Life Of Tire
The service life of a tire is dependent upon varying factors
including, but not limited to:
•Driving style.
• Tire pressure – Improper cold tire inflation pressures can
cause uneven wear patterns to develop across the tire
tread. These abnormal wear patterns will reduce tread
life, resulting in the need for earlier tire replacement.
• Distance driven.
• Performance tires, tires with a speed rating of V or
higher, and Summer tires typically have a reduced tread
life. Rotation of these tires per the vehicle maintenance
schedule is highly recommended.
WARNING!
Tires and the spare tire should be replaced after six
years, regardless of the remaining tread. Failure to
follow this warning can result in sudden tire failure.
You could lose control and have a collision resulting in
serious injury or death. Keep dismounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact with
oil, grease, and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressures. The manu-
facturer strongly recommends that you use tires equivalent
to the originals in size, quality and performance when
replacement is needed. Refer to the paragraph on “Tread
Wear Indicator” in this section. Refer to the Tire and
Loading Information placard or the Vehicle Certification
Label for the size designation of your tire. The Load Index
and Speed Symbol for your tire will be found on the
original equipment tire sidewall.
See the Tire Sizing Chart example found in the “Tire Safety
Information” section of this manual for more information
relating to the Load Index and Speed Symbol of a tire.
It is recommended to replace the two front tires or two rear
tires as a pair. Replacing just one tire can seriously affect
your vehicle’s handling. If you ever replace a wheel, make
sure that the wheel’s specifications match those of the
original wheels.
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STARTING AND OPERATING 389
It is recommended you contact your authorized tire dealer
or original equipment dealer with any questions you may
have on tire specifications or capability. Failure to use
equivalent replacement tires may adversely affect the
safety, handling, and ride of your vehicle.
WARNING!
•Do not use a tire, wheel size or rating other than that
specified for your vehicle. Some combinations of
unapproved tires and wheels may change suspen-
sion dimensions and performance characteristics,
resulting in changes to steering, handling, and brak-
ing of your vehicle. This can cause unpredictable
handling and stress to steering and suspension com-
ponents. You could lose control and have a collision
resulting in serious injury or death. Use only the tire
and wheel sizes with load ratings approved for your
vehicle.
• Never use a tire with a smaller load index or capacity,
other than what was originally equipped on your
vehicle. Using a tire with a smaller load index could
result in tire overloading and failure. You could lose
control and have a collision.
(Continued)
WARNING! (Continued)
•Failure to equip your vehicle with tires having ad-
equate speed capability can result in sudden tire
failure and loss of vehicle control.
CAUTION!
Replacing original tires with tires of a different size
may result in false speedometer and odometer read-
ings.
TIRE CHAINS (TRACTION DEVICES)
Use of traction devices require sufficient tire-to-body clear-
ance. Follow these recommendations to guard against
damage.
• Traction device must be of proper size for the tire, as
recommended by the traction device manufacturer.
390 STARTING AND OPERATING
Please follow the table below for proper tire size, chain
type, and axle recommendations:
VehicleAxle Recommendations Tire SizesChain Class
Chassis Cab 3500 (Single Rear Wheel) Models Rear Only
LT265/70R18E U Class
Chassis Cab 3500 (Dual
Rear Wheel) 4X2 Models Rear Only
LT235/80R17E U Class
Chassis Cab 3500 (Dual
Rear Wheel) 4X4 Models Front/Rear
LT235/80R17E U Class
Chassis Cab 4500/ 5500 Models Rear Only
225/70R19.5G U Class
WARNING!
Using tires of different size and type (M+S, Snow)
between front and rear axles can cause unpredictable
handling. You could lose control and have a collision.
CAUTION!
To avoid damage to your vehicle or tires, observe the
following precautions:
•Because of restricted traction device clearance be-
tween tires and other suspension components, it is
important that only traction devices in good condi-
tion are used. Broken devices can cause serious
damage. Stop the vehicle immediately if noise occurs
(Continued)
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STARTING AND OPERATING 391
The TPMS will warn the driver of a low tire pressure if the
tire pressure falls below the low-pressure warning limit for
any reason, including low temperature effects and natural
pressure loss through the tire.
The TPMS will continue to warn the driver of low tire
pressure as long as the condition exists, and will not turn
off until the tire pressure is at or above the recommended
cold placard pressure. Once the low tire pressure warning
(Tire Pressure Monitoring [TPM] Telltale Light) illumi-
nates, you must increase the tire pressure to the recom-
mended cold placard pressure in order for the “Tire
Pressure Monitoring Telltale Light” to turn off. The system
will automatically update and the “Tire Pressure Monitor-
ing Telltale Light” will turn off once the system receives the
updated tire pressures. The vehicle may need to be driven
for up to 20 minutes above 15 mph (24 km/h) in order for
the TPMS to receive this information.
For example, your vehicle may have a recommended cold
(parked for more than three hours) placard pressure of
30 psi (207 kPa). If the ambient temperature is 68°F (20°C)
and the measured tire pressure is 27 psi (186 kPa), a
temperature drop to 20°F (-7°C) will decrease the tire
pressure to approximately 23 psi (158 kPa). This tire
pressure is sufficiently low enough to turn ON the “TirePressure Monitoring Telltale Light.” Driving the vehicle
may cause the tire pressure to rise to approximately 27 psi
(186 kPa), but the “Tire Pressure Monitoring Telltale Light”
will still be ON. In this situation, the “Tire Pressure
Monitoring Telltale Light” will turn OFF only after the tires
are inflated to the vehicle’s recommended cold placard
pressure value.
CAUTION!
•
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warning have been established for the tire size
equipped on your vehicle. Undesirable system op-
eration or sensor damage may result when using
replacement equipment that is not of the same size,
type, and/or style. Aftermarket wheels can cause
sensor damage.
• Using aftermarket tire sealants may cause the Tire
Pressure Monitoring System (TPMS) sensor to be-
come inoperable. After using an aftermarket tire
sealant it is recommended that you take your vehicle
to an authorized dealership to have your sensor
function checked.
(Continued)
396 STARTING AND OPERATING
CAUTION!(Continued)
•After inspecting or adjusting the tire pressure always
reinstall the valve stem cap. This will prevent mois-
ture and dirt from entering the valve stem, which
could damage the TPMS sensor.
NOTE:
• The TPMS is not intended to replace normal tire care and
maintenance or to provide warning of a tire failure or
condition.
• The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
• Driving on a significantly under-inflated tire causes the
tire to overheat and can lead to tire failure. Under-
inflation also reduces fuel efficiency and tire tread life,
and may affect the vehicle’s handling and stopping
ability.
• The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure using an accurate tire pressure
gauge, even if under-inflation has not reached the level
to trigger illumination of the “Tire Pressure Monitoring
Telltale Light.” •
Seasonal temperature changes will affect tire pressure,
and the TPMS will monitor the actual tire pressure in the
tire.
Base System — If Equipped
The Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim mounted electronic sensors to
monitor tire pressure levels. Sensors mounted to each
wheel as part of the valve stem transmit tire pressure
readings to the receiver module.
NOTE: It is particularly important for you to check the tire
pressure in all of the tires on your vehicle monthly and to
maintain the proper pressure.
The TPMS consists of the following components:
• Receiver module
• Four TPM sensors
• TPM Telltale Light
The matching full size spare wheel and tire assembly (if
equipped) has a TPM sensor. The matching full size spare
can be used in place of any of the four road tires. The TPMS
will only monitor the pressure in the full size spare when
it is used in place of a road tire. Otherwise, a spare with a
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STARTING AND OPERATING 397
•Installing aftermarket window tinting that contains ma-
terials that may block radio wave signals.
• Accumulation of snow or ice around the wheels or
wheel housings.
• Using tire chains on the vehicle.
• Using wheels/tires not equipped with TPM sensors.
Vehicles With Non Matching Full Size Spare Or Compact
Spare
• The non matching full size spare or compact spare tire
does not have a TPM sensor. Therefore, the TPMS will
not monitor the pressure in the non matching full size
spare or compact spare tire.
• If you install the non matching full size spare or compact
spare tire in place of a road tire that has a pressure below
the low-pressure warning limit, upon the next ignition
switch cycle, the TPM Telltale Light and a “LOW TIRE”
message will remain ON and a chime will sound. In
addition, the graphic in the instrument cluster will still
display a pressure value in a different color.
• For each subsequent ignition switch cycle, a chime will
sound, the TPM Telltale Light will flash on and off for 75
seconds and then remain on solid, and the instrument cluster will display a
SERVICE TPM SYSTEM message
for a minimum of five seconds and then display dashes
(- -) in place of the pressure value.
• Once you repair or replace the original road tire and
reinstall it on the vehicle in place of the non matching
full size spare or compact spare, the TPMS will update
automatically. In addition, the TPM Telltale Light will
turn OFF and the graphic in the instrument cluster will
display a new pressure value instead of dashes (- -). The
vehicle may need to be driven for up to 20 minutes
above 15 mph (24 km/h) in order for the TPMS to
receive this information.
Tire Pressure Information System (TPIS) Chassis
Cab — If Equipped
Your vehicle may be equipped with a Tire Pressure Infor-
mation System (TPIS).
The Tire Pressure Information System (TPIS) uses wireless
technology with wheel rim mounted electronic sensors to
transmit tire pressure levels. Sensors mounted to each
wheel as part of the valve stem transmit tire pressure
readings to the receiver module.
400 STARTING AND OPERATING
Tire Size
The tire size on the Vehicle Certification Label represents
the actual tire size on your vehicle. Replacement tires must
be equal to the load capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo loaded
into the vehicle. The front and rear curb weight values are
determined by weighing your vehicle on a commercial
scale before any occupants or cargo are added.
Loading
The actual total weight and the weight of the front and rear
of your vehicle at the ground can best be determined by
weighing it when it is loaded and ready for operation.The entire vehicle should first be weighed on a commercial
scale to insure that the GVWR has not been exceeded. The
weight on the front and rear of the vehicle should then be
determined separately to be sure that the load is properly
distributed over the front and rear axle. Weighing the
vehicle may show that the GAWR of either the front or rear
axles has been exceeded but the total load is within the
specified GVWR. If so, weight must be shifted from front to
rear or rear to front as appropriate until the specified
weight limitations are met. Store the heavier items down
low and be sure that the weight is distributed equally. Stow
all loose items securely before driving.
Improper weight distributions can have an adverse effect
on the way your vehicle steers and handles and the way
the brakes operate.
CAUTION!
Do not load your vehicle any heavier than the GVWR
or the maximum front and rear GAWR. If you do, parts
on your vehicle can break, or it can change the way
your vehicle handles. This could cause you to lose
control. Also overloading can shorten the life of your
vehicle.
408 STARTING AND OPERATING
CAUTION!
Driving with a hot cooling system could damage your
vehicle. If the temperature gauge reads HOT (H), pull
over and stop the vehicle. Idle the vehicle with the air
conditioner turned off until the pointer drops back
into the normal range. If the pointer remains on HOT
(H), and you hear continuous chimes, turn the engine
off immediately and call for service.
WHEEL AND TIRE TORQUE SPECIFICATIONS
Proper lug nut/bolt torque is very important to ensure that
the wheel is properly mounted to the vehicle. Any time a
wheel has been removed and reinstalled on the vehicle, the
lug nuts/bolts should be torqued using a properly cali-
brated torque wrench.
Torque Specifications
Lug Nut/BoltTorque Lug Nut/
Bolt Type **Lug
Nut/Bolt Size Lug Nut/
Bolt
Socket Size
120-150 Ft-Lbs (160-200 N·m) Cone M14 x
1.5022 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.
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