Page 518 of 675

Towing Requirements — Tires
• Do not attempt to tow a trailer while using a compact
spare tire.
• Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to
“Tires – General Information” in “Starting And Oper-
ating” for proper tire inflation procedures.
• Check the trailer tires for proper tire inflation pres-
sures before trailer usage.
• Check for signs of tire wear or visible tire damage
before towing a trailer. Refer to “Tires – General
Information” in “Starting And Operating” for the
proper inspection procedure.
• When replacing tires, refer to “Tires – General Infor-
mation” in “Starting And Operating” for proper tire replacement procedures. Replacing tires with a higher
load carrying capacity will not increase the vehicle’s
GVWR and GAWR limits.
Towing Requirements — Trailer Brakes
WARNING!• Do not connect trailer brakes to your vehicle’s
hydraulic brake lines. It can overload your brake
system 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
distance. When towing you should allow for addi-
tional space between your vehicle and the vehicle
in front of you. Failure to do so could result in an
accident.516 STARTING AND OPERATING
Page 522 of 675
4. Push the UP or DOWN button on the steering wheel
until “TRAILER TOW” appears on the screen.
5. Push the RIGHT arrow on the steering wheel to enter
“TRAILER TOW”.
6. Push the UP or DOWN buttons until Trailer Brake
Type appears on the screen.
7. Push the RIGHT arrow and then push the UP or
DOWN buttons until the proper Trailer Brake Type
appears on the screen. 8. In a traffic-free environment, tow the trailer on a dry,
level surface at a speed of 20–25 mph (30–40 km/h)
and squeeze the manual brake control lever com-
pletely.
9. If the trailer wheels lockup (indicated by squealing
tires), reduce the GAIN setting; if the trailer wheels
turn freely, increase the GAIN setting.
Repeat steps 8 and 9 until the GAIN setting is at a point
just below trailer wheel lockup. If towing a heavier
trailer, trailer wheel lockup may not be attainable even
with the maximum GAIN setting of 10.520 STARTING AND OPERATING
Page 540 of 675
Torque Specifications
Lug Nut/Bolt
Torque Lug Nut/
Bolt
Type **Lug
Nut/Bolt
Size Lug Nut/
Bolt
Socket
Size
120-150 Ft-Lbs
(160-200 N·m) Cone M14 x
1.50 22 mm
130-160 Ft-Lbs
(190-220 N·m) Flanged
**Use only your Authorized Dealer recommended lug
nuts/bolts and clean or remove any dirt or oil before
tightening.
Inspect the wheel mounting surface prior to mounting
the tire and remove any corrosion or loose particles. NOTE: Dual wheels are flat mounted, center piloted.
The lug nuts are a two-piece assembly. When the tires are
being rotated or replaced, clean these lug nuts and add
two drops of oil at the interface between the hex and the
washer.
Two-Piece Lug Nut538 WHAT TO DO IN EMERGENCIES
Page 542 of 675

WARNING!To avoid the risk of forcing the vehicle off the jack,
do not tighten the lug nuts fully until the vehicle has
been lowered. Failure to follow this warning may
result in personal injury.
JACKING AND TIRE CHANGING
WARNING!• Do not attempt to change a tire on the side of the
vehicle close to moving traffic, pull far enough off
the road to avoid the danger of being hit when
operating the jack or changing the wheel.
• Being under a jacked-up vehicle is dangerous. The
vehicle could slip off the jack and fall on you. You
could be crushed. Never put any part of your body
under a vehicle that is on a jack. (Continued) WARNING! (Continued)• Never start or run the engine while the vehicle is
on a jack. If you need to get under a raised vehicle,
take it to a service center where it can be raised on
a lift.
• The jack is designed to use as a tool for changing
tires only. The jack should not be used to lift the
vehicle for service purposes. The vehicle should be
jacked on a firm level surface only. Avoid ice or
slippery areas.
4500/5500 Models
These vehicles do not come equipped with a jack.
NOTE: Jacking and tire changing on 4500/5500 models
should be performed by an authorized dealer, or knowl-
edgeable service personnel with the appropriate heavy
duty equipment, like a tire service company.540 WHAT TO DO IN EMERGENCIES
Page 544 of 675

Jacking Instructions
Instructions
WARNING!Carefully follow these tire changing warnings to
help prevent personal injury or damage to your
vehicle:
• Always park on a firm, level surface as far from the
edge of the roadway as possible before raising the
vehicle.
• Turn on the Hazard Warning flasher.
• Block the wheel diagonally opposite the wheel to
be raised.
• Set the parking brake firmly and set an automatic
transmission in PARK; a manual transmission in
REVERSE. (Continued) WARNING! (Continued)• Never start or run the engine with the vehicle on a
jack.
• Do not let anyone sit in the vehicle when it is on a
jack.
• Do not get under the vehicle when it is on a jack. If
you need to get under a raised vehicle, take it to a
service center where it can be raised on a lift.
• Only use the jack in the positions indicated and for
lifting this vehicle during a tire change.
• If working on or near a roadway, be extremely
careful of motor traffic.
• To assure that spare tires, flat or inflated, are
securely stowed, spares must be stowed with the
valve stem facing the ground.542 WHAT TO DO IN EMERGENCIES
Page 546 of 675

When changing a rear wheel, assemble the jack drive
tube to the jack and connect the drive tube to the
extension tube. Securely place the jack under the sway
bar bracket (unless both tires are flat on one side, then
place jack under shock bracket) facing forward in vehicle.
Connect the jack tube extension and lug wrench. Before raising the wheel off the ground, make sure that
the jack will not damage surrounding truck parts and
adjust the jack position as required.
NOTE: If the jack will not lower by turning the dial
(thumbwheel) by hand, it may be necessary to use the
jack drive tube in order to lower the jack.
4. By rotating the wheel wrench clockwise, raise the
vehicle until the wheel just clears the surface.
WARNING!Raising the vehicle higher than necessary can make
the vehicle unstable. It could slip off the jack and
hurt someone near it. Raise the vehicle only enough
to remove the tire.
5. Remove the wheel nuts and pull the wheel off. Install
the spare wheel and wheel nuts with the cone shaped
end of the nuts toward the wheel on single rear wheelRear Jacking Location544 WHAT TO DO IN EMERGENCIES
Page 549 of 675

Replace the wheel skins first using a rubber mallet. When
replacing the hub caps, tilt the cap retainer over the lug
nut bolt circle and strike the high side down with a
rubber mallet. Be sure that the hub caps and wheel skins
are firmly seated around the wheel.
Dual Rear Wheels
Slots in the wheels will assist in properly orienting the
inner and outer wheels. Align these slots when assem-
bling the wheels for best access to the tire valve on the
inner wheel. The tires of both dual wheels must be
completely off the ground when tightening to insure
wheel centering and maximum wheel clamping.
Dual wheel models require a special heavy-duty lug nut
tightening adapter (included with the vehicle) to cor-
rectly tighten the lug nuts. Also, when it is necessary to
remove and install dual rear wheels, use a proper vehicle
lifting device. NOTE: When installing a spare tire (if equipped) as part
of a dual rear wheel end combination, the tire diameter of
the two individual tires must be compared. If there is a
significant difference, the larger tire should be installed in
a front location. The correct direction of rotation for dual
tire installations must also be observed.
It is recommended that wheel stud nuts be kept torqued
to specifications at all times. Torque wheel stud nuts to
specifications at each lubrication interval.
• Retighten the wheel nuts in the same sequence to the
torques listed in the table. Go through the sequence a
second time to verify that specific torque has been
achieved. Retighten to specifications at 100 miles
(160 km) and after 500 miles (800 km).
Wheel Nuts
All wheel nuts should be tightened occasionally to elimi-
nate the possibility of wheel studs being sheared or the 6WHAT TO DO IN EMERGENCIES 547
Page 556 of 675

CAUTION! (Continued)• Revving the engine or spinning the wheels too fast
may lead to transmission overheating and failure.
It can also damage the tires. Do not spin the wheels
above 30 mph (48 km/h) while in gear (no trans-
mission shifting occurring).
WARNING!Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause damage, or
even failure, of the axle and tires. A tire could
explode and injure someone. Do not spin your vehi-
cle’s wheels faster than 30 mph (48 km/h) or for
longer than 30 seconds continuously without stop-
ping when you are stuck and do not let anyone near
a spinning wheel, no matter what the speed. EMERGENCY TOW HOOKS — IF EQUIPPED
Your vehicle may be equipped with emergency tow
hooks.
NOTE: For off-road recovery, it is recommended to use
both of the front tow hooks to minimize the risk of
damage to the vehicle.
WARNING!• Do not use a chain for freeing a stuck vehicle.
Chains may break, causing serious injury or death.
• Stand clear of vehicles when pulling with tow
hooks. Tow straps may become disengaged, caus-
ing serious injury.554 WHAT TO DO IN EMERGENCIES