2004 CHEVROLET AVALANCHE transmission

{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. SeeParking Brake on
page 2-42.
6. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-38for 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.
Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the vehicle
capacity weight and includes the weight of all occupants,
cargo and all nonfactory-installed options. Two labels
on your vehicle show how much weight it may properly
carry, the Tire and Loading Information label and the
Certication/Tire label.
{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
4-55

If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you’ll be driving. A good source for
this information can be state or provincial police.
Consider using a sway control. See “Hitches” later
in this section.
Don’t tow a trailer at all during the rst 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that you
tow a trailer, don’t drive over 50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or, if necessary, a
lower gear selection if the transmission shifts
too often (e.g., under heavy loads and/or hilly
conditions). See “Tow/Haul Mode” later in
this section.
Three important considerations have to do with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
4-69

Tow/Haul Mode
Tow/haul is designed to assist while your vehicle is
pulling a large or heavy load or trailer. Tow/haul is most
useful while pulling such a load in rolling terrain, in
stop-and-go traffic, or when you need improved
low-speed control, such as when parking. The purpose
of the tow/haul mode is to do the following:
Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Tow/haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75% of
the vehicle’s Gross Combination Weight Rating
(GCWR). See “Weight of the Trailer” later in this section.Press the button at the end of the shift lever to
enable/disable the tow/haul mode.
4-70

A light on the instrument
panel will illuminate to
indicate that tow/haul
mode has been selected.
The vehicle will automatically turn off tow/haul every
time it is started.
Driving with tow/haul activated without a heavy load or
with no trailer will cause reduced fuel economy and
unpleasant engine and transmission driving
characteristics, but will not cause damage.
Operating the vehicle in tow/haul when lightly loaded or
with no trailer at all will not cause damage. However,
there is no benet to the selection of tow/haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission driving
characteristics and reduced fuel economy. Tow/haul
is recommended only when pulling a heavy trailer or a
large or heavy load.Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull
a trailer are all important. And, it can also depend
on any special equipment that you have on your vehicle.
Use one of the following charts to determine how
much your vehicle can weigh, based upon your vehicle
model and options.
Maximum trailer weight is calculated assuming the
driver and one passenger are in the tow vehicle and it
has all the required trailering equipment. The weight
of additional optional equipment, passengers and cargo
in the tow vehicle must be subtracted from the
maximum trailer weight.
Above the 5,000 lbs. (2 268 kg) trailer rating, the
handling/trailering suspension is required on C-1500
models and the handling/trailering or off-road suspension
is required on K-1500 models.
Notice:Using a fth-wheel or goose-neck hitch
device on your vehicle could damage the vehicle.
The repairs would not be covered by your warranty.
Do not use a fth-wheel or goose-neck hitch
device on your vehicle.
4-71

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.
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, if necessary, a lower gear
selection if the transmission shifts too often (e.g.,
under heavy loads and/or hilly conditions).You may also want to activate the tow/haul mode if the
transmission shifts too often. See “Tow/Haul Mode”
earlier in this section.
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 5-29.
4-77

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, belts, 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.
Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with the eight-wire trailer
towing harness. This harness with a seven-pin universal
heavy-duty trailer connector is attached to a bracket
on the hitch platform.
The Center High-Mounted Stoplamp (CHMSL) wire is tied
next to the trailer wiring harness for use with a trailer.
4-79

Service............................................................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 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.........................5-23
Engine Coolant.............................................5-26
Coolant Surge Tank Pressure Cap..................5-29
Engine Overheating.......................................5-29
Cooling System............................................5-33Engine Fan Noise.........................................5-40
Power Steering Fluid.....................................5-41
Windshield Washer Fluid................................5-42
Brakes........................................................5-43
Battery........................................................5-47
Jump Starting...............................................5-48
Rear Axle.......................................................5-55
Four-Wheel Drive............................................5-56
Front Axle......................................................5-57
Bulb Replacement..........................................5-58
Halogen Bulbs..............................................5-58
Headlamps..................................................5-58
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-62
Front Turn Signal, Sidemarker and
Daytime Running Lamps.............................5-63
Daytime Running Lamps................................5-65
Center High-Mounted Stoplamp (CHMSL).........5-65
Taillamps.....................................................5-65
Replacement Bulbs.......................................5-66
Windshield Wiper Blade Replacement..............5-67
Section 5 Service and Appearance Care
5-1

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
B. Coolant Surge Tank. SeeCooling System on
page 5-33andCoolant Surge Tank Pressure Cap
on page 5-29.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-21.
D. Engine Oil Fill. SeeEngine Oil on page 5-16.
E. Engine Oil Dipstick. SeeEngine Oil on page 5-16.
F. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-23.
G. Fan. SeeCooling System on page 5-33andEngine
Fan Noise on page 5-40.H. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-48.
I. Power Steering Fluid Reservoir (Out of View). See
Power Steering Fluid on page 5-41.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-48.
K. Brake Fluid Reservoir. SeeBrakes on page 5-43.
L. Underhood Fuse Block. See “Underhood Fuse Block”
underFuses and Circuit Breakers on page 5-120.
M. Battery. SeeBattery on page 5-47.
N. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-42.
5-13