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WARNING!(Continued)
•Unequal tire pressures from one side of the vehicle
to the other can cause the vehicle to drift to the
right or left.
• Always drive with each tire inflated to the recom-
mended cold tire inflation pressure.
Economy
Improper inflation pressures can cause uneven wear
patterns to develop across the tire tread. These abnormal
wear patterns will reduce tread life resulting in a need for
earlier tire replacement. Under-inflation also increases
tire rolling resistance resulting in higher fuel consump-
tion.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a comfortable ride.
Over-inflation produces a jarring and uncomfortable
ride. Both under-inflation and over-inflation affect the stability of the vehicle and can produce a feeling of
sluggish response or over responsiveness in the steering.
Unequal tire pressures from side to side may cause erratic
and unpredictable steering response.
Unequal tire pressure from side to side may cause the
vehicle to drift left or right.
Tire Inflation Pressures
The proper cold tire inflation pressure is listed on the
driver’s side “B” Pillar or rear edge of the driver’s side
door.
Some vehicles may have Supplemental Tire Pressure
Information for vehicle loads that are less than the
maximum loaded vehicle condition. Refer to “Supple-
mental Tire Pressure Information” in “Starting and Op-
erating” for further information.
The pressure should be checked and adjusted as well as
inspecting for signs of tire wear or visible damage at least
5
STARTING AND OPERATING 499
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end of the wheel nuts toward the wheel. To avoid the
risk of forcing the vehicle off the jack, do not fully
tighten the wheel nuts until the vehicle has been
lowered.
6. Using the lug wrench, finish tightening the wheel nuts using a crisscross pattern. The correct wheel nut
tightness for a cone type wheel nut is 120–140 ft lbs
(160–190 N·m) torque, for a flanged type wheel nut is
130–160 ft lbs (175–215 N·m) torque. 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 the wheel center cap and remove the 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 bottle 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.
NOTE: Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated wheel nuts.
590 WHAT TO DO IN EMERGENCIES
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5. Remove the wheel nuts and pull the wheel off. Onsingle rear-wheel (SRW) trucks, install the spare wheel
and wheel nuts with the cone shaped end of the wheel
nuts toward the wheel. On 3500 dual rear-wheel
models (DRW) the wheel nuts are a two-piece assem-
bly with a flat face. Lightly tighten the wheel nuts. To
avoid the risk of forcing the vehicle off the jack, do not
fully tighten the wheel nuts until the vehicle has been
lowered.
6. Using the lug wrench, finish tightening the wheel nuts using a crisscross pattern. The correct wheel nut
tightness for a cone type wheel nut is 120–140 ft lbs
(160–190 N·m) torque, for a flanged type wheel nut is
130–160 ft lbs (175–215 N·m) torque. 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 the wheel center cap and remove the 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 bottle 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.
NOTE: Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated wheel nuts.
608 WHAT TO DO IN EMERGENCIES
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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 ensure
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 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:
1. Tighten the wheel nuts in the numbered sequence to a
snug fit.
2. Retighten the wheel nuts in the same sequence to the torques listed in the table. Go through the sequence a
Tightening Pattern
616 WHAT TO DO IN EMERGENCIES