wheel GMC ENVOY XL 2004 Workshop Manual

Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in at or rolling terrain.If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that can make
your trips safer and more enjoyable. SeeOff-Road
Driving with Your Four-Wheel-Drive Vehicle on page 4-16
for information about driving off-road.
Keep your vehicle in good shape. Check all uid
levels and also the brakes, tires, cooling system and
transmission. These parts can work hard on
mountain roads.
Know how to go down hills. The most important thing
to know is this: let your engine do some of the
slowing down. Shift to a lower gear when you
go down a steep or long hill.
{CAUTION:
If you do not shift down, your brakes could
get so hot that they would not work well.
You would then have poor braking or even
none going down a hill. You could crash.
Shift down to let your engine assist your
brakes on a steep downhill slope.
4-38

Driving on Snow or Ice
Most of the time, those places where your tires meet
the road probably have good traction.
However, if there is snow or ice between your tires
and the road, you can have a very slippery situation.
You will have a lot less traction or “grip” and will need
to be very careful.What is the worst time for this? “Wet ice.” Very cold
snow or ice can be slick and hard to drive on. But wet
ice can be even more trouble because it may offer
the least traction of all. You can get wet ice when it is
about freezing (32°F; 0°C) and freezing rain begins
to fall. Try to avoid driving on wet ice until salt and sand
crews can get there.
Whatever the condition — smooth ice, packed, blowing
or loose snow — drive with caution.
If you have traction assist, keep the system on. It will
improve your ability to accelerate when driving on a
slippery road. But you can turn the traction system off if
your vehicle ever gets stuck in sand, mud, ice or snow.
SeeIf You Are Stuck: In Sand, Mud, Ice or Snow on
page 4-44. Even though your vehicle has a traction
system, you will want to slow down and adjust your
driving to the road conditions. SeeTraction Assist
System (TAS) on page 4-9.
If you do not have a traction system, accelerate gently.
Try not to break the fragile traction. If you accelerate
too fast, the drive wheels will spin and polish the surface
under the tires even more.
4-41

Then, shut the engine off and close the window almost all
the way to preserve the heat. Start the engine again and
repeat this only when you feel really uncomfortable from
the cold. But do it as little as possible. Preserve the fuel
as long as you can. To help keep warm, you can get out
of the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
If You Are Stuck: In Sand, Mud,
Ice or Snow
In order to free your vehicle when it is stuck, you will
need to spin the wheels, but you do not want to spin your
wheels too fast. The method known as “rocking” can help
you get out when you are stuck, but you must use
caution.
{CAUTION:
If you let your tires spin at high speed, they can
explode, and you or others could be injured.
And, the transmission or other parts of the
vehicle can overheat. That could cause an
engine compartment re or other damage.
When you are stuck, spin the wheels as little
as possible. Do not spin the wheels above
35 mph (55 km/h) as shown on the
speedometer.
Notice:Spinning your wheels can destroy parts of
your vehicle as well as the tires. If you spin the
wheels too fast while shifting your transmission
back and forth, you can destroy your transmission.
For information about using tire chains on your
vehicle, seeTire Chains on page 5-71.
4-44

Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. If you have a
four- wheel-drive vehicle, shift into 4HI. Then shift
back and forth between REVERSE (R) and a forward
gear, spinning the wheels as little as possible. Release
the accelerator pedal while you shift, and press lightly
on the accelerator pedal when the transmission is
in gear. By slowly spinning your wheels in the forward
and reverse directions, you will cause a rocking
motion that may free your vehicle. If that does not get
you out after a few tries, you may need to be towed out.
If you do need to be towed out, seeTowing Your
Vehicle on page 4-45.
Towing
Towing Your Vehicle
Consult your dealer or a professional towing service
if you need to have your disabled vehicle towed.
SeeRoadside Assistance Program on page 7-7.
If you want to tow your vehicle behind another vehicle
for recreational purposes (such as behind a motorhome),
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle – such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as “dinghy towing” (towing your vehicle
with all four wheels on the ground) and “dolly towing”
(towing your vehicle with two wheels on the ground and
two wheels up on a device known as a “dolly”).
With the proper preparation and equipment, many
vehicles can be towed in these ways. See “Dinghy
Towing” and “Dolly Towing,” following. You may
also need brakes for the vehicle being towed. See your
dealer for additional trailering information.
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 4-36.
4-45

Dinghy Towing
When towing your vehicle, turn the ignition off.
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, or dolly
towed. See “Dolly Towing” following for more
information.
4-46

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).
SeeFour-Wheel Drive on page 2-26for the
proper procedure to select the NEUTRAL
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 and leave the steering column
unlocked.
4-47

Dolly Towing
Two-Wheel-Drive Vehicles
Two-wheel-drive vehicles should not be dolly towed.
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 with all four wheels off 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. See
Four-Wheel Drive on page 2-26for the proper
procedure to select the NEUTRAL 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 and lock the steering column.
4-48

Before you start, check all trailer hitch parts and and
attachments, safety chains, electrical connection, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
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.
4-62

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.
{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 won’t move,
even when you’re 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.
See “Four-Wheel Drive (Automatic Transfer
Case)” in the Index.
4-64

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside
of Your Vehicle...........................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-24
Radiator Pressure Cap..................................5-27
Engine Overheating.......................................5-28
Cooling System............................................5-30
Engine Fan Noise.........................................5-36
Power Steering Fluid.....................................5-37Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-43
Rear Axle.......................................................5-48
Four-Wheel Drive............................................5-49
Front Axle......................................................5-50
Bulb Replacement..........................................5-51
Halogen Bulbs..............................................5-51
Headlamps..................................................5-51
Front Turn Signal and Sidemarker Lamps........5-51
Taillamps and Turn Signal Lamps...................5-52
Replacement Bulbs.......................................5-53
Windshield Wiper Blade Replacement..............5-53
Tires..............................................................5-55
Ination - Tire Pressure.................................5-64
Tire Inspection and Rotation...........................5-65
When It Is Time for New Tires.......................5-66
Buying New Tires.........................................5-67
Uniform Tire Quality Grading..........................5-68
Wheel Alignment and Tire Balance..................5-69
Wheel Replacement......................................5-69
Tire Chains..................................................5-71
Section 5 Service and Appearance Care
5-1