Automatic Transmission Operation
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
If the 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.
Hydra-Matic®4-Speed
Automatic Transmission
Heavy Duty 6-Speed Automatic Transmission Shown (Light Duty Similar)
See “Range Selection Mode” later in this section.
P (Park): This position locks the rear wheels. It is the
best position to use when starting the engine because
the 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
P (Park). See Torque Lock (Automatic Transmission)
under Shifting Into Park
on page 3‑47for more
information.
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To use this feature, do the following:1. Move the shift lever to M (Manual Mode).
2. Press the plus/minus buttons, located on the steering column shift lever, to select the desired
range of gears for the current driving conditions.
When M (Manual Mode) is selected a number displays
next to the M, indicating the current gear.
This number is the highest gear that can be used.
However, the vehicle can automatically shift to lower
gears as it adjusts to driving conditions. This means
that all gears below that number are available. When
5 (Fifth) is selected, 1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle, but 6 (Sixth) 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 Range Selection
Mode is active. See
Tow/Haul Mode on page 3‑38.
While using Range Selection Mode, 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 the vehicle 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 the vehicle has the Hydra-Matic®6-Speed Automatic
Transmission, it has a Low Traction Mode that assists 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 Range Selection
Mode. This will limit torque to the wheels after it detects
wheel slip, preventing the tires from spinning.
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Grade Braking assists in maintaining desired
vehicle speeds when driving on downhill grades by
automatically implementing a shift schedule that utilizes
the engine and transmission to slow the vehicle. This
reduces wear on the braking system and increases
control of the vehicle. Grade Braking monitors vehicle
speed, acceleration, engine torque and brake pedal
usage. Using this information, it detects when the truck
is on a downhill grade and the driver desires to slow the
vehicle by pressing the brake.
Also seeTowing a Trailer
on page 5‑47for more
information.
Cruise Grade Braking (Hydra-Matic®
6-Speed Automatic Transmission)
Cruise Grade Braking assists when driving on a
downhill grade. It maintains vehicle speed by
automatically implementing a shift schedule that uses
the engine and the transmission to slow the vehicle.
Cruise Grade Braking operates while Cruise Control is
engaged in Tow/Haul mode to assist in maintaining
vehicle speed under loaded vehicle conditions.
It utilizes vehicle acceleration and deviation from
desired speed to determine the correct gear for the
operating condition. If vehicle speed is above the
desired speed the transmission will downshift to slow
the vehicle. If vehicle speed is near or below desired
speed the trans will upshift, allowing vehicle speed to
increase. While in the Range Select Mode (RSM) mode, Cruise
Grade Braking is not available.
See
Automatic Transmission Operation on page 3‑32.
Four-Wheel Drive (Two Speed
Automatic Transfer Case)
If the vehicle has four-wheel drive, you can send the
engine's driving power to all four wheels for extra
traction. Read the following before using four-wheel
drive.
Notice: Driving on clean, dry pavement in
Four-Wheel Drive High or Four-Wheel Drive Low for
an extended period of time may cause premature
wear on your vehicle's powertrain. Do not drive on
clean, dry pavement in Four-Wheel Drive High or
Four-Wheel Drive Low for extended periods of time.
While driving on clean dry pavement and during tight
turns, you may experience a vibration in the steering
system.
The vehicle has StabiliTrak
®. Shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. See StabiliTrak®System on page 5‑6.
Front Axle
The front axle engages and disengages automatically
when you shift the transfer case. Some delay for the
axle to engage or disengage is normal.
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Automatic Transfer Case
The transfer case knob is
located to the left of the
instrument panel cluster.
Use this dial to shift into and out of four-wheel drive.
You can choose among five driving settings:
Indicator lights in the switches show you which setting
you are in. The indicator lights will come on briefly when
you turn on the ignition and the last chosen setting will
stay on. If the lights do not come on, you should take
the vehicle to your dealer for service. An indicator light
will flash while shifting. It will stay on when the shift is
completed. If for some reason the transfer case cannot
make a requested shift, it will return to the last chosen
setting. 2
m(Two-Wheel Drive High):
This setting is used for
driving in most street and highway situations. The front
axle is not engaged in two-wheel drive. This setting also
provides the best fuel economy.
AUTO (Automatic Four-Wheel Drive): This setting is
ideal for use when road surface traction conditions are
variable. When driving your vehicle in AUTO, the front
axle is engaged, but the vehicle's power is primarily
sent to the rear wheels. When the vehicle's software
determines a need for more traction, the system will
transfer more power to the front wheels. Driving in this
mode results in slightly lower fuel economy than
Two-Wheel Drive High.
4
m(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 the
vehicle. This is the best setting to use when
plowing snow.
4
n(Four-Wheel Drive Low) : This setting also
engages the 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.
3-40
Leaving the Vehicle With the Engine
Running
{WARNING:
It can be dangerous to leave the vehicle with the
engine running. The vehicle could move suddenly
if the shift lever is not fully in P (Park) with the
parking brake firmly set.
If you have four-wheel drive and the transfer case
is in N (Neutral), the vehicle will be free to roll,
even if the shift lever is in P (Park). So be sure
the transfer case is in a drive gear—not in
N (Neutral).
And, if you leave the vehicle with the engine
running, it could overheat and even catch fire.
You or others could be injured. Do not leave the
vehicle with the engine running unless you
have to. If you have to leave the vehicle with the engine running,
be sure your vehicle is in P (Park) and the parking
brake is firmly set before you leave it. After you move
the shift lever into P (Park), hold the regular brake pedal
down. Then, see if you can move the shift lever away
from P (Park) without first pulling it toward you. If you
can, it means that the shift lever was not fully locked
into P (Park).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into P (Park) properly, the weight of the
vehicle may put too much force on the parking pawl
in the transmission. You may find it difficult to pull the
shift lever out of P (Park). This is called torque lock. To
prevent torque lock, set the parking brake and then shift
into P (Park) properly before you leave the driver seat.
To find out how, see
Shifting Into Park on page 3‑47.
When you are ready to drive, move the shift lever out of
P (Park) 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
P (Park).
3-48
Brake Wear
This 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 the vehicle is moving, except when
applying the brake pedal firmly.
{WARNING:
The brake wear warning sound means that soon
the brakes will not work well. That could lead to
an accident. When the brake wear warning sound
is heard, have the 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 first 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 specifications in
Capacities and Specifications on page 6‑125.
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 that brake service might be
required.
Brake Adjustment
Every brake stop, the disc brakes adjust for wear.
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Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle's tires, including the spare tire, for signs of
wear or damage. SeeWhen It Is Time for New
Tires
on page 6‑79for more information.
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km). See Scheduled Maintenance
on page 7‑3.
The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This will
ensure that your vehicle continues to perform
most like it did when the tires were new.
Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or
wheels. See When It Is Time for New Tires
on
page 6‑79
and Wheel Replacementon page 6‑84.
When rotating your vehicle's tires, always use the
correct rotation pattern shown here.
Do not include the spare tire in the tire rotation.
After the tires have been rotated, adjust the front
and rear inflation pressures as shown on the Tire
and Loading Information label. See Inflation - Tire
Pressure
on page 6‑72and Loading the Vehicleon
page 5‑29
.
Reset the Tire Pressure Monitor System. See Tire
Pressure Monitor Operation
on page 6‑74.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications
on page 6‑125.
6-78
10. Turn the wheel wrench counterclockwise to lowerthe vehicle. Lower the jack completely.
11. Tighten the nuts firmly in a crisscross sequence as shown by turning the wheel wrench clockwise.
{WARNING:
Wheel nuts that are improperly or incorrectly
tightened can cause the wheels to become
loose or come off. The wheel nuts should be
tightened with a torque wrench to the proper
torque specification after replacing. Follow the
torque specification supplied by the aftermarket
manufacturer when using accessory locking wheel
(Continued)
WARNING: (Continued)
nuts. SeeCapacities and Specificationson
page 6‑125
for original equipment wheel nut
torque specifications.
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 specification. See Capacities and
Specifications
on page 6‑125for the wheel nut
torque specification.
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.
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