2008 CHEVROLET SUBURBAN torque

Automatic Transmission Operation
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
If your vehicle is has an automatic transmission,
it has an electronic shift position indicator within the
instrument panel cluster. This display comes on when
the ignition key is turned to the ON/RUN position.
There are several different positions for the shift lever.
See “Range Selection Mode” later in this section.
PARK (P):This position locks your rear wheels. It is
the best position to use when you start the engine
because your vehicle cannot move easily. When parked
on a hill, especially when the vehicle has a heavy
load, you might notice an increase in the effort to shift
out of Park. See Torque Lock (Automatic Transmission)
underShifting Into Park on page 2-43for more
information.
Hydra-Matic
®4-Speed
Automatic Transmission
Allison Transmission®or Hydra-Matic®6-Speed
Automatic Transmission
2-30

To use this feature, do the following:
1. Move the shift lever to the MANUAL MODE (M).
2. Press the plus/minus buttons, located on the
steering column shift lever, to select the desired
range of gears for your current driving conditions.
When MANUAL MODE (M) is selected a number
displays next to the M, indicating the current gear.
This number is the highest gear that can be used.
However, your vehicle can automatically shift to lower
gears as it adjusts to driving conditions. This means that
all gears below that number are available. When
FIFTH (5) is selected, FIRST (1) through FIFTH (5)
gears are automatically shifted by the vehicle, but
SIXTH (6) cannot be used until the plus/minus button
located on the steering column lever is used to change
to the gear.
Grade Braking is not available when the Range
Selection Mode is active. SeeTow/Haul Mode on
page 2-36While using the Range Selection mode feature, cruise
control and the Tow/Haul mode can be used.
Notice:Spinning the tires or holding the vehicle
in one place on a hill using only the accelerator
pedal may damage the transmission. The repair will
not be covered by your warranty. If you are stuck,
do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
Low Traction Mode
If your vehicle has the Allison Transmission®,orthe
Hydra-Matic®6-Speed Automatic Transmission, it has a
Low Traction Mode that assist in vehicle acceleration
when road conditions are slippery, such as with ice
or snow. While the vehicle is at a stop, select the second
gear range using the Range Selection system. This
will limit torque to the wheels after it detects wheel slip,
preventing the tires from spinning.
2-35

4m(Four-Wheel Drive High):Use the four-wheel high
position when you need extra traction, such as on
snowy or icy roads or in most off-road situations. This
setting also engages your front axle to help drive
your vehicle. This is the best setting to use when
plowing snow.
4
n(Four-Wheel Drive Low):This setting also
engages your front axle and delivers extra torque.
You may never need this setting. It sends maximum
power to all four wheels. You might choose Four-Wheel
Drive Low if you are driving off-road in deep sand,
deep mud, deep snow, and while climbing or descending
steep hills. StabiliTrak
®will not engage in this mode.
SeeStabiliTrak®System on page 4-6for more
information.
{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.
NEUTRAL (N):Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-45orTowing
Your Vehicle on page 4-45for more information.
If the SERVICE 4 WHEEL DRIVE message stays on,
you should take your vehicle to your dealer for service.
See “SERVICE 4 WHEEL DRIVE message” under
DIC Warnings and Messages on page 3-59.
2-38

Leaving Your Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave your vehicle
with the engine running. Your vehicle could
move suddenly if the shift lever is not fully in
PARK (P) with the parking brake rmly set.
If you have four-wheel drive and your transfer
case 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.
And, if you leave the vehicle with the engine
running, it could overheat and even catch re.
You or others could be injured. Do not leave
your vehicle with the engine running unless
you have to.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and
the parking brake is rmly set before you leave it.After you move the shift lever into PARK (P), hold the
regular brake pedal down. Then, see if you can
move the shift lever away from PARK (P) without rst
pulling it toward you. If you can, it means that the
shift lever was not fully locked into PARK (P).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into PARK (P) properly, the weight of the
vehicle may put too much force on the parking pawl
in the transmission. You may nd it difficult to pull the
shift lever out of PARK (P). This is called torque lock.
To prevent torque lock, set the parking brake and
then shift into PARK (P) properly before you leave the
driver’s seat. To nd out how, seeShifting Into Park
on page 2-43.
When you are ready to drive, move the shift lever out of
PARK (P) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission, then
you will be able to pull the shift lever out of PARK (P).
2-44

Brake Wear
Your vehicle has 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 can 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 the 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 can cause a brake
squeal when the brakes are rst applied or lightly applied.
This does not mean something is wrong with the 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 torque specications in
Capacities and Specifications on page 5-126.
Brake linings should always be replaced as complete
axle sets.Brake Pedal Travel
See your dealer/retailer 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 that brake service
might be required.
Brake Adjustment
Every time you make a brake stop, the disc brakes
adjust for wear.
5-46

Reset the Tire Pressure Monitor System. SeeTire
Pressure Monitor Operation on page 5-77.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-126.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush
later, if needed, to get all the rust or dirt
off. SeeChanging a Flat Tire on page 5-90.
Make sure the spare tire is stored securely. Push,
pull, and then try to rotate or turn the tire. If it
moves, tighten the cable. SeeStoring a Flat or
Spare Tire and Tools on page 5-105.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions,
inuence when you need new tires.
One way to tell when it
is time for new tires is to
check the treadwear
indicators, which appear
when your tires have only
1/16 inch (1.6 mm) or less
of tread remaining. Some
commercial truck tires may
not have treadwear
indicators.
5-81

11. Tighten the nuts rmly in a crisscross sequence as
shown by turning the wheel wrench clockwise.
{CAUTION:
Incorrect or improperly tightened wheel nuts
can cause the wheel to come loose and even
come off. This could lead to a crash. If you
have to replace them, be sure to get new
original equipment wheel nuts. Stop
somewhere as soon as you can and have the
nuts tightened with a torque wrench to the
proper torque specication. SeeCapacities
and Specifications on page 5-126for wheel
nut torque specication.Notice:Improperly tightened wheel nuts can
lead to brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper torque
specication. SeeCapacities and Specifications on
page 5-126for the wheel nut torque specication.
When you reinstall the regular wheel and tire, you must
also reinstall either the center cap or the bolt-on hub
cap, depending on which your vehicle has.
For center caps, line up the tab on the center cap
with the slot in the wheel. The cap only goes in
one way. Place the cap on the wheel and press
until it snaps into place.
For bolt-on hub caps, line up the plastic nut caps
with the wheel nuts and tighten clockwise by
hand to get them started. Then tighten with the
wheel wrench until snug.
5-101

ApplicationCapacities
English Metric
Fuel Tank
Regular 26.0 gal 98.4 L
Extended 1500 Series 31.5 gal 119.2 L
Extended 2500 Series 39.0 gal 147.6 L
Transmission Fluid
4L70-E Super Duty Transmission and 4L60-E Electronic
Transmission5.0 qt 4.7 L
4L80-E Transmission 7.7 qt 7.3 L
6L90-Transmission 6.3 qt 6.0 L
Transfer Case Fluid 2.0 qt 1.9 L
Wheel Nut Torque 140 lb ft 190Y
†Oil lter should be changed at every oil change.
All capacities are approximate. When adding, be sure to ll to the appropriate level, as recommended in this
manual. Recheck uid level after lling
5-127