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.
Care should be taken to avoid sudden accelerations when both drive
wheels are on a slippery surface.
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.
Some Dana/Spicer drive axles have a driver-controlled differential lock.
The differential lock can lock or unlock the differential when the vehicle
is moving or stopped. When extra traction is required, the differential
lock will provide full power to both axles.
When the differential is locked, the vehicle’s turning radius will increase
(vehicle will “under-steer”)
The differential can be locked or unlocked when the vehicle is moving at
a constant speed of less than 25 mph (40 km/h) and while the wheels
are not slipping. The differential must not be locked when the vehicle is
traveling down steep grades and traction is minimal.
Note: Never use the differential lock at vehicle speeds above 25 mph (40
km/h).
Note: The driver-controlled differential lock function will vary with some
transmissions.
• Vehicles equipped with an Allison 3000 Series transmission: The
differential lock and differential lock light will automatically disengage
at speeds above 25 mph (40 km/h). The differential lock will remain
off until either the vehicle is restarted or the differential lock switch is
turned off then back on.
• Vehicles equipped with a 5–speed, 6–speed or 7–speed manual:
The differential lock and differential lock light will automatically
disengage at speeds above 25 mph (40 km/h). The differential lock
will remain off until either the vehicle is restarted or the differential
lock switch is turned off then back on.
Axle conversions
It is not recommended, or approved, for axle conversions to be
performed. However, it is understood that, on occasion, aftermarket
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Automatic transmissions:
•Use LO range for when you drive
a fully loaded vehicle on a severe
grade or in congested traffic. To
activate LO range, press the
upper portion of the switch.
• Use HI range for all normal
driving conditions with a lightly
loaded or partially loaded vehicle.
To activate HI range, press the
lower portion of the switch.
Note: You cannot split-shift with an automatic transmission. Also,
downshifting above 40 mph (64 km/h) may result in transmission or axle
damage.
Shifting the axle from LO to HI range - vehicle stopped
Place the transmission in N (Neutral), then press the lower part of the switch.
Shifting the axle from LO to HI range - vehicle moving
Accelerate to approximately 35 mph (56 km/h), press the lower part of
the switch while the transmission is in N (Neutral), then release and
apply the accelerator.
Shifting the axle from HI to LO range - vehicle stopped
Place the transmission in N (Neutral), then press the upper part of the switch.
Note: Do not shift the axle to LO range with the vehicle in motion.
Split-shifting (combined axle and transmission shift - manual
transmissions only)
Split-shift sequence
Ratio
combination 1234567891011
Transmission
gear 1st 1st 2nd 2nd 3rd 3rd 4th 4th 5th 6th 6th
Axle range LO HI LO HI LO HI LO HI LO LO HI
To downshift the axle to a slower ratio and shift the transmission, shift
the transmission and move the control switch to the lower ratio before
the clutch is re-engaged.
To upshift the axle and shift the transmission, move the control switch
to a faster ratio and make the transmission shift in the usual manner.
LOW
2SPD
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•Canada
Under no circumstances should your vehicle be loaded in excess of the
GVWR or GAWR. It is the operator’s responsibility to ensure that neither
the axle capacities, spring capacities, tire capacities nor the vehicle rated
GVWR is exceeded. For tire capacities, refer to Maintenance and
Specifications chapter.
Unloaded or lightly loaded vehicles
The braking system has been designed to safely stop your vehicle when
fully loaded to its GVWR.
When operating empty or lightly loaded, sudden or hard braking
may induce wheel lockup with loss of vehicle control and the
possibility of accident and serious injury, especially on wet or slippery
road surfaces.
TRAILER TOWING
Towing a trailer places an additional load on your vehicle’s engine,
transmission, axle, brakes, tires and suspension. Inspect these
components carefully prior to and after any towing operation.
Your vehicle’s load capacity is designated by weight, not by volume, so
you cannot necessarily use all available space when loading a vehicle.
2nd unit bodies are not included in maximum trailer weight ratings. The
weight of the additional “body” must be subtracted from the maximum
trailer weight.
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Do not connect a trailer’s hydraulic brake system directly to your
vehicle’s brake system. Your vehicle may not have enough
braking power and your chances of having a collision greatly increase.
Trailer lamps
Trailer lamps are required on most towed vehicles. Your vehicle may be
equipped with one of two possible trailer wiring designs. Make sure all
running lights, brake lights, turn signals and hazard lights are working.
See your dealer or trailer rental agency for proper instructions and
equipment for hooking up trailer lamps.
Driving while you tow
When towing a trailer:
• Keep your speed no faster than 70 mph (112 km/h) during the first
500 miles (800 km) of towing a trailer, and don’t make full throttle
starts.
• Turn off the speed control. The speed control may shut off
automatically when you are towing on long, steep grades.
• Consult your local motor vehicle speed regulations for towing a trailer.
• To eliminate excessive transmission shifting, use a lower gear. This will
also assist in transmission cooling.
• Anticipate stops and brake gradually.
• Do not exceed the GCWR rating or transmission damage may occur.
Servicing after towing
If you tow a trailer for long distances, your vehicle will require more
frequent service intervals. Refer to your Scheduled Maintenance Guide
for more information.
Trailer towing tips
• Practice turning, stopping and backing up before starting on a trip to
get the feel of the vehicle trailer combination. When turning, make
wider turns so the trailer wheels will clear curbs and other obstacles.
• Allow more distance for stopping with a trailer attached.
• If you are driving down a long or steep hill, shift to a lower gear. Do
not apply the brakes continuously, as they may overheat and become
less effective.
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•The trailer tongue weight should be 10–15% of the loaded trailer
weight.
• If you will be towing a trailer frequently in hot weather, hilly
conditions, at GCW, or any combination of these factors, consider
refilling your rear axle with synthetic gear lube if not already so
equipped. Refer to Lubricant specifications in theMaintenance and
Specifications chapter for the lubricant specification. Remember that
regardless of the rear axle lube used, do not tow a trailer for the first
500 miles (800 km) of a new vehicle, and that the first 500 miles (800
km) of towing be done at no faster than 70 mph (112 km/h) with no
full throttle starts.
• After you have traveled 50 miles (80 km), thoroughly check your
hitch, electrical connections and trailer wheel lug nuts.
• To aid in engine/transmission cooling and A/C efficiency during hot
weather while stopped in traffic, place the gearshift lever in P (Park)
(if available on your automatic transmission) or N (Neutral) (manual
transmissions and automatic transmissions withou taP[Park]
position).
• Vehicles with trailers should not be parked on a grade. If you must
park on a grade, place wheel chocks under the trailer’s wheels.
FIFTH WHEEL OPERATION
Failure to follow the fifth wheel manufacturer’s instructions for
hooking and unhooking as well as sliding the fifth wheel could
result in an accident, personal injury or death.
When the tractor and trailer are parked unattended, the trailer
brake hand control should never be used to apply the brake,
since air may leak from the system, allowing vehicle movement,
resulting in possible property damage, personal injury or death.
Before hook-up, make sure:
• The fifth wheel jaws are fully opened.
• The fifth wheel is fully tilted back to prevent body damage when the
tractor is backed under a trailer.
• The trailer wheels are blocked and the trailer spring brakes are
adjusted and applied. Never chase a trailer.
• The brake hoses and light cords are clear of the fifth wheel.
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Hook-up
1.
Back the tractor squarely under the trailer, engaging the fifth wheel jaws
on the kingpin. Always back-up slowly, making sure the trailer is neither too
high nor too low. Avoid backing under the trailer from an angle.
2. Connect the service and emergency brake hoses and trailer light
connector. Refer to Tractor-trailer connection in this chapter, adhering
to the warning and using the three-point stance while connecting and
disconnecting the trailer.
3.
Inspect the jaws of the fifth wheel to be sure they have fully closed on
the trailer kingpin and the trailer plate is resting securely on the fifth wheel.
4. Be sure the coupler release lever is in the locked position.
5. Charge the trailer brake system. Set the trailer brakes, either with the
hand valve or tractor protection valve. Pull against the trailer for an
additional check of proper hook-up. Do not pull hard enough to damage
or strain the equipment.
6. Set the tractor parking brakes and fully raise the trailer landing gear.
Refer to Brakesin this chapter for proper operation of the parking brake
and trailer brakes.
7. Check the operation of all trailer lights and correct any lights that may
be faulty.
Un-hook
1. Try to keep the tractor and trailer in a straight line.
2. Apply the parking brakes.
3. Lower the trailer landing gear, making sure it is on solid, level ground.
The weight of the trailer is to be on the landing gear.
4. Block the trailer wheels.
5. Disconnect the brake hoses and light cords. Be sure hoses and cords
are clear.
6. Pull coupler release lever to disengage the fifth wheel jaws.
7. Release the tractor parking brakes.
8. Pull out from the trailer slowly, allowing the landing gear to take the
load gradually.
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Passenger compartment fuse panel
Fuse/Relay
LocationFuse Amp
RatingFuse Description
1 20A Horn
2 15A Turn/Hazard lamps
3 20A Cigar lighter
4 10A Diagnostic connectors, Power park brake
chime
5 15A Back-up lamps, DRL relays, Blend door
actuator, Heated seat module, Trailer ABS
relay, Exhaust brake, Climate mode switch
6 — Not used
7 — Not used
8 5A Radio, GEM
9 5A Switch illumination (Headlamp, Power
windows, Power door locks), Power window
relay
10 15A Heated/Lighted mirrors
11 5A Wiper motor, Washer pump relay
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capability. Attempting to push-start a vehicle with an automatic
transmission may cause transmission damage.
Before connecting a fast-charger, booster battery or installing a new
battery, make sure the ground polarities of the fast-charger, booster
battery or alternator (when installing a battery) are matched to the
ground polarity of the vehicle battery. Improper usage of the
fast-charger, hook-up of booster battery or installation of a new battery
can cause damage to the electrical system or to the alternator. Do not
attempt to polarize the alternator.
Preparing your vehicle
1.Use only a 12–volt supply to start your vehicle.Do not attach the
jumper cables to the glow plug relay as this could severely damage the
glow plugs, injector driver module and PCM.
2. Do not disconnect the battery of the disabled vehicle as this could
damage the vehicle’s electrical system.
3. Park the booster vehicle close to the hood of the disabled vehicle
making sure the two vehiclesdo nottouch. Set the parking brake on
both vehicles and stay clear of the engine cooling fan and other moving
parts.
4. Check all battery terminals and remove any excessive corrosion before
you attach the battery cables. Ensure that vent caps are tight and level.
5. Turn the heater fan on in both vehicles to protect any electrical
surges. Turn all other accessories off.
Connecting the jumper cables
1. Connect the positive (+) jumper cable to the positive (+) terminal of
the discharged battery.
Note:In the illustrations,lightning boltsare used to designate the
assisting (boosting) battery.
+–+–
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