
•
Allows upshifts by moving gearshift
lever.
• Does not downshift into first (1) gear
at high speeds; allows for first (1) gear
when vehicle reaches slower speeds.
Forced downshifts
• Allowed in drive (D) with the tow/haul
feature on or off.
• Press the accelerator to the floor.
• Allows transmission to select an
appropriate gear.
Tow/Haul Mode To activate tow/haul, press the
button on the gearshift lever
once. The TOW HAUL indicator
light illuminates in the instrument cluster.
The tow/haul feature:
• Delays upshifts to reduce the frequency
of transmission shifting.
• Provides engine braking in all forward
gears, which slows your vehicle and
assists you in controlling your vehicle
when descending a grade.
• Depending on driving conditions and
load conditions, could downshift the
transmission to slow your vehicle and
help to control your vehicle speed
when descending a hill, without
pressing the accelerator pedal. Tapping
the brake pedal downshifts the
transmission to provide additional
braking, only if the downshift does not
cause an engine overspeed condition.
The tow/haul feature improves
transmission operation when towing a
trailer or a heavy load. All transmission
gear ranges are available when using
tow/haul. Note:
Under certain conditions, the
automatic tow/haul feature engages and
the TOW HAUL indicator comes on without
pressing the Tow/Haul button.
To deactivate the tow/haul feature and
return to normal driving mode, press the
button on the gearshift lever twice. The
TOW HAUL light deactivates. Tow/haul
also deactivates when you power down
your vehicle. WARNING: Do not use tow/haul
when the road surface is slippery. Failure
to follow this instruction could result in
the loss of control of your vehicle. WARNING:
Do not use diesel
engine exhaust braking when the road
surface is slippery. Failure to follow this
instruction could result in the loss of
control of your vehicle.
Understanding your SelectShift™
Automatic transmission
(If Equipped)
Your vehicle is equipped with a SelectShift
Automatic transmission gearshift lever.
SelectShift Automatic transmission gives
you the ability to change gears up or down
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Automatic Transmission Adaptive
Learning
This feature's design is to increase
durability and provide consistent shift feel
over the life of your vehicle. A new vehicle
or transmission could have firm shifts, soft
shifts or both. This operation is normal and
does not affect function or durability of the
transmission. Over time, the adaptive
learning process fully updates transmission
operation. Additionally, whenever you
disconnect the battery or install a new
battery, the system must relearn the
strategy.
Brake-Shift Interlock
WARNING: Do not drive your
vehicle until you verify that the
stoplamps are working. WARNING:
When doing this
procedure, you need to take the
transmission out of park (P) which
means your vehicle can roll freely. To
avoid unwanted vehicle movement,
always fully apply the parking brake prior
to doing this procedure. Use wheels
chocks if appropriate. WARNING:
If the parking brake is
fully released, but the brake warning
lamp remains illuminated, the brakes
may not be working properly. Have your
vehicle checked as soon as possible.
Your vehicle is equipped with a brake-shift
interlock feature that prevents the
gearshift lever from moving from park (P)
when the ignition is in the 3 (on) position
and the brake pedal is not pressed. If you cannot move the gearshift lever out
of park (P) position with the ignition in the
4 (on) position and the brake pedal
pressed, a malfunction could have
occurred. It is possible that a fuse has
blown or your vehicle
’s brake lamps are
not operating properly.
See Fuse
Specification Chart (page 167).
If the fuse is not blown and the brake
lamps are working properly, the following
procedure allows you to move the gearshift
lever from park (P):
1. Apply the parking brake. Switch the ignition key to 1 (off), then remove the
key.
2. Move the steering column to the full down and full rearward position
(toward the driver ’s seat).
3. Remove the gearshift lever boot.
4. Place fingers into hole where you removed the gearshift lever boot and
pull top half of shroud up and forward
to separate it from the lower half of the
shroud. There is a hinge at the forward
edge of the top shroud. Roll the top
half of the shroud upward on the hinge
point to clear the hazard flasher button,
then pull straight rearward toward the
driver ’s seat to remove.
5. Remove the top half of the shroud.
6. Remove the three fasteners under the column that secure the lower shroud
half to the column.
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GENERAL INFORMATION
WARNING: Exceeding these
ratings by overloading can cause
component failure resulting in property
damage, personal injury or death.
Fluid Temperature
If the operating temperature exceeds
250°F (121°C)
, the rate of axle lubrication
oxidation increases and shortens the life
of the lubricant and seals, requiring axle
lubrication changes to become more
frequent to preserve the axle. Do not
consistently run extreme pressure (EP)
lubricants above
250°F (121°C).
Axle Conversions WARNING:
When operating a
loaded vehicle, the driver must keep all
adjustable axles on the ground at all
times, supporting their share of the
vehicle ’s load. Failure to do so can
overload other axles, tires, wheels,
springs, steering components, brakes
and frames, resulting in early component
failure, loss of vehicle control, possible
property damage and personal injury.
We do not recommend, or approve,
performing axle conversions. However, we
understand that, on occasion, others install
aftermarket add-on axles on the truck
chassis that allow operator control for
weight transfer from other axles (such as
air lift axles). LIMITED SLIP DIFFERENTIAL
(IF EQUIPPED) WARNING:
If both wheels are not
raised off the ground, the one wheel that
is not raised may pull the vehicle off its
support, possibly resulting in personal
injury.
This axle provides added traction on
slippery surfaces, particularly when one
wheel is on a poor traction surface. Under
normal conditions, the limited-slip axle
functions like a standard rear axle. The axle
may exhibit a slight noise or vibration
during tight turns with low vehicle speed.
This is normal behavior and indicates the
axle is working.
Both wheels must be raised off the ground
should it be necessary to operate one
wheel with your vehicle stationary.
ELECTRONIC LOCKING
DIFFERENTIAL
(IF EQUIPPED)
Driver-Controlled Locking
Differential
Note: Never use the differential lock at
vehicle speeds above
25 mph (40 km/h).
Some drive axles have a driver-controlled
differential lock. The differential lock can
lock or unlock the differential when your
vehicle is moving or stopped. When extra
traction is required, the differential lock
provides full power to both wheels.
When you lock the differential, your
vehicle ’s turning radius increases
(under-steer).
Take care to avoid sudden accelerations
when both drive wheels are on a slippery
surface.
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WARNING: Sudden accelerations
on slippery surfaces could cause the
wheels to spin, the vehicle to turn
sideways on a crowned road surface or
in a turn, possibly resulting in loss of
vehicle control and personal injury.
Activating the Locking Differential
You can lock and unlock the differential
when your vehicle is moving at a constant
speed of less than 25 mph (40 km/h) and
while the wheels are not slipping. Do not
lock the differential when your vehicle is
traveling down steep grades and when
traction is minimal.
The differential lock and differential lock
light automatically disengage at speeds
above 25 mph (40 km/h). The differential
lock remains off until either you restart your
vehicle or you turn the differential lock
switch off then back on.
Servicing a Vehicle with a Locking
Differential
Turn the engine off and raise all drive
wheels of the locker differential axle in
order to prevent your vehicle from moving
when servicing the wheels, tires or brakes.
Axles equipped with a driver-controlled
differential deliver power to both wheels
even when only one wheel is on the ground. WARNING: Failure to raise all drive
wheels with this type of differential could
cause the vehicle to move unexpectedly,
resulting in property damage, personal
injury or death. 2-SPEED REAR AXLE (IF EQUIPPED) WARNING:
Never shift a
two-speed axle when descending a
steep grade as this may cause loss of
vehicle control and result in personal
injury.
Note: Do not shift between ranges when
the speed control is on.
A two-speed rear axle allows the driver to
select a low range for greater pulling power
and a high range for greater road speed
and fuel economy. You can also use these
ranges to provide extra steps between
transmission shifts when driving on steep
grades or fuel economy may be factors.
Axle Shifting Note:
Do not shift the axle to LOW when
your vehicle is moving. Use LOW when you
drive a fully loaded vehicle on a severe grade
or in congested traffic. Use HIGH for all
normal driving conditions with a lightly
loaded or partially loaded vehicle.
Note: The axle is set to HIGH by default.
To shift the axle between HIGH and LOW
with the vehicle stopped, place the
transmission in position N, then press and
hold the button for two seconds.
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GENERAL INFORMATION
WARNING: Do not apply the brake
pedal and accelerator pedal
simultaneously. Applying both pedals
simultaneously for more than a few
seconds will limit engine performance,
which may result in difficulty maintaining
speed in traffic and could lead to serious
injury.
Note: Occasional brake noise is normal. If
a metal-to-metal, continuous grinding or
continuous squeal sound is present, the
brake linings may be worn-out. Have the
system checked as soon as possible. If your
vehicle has continuous vibration or shudder
in the steering wheel while braking, have it
checked by an authorized dealer.
All standard equipment brakes are
self-adjusting. Automatic adjustment,
when required, occurs whenever you apply
and release the brakes during forward or
reverse operation.
Know the required stopping distances for
all driving conditions you may encounter.
For longer brake lining life, take full
advantage of engine braking power when
coming to a stop.
Wet brakes result in reduced braking
efficiency. Gently press the brake pedal a
few times when driving from a car wash or
standing water to dry the brakes.
If the brakes do not grip well:
• Check brake adjustment.
• Check the brake linings for excessive
wear.
• Check the system air pressure on
vehicles with air brakes. •
Let the brakes cool if you have been
using them excessively, as in mountain
driving or after several fast, high-speed
stops.
• If you have been driving through deep
water, gently apply the brakes several
times while your vehicle is moving
slowly.
Brake Over Accelerator
In the event the accelerator pedal
becomes stuck or entrapped, apply steady
and firm pressure to the brake pedal to
slow the vehicle and reduce engine power.
If you experience this condition, apply the
brakes and bring your vehicle to a safe
stop. Move the transmission to park (P),
switch the engine off and apply the parking
brake. Inspect the accelerator pedal for
any interference. If none are found and the
condition persists, have your vehicle towed
to the nearest authorized dealer
Anti-lock Brake System
This system helps you maintain steering
control during emergency stops by keeping
the brakes from locking. This lamp momentarily
illuminates when you switch the
ignition on. If the light does not
illuminate during start up, remains on or
flashes, the system may be disabled. Have
the system checked by an authorized
dealer. If you connect a PLC trailer with
the ignition on, the trailer ABS
light also illuminates. If the light
fails to illuminate, if it remains on after you
start the vehicle or continues to flash, have
the system serviced immediately.
See
Warning Lamps and Indicators
(page 60).
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If the system is disabled, normal
braking is still effective. If the
brake warning lamp illuminates
when you release the parking brake, have
the system checked by an authorized
dealer. It also illuminates momentarily
when you switch the ignition on to confirm
the lamp is functional. If it does not
illuminate when you switch the ignition on,
or begins to flash at any time, have the
system checked by an authorized dealer.
HINTS ON DRIVING WITH
ANTI-LOCK BRAKES
The anti-lock braking system does not
eliminate the risks when:
• You drive too closely to the vehicle in
front of you.
• Your vehicle is hydroplaning.
• You take corners too fast.
• The road surface is poor.
Note: If the system activates, the brake
pedal may pulse and may travel further.
Maintain pressure on the brake pedal. You
may also hear a noise from the system. This
is normal.
PARKING BRAKE
Hydraulic Brakes (If Equipped) WARNING:
Always set the parking
brake and leave your vehicle with the
transmission in park (P). WARNING:
This control is for
parking only. Do not leave the vehicle
unattended after setting the parking
brake without placing the transmission
in park (P). We recommend using wheel
chocks for hilly or off-road
circumstances. WARNING:
Unexpected and
possibly sudden vehicle movement may
occur if you do not take these
precautions. WARNING:
If the parking brake is
fully released, but the brake warning
lamp remains illuminated, the brakes
may not be working properly. Have your
vehicle checked as soon as possible.
Apply the parking brake whenever the
vehicle is parked. To set the parking brake,
pull the handle up until it snaps into the
locked position.
When the parking brake is out of
adjustment, seek service immediately. The parking brake warning lamp
in the instrument cluster
illuminates, and remains
illuminated (when you switch on the
ignition), until you release the parking
brake. 123
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Push the palm release lever (A) on the
parking brake handle (B) and push down
as far as possible to release the brake.
Driving with the parking brake on causes
the brakes to wear out quickly and reduces
fuel economy.
We recommend you not use the parking
brake to stop a moving vehicle. However,
if the normal brakes fail, you can use the
parking brake to stop your vehicle in an
emergency. Since the parking brake only
applies retardation to the rear wheels, the
vehicle's stopping distance increases
greatly and the handling of your vehicle is
adversely affected.
Releasing Spring Manually
WARNING: Do not attempt to
disassemble the parking brake air
chamber under any circumstances as
this may cause serious injury. WARNING:
Block the wheels to
help prevent the vehicle from moving. WARNING:
Unexpected and
possibly sudden vehicle movement may
occur if you do not take these
precautions.
If you release hydraulic pressure from the
spring brake chamber, the power spring
applies the brake. If the hydraulic pressure
can be re-established, you must release
the spring brake in order to move your
vehicle. Air Brakes
(If Equipped) WARNING:
This control is for
parking only. Do not leave the vehicle
unattended after setting the parking
brake without placing the transmission
in park (P). We recommend using wheel
chocks for hilly or off-road
circumstances.
If the service brakes fail to operate while
your vehicle is moving, you can make an
emergency stop with the parking brake.
Since the parking brake only applies
stopping power to the rear wheels, your
vehicle ’s stopping distance greatly
increases and the handling of your vehicle
is adversely affected. Make repairs
immediately to an inoperative air brake
system circuit. Pull the yellow, dash-mounted parking
brake knob to apply the parking brake.
The parking brake light
illuminates and remains
illuminated (when you switch
the ignition to the on position) until you
release the parking brake.
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Releasing the Parking Brake
WARNING: When your vehicle is
stationary, keep the brake pedal fully
pressed when shifting gears. Failure to
follow this instruction could result in
personal injury, death or property
damage.
Note: Read and understand the following
steps and perform them whenever you
prepare to drive the vehicle.
Note: The parking brake does not disengage
unless sufficient system air pressure is
available.
1. Press and hold the service brake pedal
while the engine is running.
2. Select the appropriate drive gear.
3. Push and hold the yellow dash-mounted parking brake knob until
the parking brake light turns off, then
release.
Parking Brake Light Illumination Due
to Low Air Pressure
If the air pressure becomes too low at any
time during vehicle operation, the parking
brake may apply and the parking brake
light turns on.
If the parking brake applies due to low air
pressure, immediate service is required to
the parking brake system.
Releasing Spring Brake with Air
Pressure
The air system in all vehicles with
spring-actuated rear wheel parking brakes
has a valve on the governor for connection
to an outside air supply. The valve lets you
recharge the system with air from an
outside source, releasing the
spring-actuated parking brakes. Your
vehicle is now ready to tow in an
emergency. You can only use an outside air source if
the protected system is in operating
condition. If you cannot restore air pressure
in the protected air system, you must
release the spring-actuated brakes
manually.
Releasing Spring Manually
Do not use impact wrenches as they may
damage the piston and prevent proper
caging of the spring. Do not apply more
than
50 lb.ft (68 Nm) to the release bolt
nut.
1. Remove the stud tool and nut from the
carrying pocket on the brake chamber
assembly. 2. Remove the access plug from the end
of the spring chamber.
3. Insert the release stud through the opening in the chamber and into the
spring pressure plate. 4.
Turn the release stud ¼ turn to engage
the stud tangs with the slot in the
pressure plate. Keep the stud engaged
and install the nut on the release stud.
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