The seat cushion height
adjustment handle is
located underneath the
front of the seat.
To adjust the height of the cushion, lift the handle up
and pull it forward. You can choose between two
settings.Chugger-Snubber Lock-Out Feature
If your vehicle has this
feature, the handle is
located on the outboard
side of the driver’s
and passenger’s seats.
Move the handle down to reduce any backslap
experienced while in tractor/trailer operation or while
operating a dump truck application.
1-7
Overdrive Defeat
If your vehicle has this feature, you can select not to
shift up to fifth gear. This is useful when towing or under
a heavy load.
The overdrive defeat
switch is located in the
instrument panel to
the right of the steering
column.
Press the switch to limit the transmission to fourth gear.
This will allow for fewer downshifts while pulling a
trailer or under a heavy load. The indicator light in the
switch will come on whenever overdrive defeat is active.
Manual Transmission Operation
Using the Clutch
When you are starting to move the vehicle, it is
important to begin with the engine speed at idle. Then
start to engage the clutch and listen for an engine speed
drop of about 100 rpm. At this point, the clutch is
engaging, so you should increase the engine speed and
fully engage the clutch. It is important not to increase
the engine speed sooner or before the clutch begins its
engagement. If you do, you can cause damage to
your vehicle.
Double-Clutching
You must use the double-clutching method when you
shift an unsynchronized gear set. Disengage the clutch,
shift to NEUTRAL and engage the clutch. When
upshifting, slow the engine until the engine rpm and
road speed match. When downshifting, accelerate the
engine until the engine rpm and road speed match. Then
quickly disengage the clutch and move the shift lever
to the next gear position and engage the clutch.
2-31
Eaton®Fuller®Five and Six-Speed
Transmissions and TTC Spicer
Seven-Speed Transmissions
These transmissions have gears that automatically
synchronize when you shift up or down (except
FIRST (1) gear on the five-speed and seven-speed
transmission which is unsynchronized). Choose the gear
that will maintain the road speed you want while
keeping the engine above two-thirds of the governed
speed. When the engine speed drops below two-thirds
of the governed speed, shift into the next lower gear
before your engine begins to lug. When you shift down,
be sure to double-clutch if required.
ZF Six-Speed Transmission
Here is how to operate your transmission.
This six-speed pattern is
unique to GM manual
transmissions.
The transmission always repositions the shift lever to
NEUTRAL, which is located between FOURTH (4)
and FIFTH (5) gear.
To prevent unintentional gear selections, additional force
is required to move the shift lever into REVERSE (R) or
FIRST (1). Use FIRST (1) when trailer towing, driving
with a heavier payload or launching on a grade.
Otherwise, start in SECOND (2) gear. Only shift into
FIRST (1) when the vehicle has stopped moving.
During the first 500 miles (805 km) of vehicle use, start
the vehicle moving in FIRST (1) gear. This allows
the clutch components to wear-in properly.
2-32
Vehicles built for use as tractors or towing vehicles have
two air brake controls. They look like this:
{CAUTION:
When the yellow PARKING BRAKE and the red
TRAILER AIR SUPPLY knobs are both pushed
in, your rig will be free to move. It could strike
someone or something. When both of these
knobs are pushed in, hold the regular brake
pedal down to keep your rig from moving.To charge a trailer’s air brake system do the following:
1. Move your vehicle into the proper position.
2. Apply the parking brake by pulling the yellow
parking brake knob out.
3. Hook up the trailer air system properly.
4. Get into the vehicle.
5. Push and hold down the regular brake pedal.
6. Push in both the yellow parking brake and the red
trailer air supply knobs. This will charge your
trailer’s air system.
After a few minutes, the trailer system should be fully
charged. When it is, the air pressure gage will show
about 125 to 135 psi (862 to 931 kPa). SeeAir Pressure
Gage on page 3-47for more information.
2-43
For driving with a trailer, the yellow and red, if equipped,
knobs must be pushed in. When you are not pulling a
trailer, the red trailer air supply knob must be pulled out.
{CAUTION:
If you apply any one of the air brake parking
controls while the vehicle is moving, your 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 light and warning
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 your 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 4-37.
Air Suspension
Your 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 your 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 in 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 dumped position.
2-44
Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-6
Other Warning Devices...................................3-6
Horn .............................................................3-6
Tilt Wheel.....................................................3-7
Turn Signal/Multifunction Lever.........................3-7
Turn and Lane-Change Signals........................3-8
Headlamp High/Low-Beam Changer..................3-8
Windshield Wipers..........................................3-9
Windshield Washer.......................................3-10
Cruise Control..............................................3-10
Exterior Lamps.............................................3-14
Headlamps on Reminder................................3-15
Daytime Running Lamps (DRL).......................3-15
Marker Lamps..............................................3-16
Instrument Panel Brightness...........................3-16
Dome Lamps ...............................................3-16
Entry Lighting...............................................3-17
Reading Lamps............................................3-17
Instrument Panel Switchbank..........................3-18
Accessory Power Outlet(s).............................3-19
Ashtray(s) and Cigarette Lighter......................3-20Climate Controls............................................3-20
Climate Control System.................................3-20
Outlet Adjustment.........................................3-24
Rear Heating System....................................3-24
Warning Lights, Gages, and Indicators............3-25
Instrument Panel Cluster................................3-26
Speedometer and Odometer...........................3-27
Trip Odometer..............................................3-27
Tachometer.................................................3-27
Engine Speed Limiter....................................3-28
Safety Belt Reminder Light.............................3-28
Safety Belt Reminder Tone............................3-28
Airbag Readiness Light..................................3-29
Airbag Off Light............................................3-30
Charging System Light..................................3-31
Voltmeter Gage............................................3-32
Service Transmission Warning Light................3-32
Range Inhibit Warning Indicator......................3-33
Brake System Warning Light..........................3-33
Anti-Lock Brake System Warning Light.............3-35
Trailer Anti-Lock Brake System Warning Light . . .3-36
Engine Coolant Temperature Gage..................3-36
Section 3 Instrument Panel
3-1
Trailer Anti-Lock Brake System
Warning Light
If your vehicle is connected
to a trailer with anti-lock
brakes, this light should
come on briefly, as a
check, when you turn on
the ignition.
When this light comes on and stays on, it means there
is something wrong in the trailer anti-lock brake
system. Have the system repaired immediately.
If an anti-lock brake system equipped trailer is not
connected, this light is not functional.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, your engine
coolant might have overheated and your engine may be
too hot. You should pull off the road, stop your vehicle
and turn off the engine as soon as possible.
SeeEngine Overheating on page 5-40. If you have a
Caterpillar
®diesel engine, also see your Caterpillar®
Operation & Maintenance Manual.
United StatesCanada
3-36
Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunken Driving.............................................4-3
Control of a Vehicle........................................4-6
Braking.........................................................4-6
Hydraulic Brake Systems.................................4-7
Anti-Lock Brake System (ABS).........................4-8
Braking in Emergencies...................................4-9
Trailer Brake Hand Control Valve....................4-10
Rear Axle Differential Lock Control..................4-11
Traction Control System (TCS).......................4-12
Steering......................................................4-13
Off-Road Recovery.......................................4-15
Passing.......................................................4-16
Loss of Control.............................................4-17
Driving at Night............................................4-18Driving in Rain and on Wet Roads..................4-20
City Driving..................................................4-23
Freeway Driving...........................................4-24
Highway Hypnosis........................................4-25
Hill and Mountain Roads................................4-26
Winter Driving..............................................4-27
If Your Vehicle is Stuck in Sand, Mud, Ice,
or Snow...................................................4-32
Rocking Your Vehicle to Get It Out.................4-32
Tow Hooks..................................................4-33
Loading Your Vehicle....................................4-34
Adding a Snow Plow or Similar Equipment.......4-36
Towing..........................................................4-37
Towing Your Vehicle.....................................4-37
Trailer Connections.......................................4-39
Section 4 Driving Your Vehicle
4-1