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a collision if they have been damaged (i.e., bent retractor,
torn webbing, etc.). If there is any question regarding belt
or retractor condition, replace the belt.
Airbag Warning Light
The light should come on and remain on for six to eight
seconds as a bulb check when the ignition switch is first
turned ON. If the light is not lit during starting, see your
authorized dealer. If the light stays on, flickers, or comes
on while driving, have the system checked by an autho-
rized dealer.
Defroster
Check operation by selecting the defrost mode and place
the blower control on high speed. You should be able to
feel the air directed against the windshield. See your
authorized dealer for service if your defroster is
inoperable.
Periodic Safety Checks You Should Make Outside
the Vehicle
Tires
Examine tires for excessive tread wear and uneven wear
patterns. Check for stones, nails, glass, or other objects
lodged in the tread. Inspect the tread and sidewall for
cuts and cracks. Check the wheel nuts for tightness.
Check the tires (including spare) for proper pressure.
Lights
Have someone observe the operation of exterior lights
while you work the controls. Check turn signal and high
beam indicator lights on the instrument panel.
Door Latches
Check for positive closing, latching, and locking.
2
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 75
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To check if tires are even, lay a straight edge across all
four tires. The straight edge should touch all the tires.
CAUTION!
4500/5500 Dual Rear Tires have only one approved
direction of rotation. This is to accommodate the
asymmetrical design (tread pattern) of the On/Off
road tire.
•When replacing a flat, the spare tire may have to
be remounted on the rim or installed at a different
location to maintain the correct placement of the
tire on the wheel relative to the tire/wheel position
on the vehicle. For example, if the spare is used to
replace an outer rear tire it will have to be re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires will maintain proper position.
FUEL REQUIREMENTS
The 5.7L engine is designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high-quality unleaded gasoline hav-
ing an octane range of 87 to 89. The manu-
facturer recommends the use of 89 octane
for optimum performance. The use of premium gasoline
is not recommended, as it will not provide any benefit
over regular gasoline in these engines.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of “regular” gasoline be-
fore considering service for the vehicle.
5
STARTING AND OPERATING 321
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WARNING! (Continued)
•To assure that spare tires, flat or inflated, are
securely stowed, spares must be stowed with the
valve stem facing the ground.
•Turn on the Hazard Warning flasher.
1. If equipped, remove the spare wheel, jack, and tools
from storage.
2. Using the wheel wrench, loosen, but do not remove,
the wheel nuts by turning them counterclockwise one
turn while the wheel is still on the ground. 3. When changing the front wheel, assemble the jack
drive tube to the jack and connect the drive tube to the
extension tube. Place the jack under the axle as close to
the tire as possible with the drive tubes extending to the
front. Connect the jack tube extension and wheel wrench.
Jack Warning Label
Front Jacking Locations
362 WHAT TO DO IN EMERGENCIES
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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 wheel (SRW)
models. On dual rear wheel models (DRW) the lug nuts
are a two-piece assembly with a flat face. Lightly tighten
the nuts. To avoid risk of forcing the vehicle off the jack,
do not fully tighten the nuts until the vehicle has been
lowered.
6. Using the wheel wrench, finish tightening the nuts
using a crisscross pattern. The correct nut tightness is
135 ft lbs (183 N·m) torque for single rear wheel (SRW)
models and 145 ft lbs (197 N·m) for dual rear wheel
models. If in doubt about the correct tightness, have them
checked with a torque wrench by your authorized dealer
or at a service station.WARNING!
A loose tire or jack thrown forward in a collision or
hard stop could injure someone in the vehicle. Al-
ways stow the jack parts and the extra tire and wheel
in the places provided.
7. Install wheel center cap (if equipped) and remove
wheel blocks. Do not install chrome or aluminum wheel
center caps on the spare wheel. This may result in cap
damage.
8. Lower the jack to its fully closed position. 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. Stow the replaced tire, jack, and tools as
previously described.
9. Adjust the tire pressure when possible.
364 WHAT TO DO IN EMERGENCIES
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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.
These dual rear wheels should be tightened as follows:
Tightening Pattern (8 Studs)6
WHAT TO DO IN EMERGENCIES 367
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Wheel Nut Torque
All wheel nuts should be tightened occasionally to elimi-
nate the possibility of wheel studs being sheared or the
bolt holes in the wheels becoming elongated. This is
especially important during the first few hundred miles/
kilometers of operation to allow the wheel nuts to
become properly set. All nuts should first be firmlyseated against the wheel. The nuts should then be
tightened to recommended torque. Tighten the nuts to
final torque in increments. Progress around the bolt
circle, tightening the nut opposite to the nut just previ-
ously tightened until final torque is achieved. Recom-
mended torques are shown in the following chart.
Disc Wheels Type Nut
Stud SizeTorque Ft Lbs Torque Newton
Meters
Cone 9/16-18120-150160-200
Flanged 9/16-18130-160190-220
To Stow The Flat Or Spare — If Equipped
Refer to Upfitters Body Builders Guide for information
on stowing your spare tire (if equipped).
6
WHAT TO DO IN EMERGENCIES 369