
Shifting Out of Neutral
To shift the transfer case out of N (Neutral), do the
following:
1. Set the parking brake. SeeParking Brake (With
Hydraulic Brakes) on page 2-38orParking Brake
(With Air Brakes) on page 2-41for parking
brake apply procedure.
2. Apply the regular brake pedal.
3. Turn the ignition to ON/RUN with the engine off.
4. Put the transmission in N (Neutral).
5. Turn the transfer case knob to the desired shift
position (Two-Wheel High, Four-Wheel High,
Four-Wheel Low).
6. After the transfer case has shifted out of N (Neutral),
the indicator light goes out.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Verify that
the parking brake is fully released and the brake
warning light is off before driving.
7. Release the parking brake.
8. Start the engine and shift the transmission lever to
the desired position.Excessively shifting the transfer case into or out of the
different modes can cause the transfer case to enter the
shift protection mode. This protects the transfer case from
possible damage and only allows the transfer case to
respond to one shift per 10 seconds. The transfer case
can stay in this mode for up to three minutes.
Parking
{CAUTION:
If you do not park the vehicle properly, it can roll.
If you have left the engine running, it can move
very quickly. You or others could be injured. To be
sure the vehicle will not move, even when you are
on level ground, follow the steps below.
2-35

Two-Speed Rear Axle Shift Control
Operation
The rear axle shift control
switch for automatic and
manual transmissions
is located in the instrument
panel switchbank.
Press the bottom of the switch for High Range and the
top of the switch for Low Range. The switch indicator
light comes on when the High Range is selected.
Always start the vehicle in motion with the two-speed
axle in low range.
Shifting on a Downgrade
Do not shift the two-speed axle when driving on a
downgrade. The speed of the vehicle moving downhill
may make it hard to shift the axle into either Low or High
Range.
Shifting
Upshifting the Axle
To shift from Low to High Range:
1. Press the bottom of the switch to shift the axle
control from Low to High.
2. Release the accelerator pedal until the shift applies.
3. Then push the accelerator pedal.
Axle upshift can be abrupt, causing the vehicle to jerk.
Release the accelerator slowly for a smooth shift.
For manual transmissions, use the clutch while pressing
the accelerator for a smooth shift.
Downshifting the Axle
To shift from High to Low Range:
1. Press the top of the switch to shift from High to Low
Range.
2. Release the accelerator pedal.
3. Then push the accelerator pedal slowly until the
axle shifts.
2-37

{CAUTION:
It can be dangerous to get out of the vehicle
without the parking brake firmly set. The vehicle
can roll. If you have left the engine running, the
vehicle can move suddenly. You or others could
be injured. To be sure the vehicle will not move,
even when you are on fairly level ground, always
set the parking brake.
To set the hand lever parking brake, hold the regular
brake pedal down, then pull up on the handle, until
it stops.
If the ignition is on when the parking brake is set, the
brake system warning light will come on.Once the parking brake is applied, slowly remove your
foot from the regular brake pedal, while checking to
see if the vehicle moves. If the vehicle does start
to move, press the regular brake pedal and adjust the
parking brake holding force. See “Parking Brake
Adjustment” later in this section.
If the parking brake still does not set, take the vehicle to
your dealer/retailer for service.
To release the foot pedal parking brake, hold the
regular brake pedal down. Pull the brake release handle,
located just above the parking brake pedal.
To release the hand lever parking brake, hold the
regular brake pedal down and push down on the handle
until it stops.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
2-39

Notice:Over-tightening the park brake lever can
cause damage to the park brake system.
Over-tightening is possible by turning the knob
more than half a turn.
Over-tightening is similar to driving down the road with
your regular brakes applied. If the park brake system
is over-tightened the vehicle may seem sluggish
to accelerate, and/or the park brake hand lever maybe
very hard to pull up and apply the park brake.
If the park brake is over-tightened turn the knob to the
right until it stops and follow the parking brake
adjustment procedure.
Vehicles with a foot-pedal park brake system must be
serviced to make this adjustment. SeeScheduled
Maintenance on page 6-5for more information.Parking Brake (With Air Brakes)
If the vehicle has air
brakes, you will have this
parking brake. It is located
above the audio system in
the instrument panel.
Pulling it out applies the parking brake. The parking
brake light will come on when the air parking brake is
applied.
2-41

{CAUTION:
If you apply any one of the air brake parking
controls while the vehicle is moving, the rig will
stop suddenly. If you are not ready for this, you or
others could be injured. Do not apply any one of
these controls while you are driving, unless you
have to make an emergency stop.
If the air pressure drops below 60 to 70 psi
(413 to 482 kPa), the primary brake warning light and
buzzer will come on. If the air pressure drops to
35 to 45 psi (241 to 310 kPa), the red trailer air supply
knob will automatically pop out and apply the spring
brakes on the trailer.
If the air pressure drops to 35 to 45 psi (241 to 310 kPa),
the yellow park brake knob will automatically pop out
and apply the spring brakes on the truck or tractor.
If you ever have a complete loss of air so that the air
brakes automatically apply, there is a way that the
tow operator can release the parking brakes to tow the
vehicle. SeeTowing Your Vehicle on page 4-23.
Parking Brake Burnish Procedure
All vehicles which have hydraulic brakes have a parking
brake. It is recommended that the parking brake be
burnished as part of the new vehicle break-in. The
parking brake will work best after it has been burnished
following these instructions:
1. Make sure that there is no other traffic around,
bring the vehicle speed up to 20 mph (32 km/h)
and apply the parking brake. Let the vehicle come
to a complete stop. Apply the base brakes and
disengage the parking brake.
2. Repeat the burnishing procedure in Step 1 a total
of 10 times.
3. Between stops, drive the vehicle about
2.5 miles (4 km).
Notice:Driving with the parking brake on can
damage the transmission and brake system parts.
Verify that the parking brake is fully released and the
brake warning light is off before driving.
2-43

Air Suspension
The vehicle may have the Hendrickson HAS Series
single-axle air suspension which is designed for
a single-axle on-highway use. This feature is available
in 19,000 lb (8 613.3 kg), 21,000 lb (9 525.4 kg)
and 23,000 lb (10 432.6 kg) capacities.
Rear Air Suspension Dump Control
If the vehicle is equipped with the Hendrickson HAS
Series single-axle air suspension, you may have
this control. The air suspension dump control allows the
operator to lower the deck height approximately
4.5 inches (11.5 cm) from the normal frame height.
The switch to deflate and
inflate the air suspension
is located on the
instrument panel.Press the bottom of the switch to deflate the air
suspension and lower the deck height. Press the top of
the switch to return the suspension to normal deck height.
An indicator light will come on and stay on whenever
the switch is in the dump position.
Parking Over Things That Burn
{CAUTION:
Things that can burn could touch hot exhaust
parts under the vehicle and ignite. Do not park
over papers, leaves, dry grass, or other things that
can burn.
2-44

Diesel Particulate Filter
The vehicle has a Diesel Particulate Filter (DPF) as part
of the exhaust system to reduce vehicle emissions. The
DPF requires a unique exhaust tailpipe with an exhaust
cooler. The exhaust cooler mixes air with the exhaust to
lower the temperature before it leaves the tailpipe.
The DPF, the tailpipe, or other exhaust system
components must not be altered. Inspect regularly and
clean any mud or dirt from the exhaust cooler,
especially where the exhaust cooler connects to the
tailpipe and the openings where fresh air enters
the cooler. See “Exhaust System Inspection” underAt
Least Twice a Year on page 6-27.
The DPF will clean itself as part of normal operation.
Several factors including fuel consumed, hours of engine
operation and miles driven are monitored by the Engine
Control Module (ECM). The self cleaning occurs
approximately once per tank of fuel.
During self cleaning, the
green DPF indicator light
will come on. See
Diesel Particulate Filter
Warning Light on
page 3-46.To clean the filter, either drive the vehicle above 30 mph
(50 km/h) to activate self cleaning, or stop the vehicle
and perform the manual cleaning procedure. For
self cleaning, drive until the green DPF indicator light
goes off. This will take approximately 20 minutes. Once
self cleaning has started, drive until the green indicator
light goes off to complete the cleaning in a single
operation if possible.
Extended idling can cause exhaust parts and gases to
become very hot. Keep the exhaust area clear of
material that could ignite or burn. SeeParking Over
Things That Burn on page 2-44for more information.
{CAUTION:
During DPF self cleaning or during extended idling
in P (Park), the exhaust system and exhaust
gases are very hot. Things that burn could touch
hot exhaust parts under the vehicle and ignite.
You or others could be burned. Do not park, or
idle for an extended period of time, near or over
papers, leaves, dry grass, or other things that can
burn. Keep the exhaust area clear of material that
could ignite or burn. SeeParking Over Things
That Burn on page 2-44for more information.
2-46

Notice:Extended idle should be avoided because
the DPF system is not capable of self cleaning at
idle. During extended idle operation, monitor the
instrument panel telltale lights and Driver Information
Center for messages and take appropriate indicated
action. Continued idling with the warning light/
message on could cause irreversible damage to the
DPF requiring repair and possible replacement that
might not be covered by the vehicle warranty.
When the yellow DPF indicator comes on, the filter is
dirty and needs cleaning. You will also notice a change
in the exhaust sound and engine idle speed. This is
normal. If you continue to drive and the exhaust filter is
not cleaned as required, the DPF indicator will change
from yellow to red. Continuing to drive the vehicle
with the red indicator can cause filter damage.
Vehicles with DPF have specific fuel and engine oil
requirements. SeeWhat Fuel to Use on page 5-8and
Engine Oil (DURAMAX Diesel Engine) on page 5-24
orEngine Oil (Caterpillar Diesel Engine) on page 5-27or
Engine Oil (Isuzu Diesel Engine) on page 5-28or
Engine Oil (Gasoline Engine) on page 5-32for more
information on those requirements.Notice:Permanent damage can occur to the DPF
or related components if the required Ultra Low
Sulfur Diesel (15 ppm sulfur maximum) or low ash
CJ-4 engine oil is not used. This damage would
not be covered by the vehicle warranty.
For vehicles with Power Take-Off (PTO), monitor the
instrument panel cluster for lights related to the DPF.
All engines consume some amount of engine oil. Ash
is the by-product of engine oil consumption. The ash will
become trapped in the DPF over the life of the vehicle.
Eventually, the buildup of ash will restrict the exhaust
gases and the DPF will need to be cleaned or replaced.
SeeAccessories and Modifications on page 5-3for
important information if you are considering adding
accessories or modifying the vehicle.
2-47