrictions on how far and how long they can
be towed.
Do you have the proper towing equipment? See
your dealer or trailering professional for additional
advice and equipment recommendations.
Is your vehicle ready to be towed? Just as you
would prepare your vehicle for a long trip, you’ll
want to make sure your vehicle is prepared to be
towed. SeeBefore Leaving on a Long Trip on
page 4-37.
Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If you tow your vehicle with all four wheels
on the ground, the drivetrain components could
be damaged. The repairs would not be covered by
your warranty. Do not tow your vehicle with all
four wheels on the ground.
Two-wheel-drive vehicles should not be towed with all
four wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed. To properly tow these vehicles,
they should be placed on a platform trailer.
4-51

Four-Wheel-Drive Vehicles
Four-wheel-drive vehicles can be dinghy towed if you
follow the proper procedures. The transmission has no
provisions for internal lubrication while being towed, so it
is important that you follow all the steps listed in this
manual to dinghy tow your four-wheel-drive vehicle.
Use the following procedure to tow your vehicle:
1. Shift the transmission to PARK (P).
2. Turn the engine off, but leave the ignition on.
3. Firmly set the parking brake.
4. Securely attach the vehicle being towed to the
tow vehicle.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
5. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-27for the proper
procedure to select the NEUTRAL (N) position for
your vehicle.
6. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
7. Turn the ignition off.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-27.
4-52

Dolly Towing
Front Towing
(Front Wheels Off the Ground)
Two-Wheel-Drive Vehicles
Notice:If you tow a two-wheel-drive vehicle with
the rear wheels on the ground, the transmission
could be damaged. The repairs would not be
covered by your warranty. Never tow your vehicle
with the rear wheels on the ground.
Four-Wheel-Drive Vehicles
Four-wheel-drive vehicles can be dolly towed with the
rear wheels on the ground.
Use the following procedure to tow your vehicle:
1. Drive the vehicle onto the tow dolly.
2. Shift the automatic transmission to PARK (P).
3. Turn the engine off, but leave the ignition on.
4. Firmly set the parking brake.
5. Securely attach the vehicle being towed to
the dolly.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
6. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-27for the proper
procedure to select the NEUTRAL (N) position for
your vehicle.
7. Release the parking brake only after the
vehicle being towed is rmly attached to the
towing vehicle.
8. Turn the ignition off.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-27.
4-53

Rear Towing
(Rear Wheels Off the Ground)
(Two-Wheel or Four-Wheel-Drive Vehicles)
Use the following procedure to tow your vehicle from
the rear:
1. Drive the vehicle onto the dolly.
2. Firmly set the parking brake. SeeParking Brake on
page 2-31for more information.
3. Shift the transmission in PARK (P).4. Follow the dolly manufacturer’s instructions to
attach and secure the vehicle being towed to
the dolly and then the loaded dolly to the tow
vehicle. Use an adequate clamping device to
ensure that the front wheels are locked into the
straight position.
5. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
6. Turn the ignition to LOCK.
If the tow vehicle will not be started or driven for
six weeks or more, remove the battery cable
from the negative terminal (post) of the battery.
4-54

Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good deal
longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns than
normal. Do this so your trailer won’t strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
4-65

Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or a lower gear, under heavy
loads or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs similar
to engine overheating. To avoid this, let the engine run
while parked (preferably on level ground) with the
automatic transmission in PARK (P) for a few minutes
before turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 5-28.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
2. Have someone place chocks under the
trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P).
5. Release the regular brakes.
4-66

{CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake rmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle will not move,
even when you are on fairly level ground, use
the steps that follow.
Always put the shift lever fully in PARK (P) with
the parking brake rmly set.
If the transfer case on four-wheel drive vehicles
is in NEUTRAL, your vehicle will be free to roll,
even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear — not
in NEUTRAL.
SeeFour-Wheel Drive on page 2-27.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store
the chocks.
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 uid (don’t overll),
engine oil, axle lubricant, belt(s), cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd 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.
4-67

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Oil Life System..................................5-20
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-23
Engine Coolant.............................................5-25
Radiator Pressure Cap..................................5-28
Engine Overheating.......................................5-28
Cooling System............................................5-30
Engine Fan Noise.........................................5-35Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle.......................................................5-47
Four-Wheel Drive............................................5-48
Front Axle......................................................5-49
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Headlamps, Front Turn Signal, Sidemarker,
and Parking Lamps....................................5-50
Taillamps, Turn Signal, and Stoplamps............5-51
Back-Up Lamps............................................5-52
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-53
Tires..............................................................5-55
Tire Sidewall Labeling...................................5-56
Tire Terminology and Denitions.....................5-59
Ination - Tire Pressure.................................5-62
Tire Inspection and Rotation...........................5-63
When It Is Time for New Tires.......................5-65
Buying New Tires.........................................5-66
Different Size Tires and Wheels......................5-67
Uniform Tire Quality Grading..........................5-68
Section 5 Service and Appearance Care
5-1

Wheel Alignment and Tire Balance..................5-69
Wheel Replacement......................................5-69
Tire Chains..................................................5-71
Accessory Inator.........................................5-71
If a Tire Goes Flat........................................5-73
Changing a Flat Tire.....................................5-74
Removing the Spare Tire and Tools................5-75
Removing the Flat Tire and Installing
the Spare Tire..........................................5-78
Secondary Latch System...............................5-84
Storing a Flat or Spare Tire and Tools............5-88
Spare Tire...................................................5-92
Appearance Care............................................5-92
Cleaning the Inside of Your Vehicle.................5-92
Fabric/Carpet...............................................5-94
Leather.......................................................5-94
Instrument Panel, Vinyl, and Other
Plastic Surfaces........................................5-95
Care of Safety Belts......................................5-95
Weatherstrips...............................................5-95
Washing Your Vehicle...................................5-96
Cleaning Exterior Lamps/Lenses.....................5-96Finish Care..................................................5-96
Windshield, Backglass, and Wiper Blades.........5-97
Aluminum Wheels.........................................5-98
Tires...........................................................5-98
Sheet Metal Damage.....................................5-99
Finish Damage.............................................5-99
Underbody Maintenance................................5-99
Chemical Paint Spotting.................................5-99
Vehicle Care/Appearance Materials................5-100
Vehicle Identication.....................................5-101
Vehicle Identication Number (VIN)................5-101
Service Parts Identication Label...................5-101
Electrical System..........................................5-102
Add-On Electrical Equipment.........................5-102
Headlamps.................................................5-102
Windshield Wiper Fuses...............................5-102
Power Windows and Other Power Options......5-102
Fuses and Circuit Breakers..........................5-103
Engine Compartment Fuse Block...................5-103
Rear Underseat Fuse Block..........................5-111
Capacities and Specications........................5-119
Section 5 Service and Appearance Care
5-2

Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving, except when you are pushing on the
brake pedal rmly.
{CAUTION:
The brake wear warning sound means that soon
your brakes will not work well. That could lead
to an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.Some driving conditions or climates may cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque specications.
Brake linings should always be replaced as complete
axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in
pedal travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
5-40