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engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
²Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.
²Keep the liftgate closed when driving your vehicle to
prevent carbon monoxide and other poisonous ex-
haust gases from entering the vehicle.
Fuel Requirements (6.7L Diesel Engines)
Use good quality diesel fuel from a reputable supplier in
your vehicle. Federal law requires that you must fuel this
vehicle with Ultra Low Sulfur Highway Diesel fuel (15
ppm Sulfur maximum) and prohibits the use of Low
Sulfur Highway Diesel fuel (500 ppm Sulfur maximum)to avoid damage to the emissions control system. For
most year-round service, No. 2 diesel fuel meeting ASTM
specification D-975 Grade S15 will provide good perfor-
mance. If the vehicle is exposed to extreme cold (below
20ÉF or -7ÉC), or is required to operate at colder-than-
normal conditions for prolonged periods, use climatized
No. 2 diesel fuel or dilute the No. 2 diesel fuel with 50%
No. 1 diesel fuel. This will provide better protection from
fuel gelling or wax-plugging of the fuel filters.
WARNING!
Do not use alcohol or gasoline as a fuel blending
agent. They can be unstable under certain conditions
and hazardous or explosive when mixed with diesel
fuel.
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þAn electronically actuated trailer brake controller is
required when towing a trailer with electronically
actuated brakes. When towing a trailer equipped with
a hydraulic surge actuated brake system, an electronic
brake controller is not required.
þTrailer brakes are recommended for trailers over 1,000
lbs (454 kg) and required for trailers in excess of 2,000
lbs (907 kg).
CAUTION!
If the trailer weighs more than 1,000 lbs (454 kg)
loaded, it should have its own brakes and they
should be of adequate capacity. Failure to do this
could lead to accelerated brake lining wear, higher
brake pedal effort, and longer stopping distances.
WARNING!
Do not connect trailer brakes to your vehicle's hy-
draulic brake lines. It can overload your brake sys-
tem and cause it to fail. You might not have brakes
when you need them and could have an accident.
Towing any trailer will increase your stopping dis-
tance. When towing you should allow for additional
space between your vehicle and the vehicle in front
of you. Failure to do so could result in an accident.
Towing Requirements Ð Trailer Lights & Wiring
Whenever you pull a trailer, regardless of the trailer size,
stop lights and turn signals on the trailer are required for
motoring safety.
Twelve trailer tow circuits are provided at the rear of the
chassis. These circuits are unterminated and sealed.
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Trailer Tow Additional Lamp Loads
Output
FunctionsMaximum
CurrentAdditional Bulbs
Allowed Example
Only. Other bulb
combinations can
be used as long as
maximum current
is not exceeded.
Stop/Turn Left 16A2 #3157 bulbs for
stop/turn
Stop/Turn
Right16A2 #3157 bulbs for
stop/turn
Trailer Park
Lamps14A2 #1157 bulbs (two
filament park/
stop/turn) plus up
to 24 #168 or #194
peanut bulbs.Towing Tips
Before setting out on a trip, practice turning, stopping
and backing the trailer in an area away from heavy
traffic.
If using a manual transmission vehicle for trailer towing,
all starts must be in FIRST gear to avoid excessive clutch
slippage.
Towing Tips Ð Automatic Transmission
The ªDº range can be selected when towing. However, if
frequent shifting occurs while in this range, the ªTOW
HAULº or ªOD/OFFº range should be selected.
NOTE:Using the ªTOW HAULº or ªOD/OFFº range
while operating the vehicle under heavy operating con-
ditions will improve performance and extend transmis-
sion life by reducing excessive shifting and heat build up.
This action will also provide better engine braking.
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The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See Maintenance
Schedule in section 8 of this manual for transmission
fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Tow/Haul (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the ªTOW HAUL OD/OFFº feature ON when
driving in hilly areas or shift the transmission to Drive
position 2 on more severe grades.
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
þHighway Driving
Reduce speed.
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Vehicle front end wheel alignment was set to specifica-
tions at the factory without consideration for the weight
of the plow. Front end tow-in should be checked and
reset if necessary at the beginning and end of the
snowplow season. This will help prevent uneven tire
wear.
The blade should be lowered whenever the vehicle is
parked.
Maintain and operate your vehicle and snowplow equip-
ment following the recommendations provided by the
specific snowplow manufacturer.
Over the Road Operation With Snowplow
Attached
The blade restricts air flow to the radiator and causes the
engine to operate at higher than normal temperatures.
Therefore, when transporting the plow, angle the blade
completely and position it as low as road or surfaceconditions permit. Do not exceed 40 mph (64 km/h). The
operator should always maintain a safe stopping distance
and allow adequate passing clearance.
Methods For Removing Snow
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²Do not shift the transmission unless the engine has
returned to idle and wheels have stopped. Make a
practice of stepping on the brake pedal before shifting
the transmission.
RECREATIONAL TOWING (BEHIND
MOTORHOME, ETC.)
Recreational Towing ± 2 Wheel Drive Models
Recreational towing of 2 Wheel Drive models is not
allowed.Towing with the rear wheels on the ground can
result in severe transmission damage.
Recreational Towing ± 4 Wheel Drive Models
CAUTION!
Failure to follow these requirements can cause severe
damage to the transmission and/or transfer case.
CAUTION!
Internal damage to the transfer case will occur if a
front or rear wheel lift is used when recreational
towing.
NOTE:Both the Manual Shift and Electronic Shift
transfer cases must be shifted into Neutral (N) for
recreational towing. Automatic transmissions must be
placed in P (Park) position for recreational towing.
Manual transmissions must be left in gear (not in neutral)
for recreational towing. Refer below for the proper trans-
fer case Neutral shifting procedure for your vehicle.
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Recreational Towing Procedure Ð Manual Shift
Transfer Case Ð If Equipped
Use the following procedure to prepare your vehicle for
recreational towing:
CAUTION!
It is necessary to follow these steps to be certain that
the transfer case is fully in N (NEUTRAL) before
recreational towing to prevent damage to internal
parts.
1. Bring the vehicle to a complete stop.
2. Shut OFF the engine.
3. Depress the brake pedal.
4. Shift automatic transmission to N (NEUTRAL), or
depress the clutch on manual transmissions.5. Shift transfer case lever into N (NEUTRAL).
6. Start the engine.
7. Shift automatic transmission into Reverse (R).
8. Release brake pedal for five seconds and ensure that
there is no vehicle movement.
9. Repeat steps 7 and 8 with the transmission in Drive
(D).
10. Shut OFF the engine and place the ignition key to the
unlocked OFF position.
11. Shift automatic transmission into P (PARK).
12. Apply the parking brake.
13. Attach vehicle to tow vehicle with tow bar.
14. Release the parking brake.
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CAUTION!
Damage to the automatic transmission may occur if
the transmission is shifted into P (PARK) with the
transfer case in N (NEUTRAL) and the engine RUN-
NING. With the transfer case in N (NEUTRAL)
ensure that the engine is OFF prior to shifting the
transmission into P (PARK)
Returning to Normal Operation Ð Manual Shift
Transfer Case
Use the following procedure to prepare your vehicle for
normal usage:
1. Bring the vehicle to a complete stop.
2. Apply the parking brake.
3. Shut OFF the engine.4. Depress the brake pedal.
5. Shift automatic transmission to N (NEUTRAL), or
depress the clutch on manual transmissions.
6. Shift transfer case lever to desired position.
7. Shift automatic transmission into P (Park).
WARNING!
You or others could be injured if you leave the
vehicle unattended with the transfer case in the N
(NEUTRAL) position without first fully engaging the
parking brake. The transfer case N (NEUTRAL) po-
sition disengages both the front and rear driveshafts
from the powertrain and will allow the vehicle to
move regardless of the transmission position. The
parking brake should always be applied when the
driver is not in the vehicle.
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