SERVICING AND MAINTENANCE433
Tire Terminology And Definitions
Tire Loading And Tire Pressure
NOTE:
The proper cold tire inflation pressure is listed
on the driver’s side B-Pillar or the rear edge of
the driver's side door.
Check the inflation pressure of each tire,
including the spare tire (if equipped), at least
monthly and inflate to the recommended
pressure for your vehicle.
Example Tire Placard Location (Door)Example Tire Placard Location (B-Pillar)
Term Definition
B-PillarThe vehicle B-Pillar is the structural member of the body located behind the front door.
Cold Tire Inflation Pressure Cold tire inflation pressure is defined as the tire pressure after the vehicle has not been
driven for at least three hours, or driven less than 1 mile (1.6 km) after sitting for a
minimum of three hours. Inflation pressure is measured in units of PSI (pounds per
square inch) or kPa (kilopascals).
Maximum Inflation Pressure The maximum inflation pressure is the maximum permissible cold tire inflation pressure
for this tire. The maximum inflation pressure is molded into the sidewall.
Recommended Cold Tire Inflation Pressure Vehicle manufacturer's recommended cold tire inflation pressure as shown on the tire
placard.
Tire Placard A label permanently attached to the vehicle describing the vehicle’s loading capacity,
the original equipment tire sizes and the recommended cold tire inflation pressures.
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434SERVICING AND MAINTENANCE
Tire And Loading Information Placard
Tire And Loading Information Placard
This placard tells you important information
about the:
1. Number of people that can be carried in the vehicle.
2. Total weight your vehicle can carry.
3. Tire size designed for your vehicle.
4. Cold tire inflation pressures for the front, rear, and spare tires.Loading
The vehicle maximum load on the tire must not
exceed the load carrying capacity of the tire on
your vehicle. You will not exceed the tire's load
carrying capacity if you adhere to the loading
conditions, tire size, and cold tire inflation
pressures specified on the Tire and Loading
Information placard in “Vehicle Loading” in the
“Starting And Operating” section of this manual.
NOTE:
Under a maximum loaded vehicle condition,
gross axle weight ratings (GAWRs) for the front
and rear axles must not be exceeded.
For further information on GAWRs, vehicle
loading, and trailer towing, refer to “Vehicle
Loading” in the “Starting And Operating”
section of this manual.
To determine the maximum loading conditions
of your vehicle, locate the statement “The
combined weight of occupants and cargo
should never exceed XXX kg or XXX lbs” on the
Tire and Loading Information placard. The
combined weight of occupants, cargo/luggage
and trailer tongue weight (if applicable) should
never exceed the weight referenced here.
Steps For Determining Correct Load
Limit—
(1) Locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kg or XXX lbs.” on your
vehicle's placard.
(2) Determine the combined weight of
the driver and passengers that will be
riding in your vehicle.
(3) Subtract the combined weight of the
driver and passengers from XXX kg or
XXX lbs.
(4) The resulting figure equals the
available amount of cargo and luggage
load capacity. For example, if “XXX”
amount equals 1400 lbs. and there will
be five 150 lb passengers in your
vehicle, the amount of available cargo
and luggage load capacity is 650 lbs.
(1400-750 (5x150) = 650 lbs.)
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SERVICING AND MAINTENANCE439
(Continued)
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 replace -
ment.
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 scheduled maintenance is
highly recommended. NOTE:
Wheel valve stem must be replaced as well
when installing new tires due to wear and tear
in existing tires.
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 manufacturer
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
Indicators” 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.
It is recommended you contact an 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!
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.
WARNING!
Do not use a tire, wheel size, load rating, or
speed rating other than that specified for
your vehicle. Some combinations of unap
-
proved tires and wheels may change
suspension dimensions and performance
characteristics, resulting in changes to
steering, handling, and braking of your
vehicle. This can cause unpredictable
handling and stress to steering and
suspension components. 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.
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SERVICING AND MAINTENANCE441
SPARE TIRES — IF EQUIPPED
Refer to the “Towing Requirements - Tires” in
“Starting And Operating” for restrictions when
towing with a spare tire designated for
temporary emergency use.
Spare Tire Matching Original Equipped Tire
And Wheel — If Equipped
Your vehicle may be equipped with a spare tire
and wheel equivalent in look and function to the
original equipment tire and wheel found on the
front or rear axle of your vehicle. This spare tire
may be used in the tire rotation for your vehicle.
If your vehicle has this option, refer to an
authorized tire dealer for the recommended tire
rotation pattern.
Compact Spare Tire — If Equipped
The compact spare is for temporary emergency
use only. You can identify if your vehicle is
equipped with a compact spare by looking at
the spare tire description on the Tire and
Loading Information Placard located on the
driver’s side door opening or on the sidewall of
the tire. Compact spare tire descriptions begin
with the letter “T” or “S” preceding the size
designation. Example: T145/80D18 103M.
T, S = Temporary Spare Tire
Since this tire has limited tread life, the original
equipment tire should be repaired (or replaced)
and reinstalled on your vehicle at the first
opportunity.
Do not install a wheel cover or attempt to mount
a conventional tire on the compact spare wheel,
since the wheel is designed specifically for the
compact spare tire. Do not install more than
one compact spare tire and wheel on the
vehicle at any given time.
Collapsible Spare Tire — If Equipped
The collapsible spare is for temporary
emergency use only. You can identify if your
vehicle is equipped with a collapsible spare by
looking at the spare tire description on the Tire
and Loading Information Placard located on the
driver’s side door opening or on the sidewall of
the tire.
Collapsible spare tire description example:
165/80-17 101P.
CAUTION!
Because of the reduced ground clearance, do
not take your vehicle through an automatic
car wash with a compact or limited use
temporary spare installed. Damage to the
vehicle may result.
WARNING!
Compact and collapsible spares are for
temporary emergency use only. With these
spares, do not drive more than 50 mph
(80 km/h). Temporary use spares have
limited tread life. When the tread is worn to
the tread wear indicators, the temporary use
spare tire needs to be replaced. Be sure to
follow the warnings, which apply to your
spare. Failure to do so could result in spare
tire failure and loss of vehicle control.
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442SERVICING AND MAINTENANCE
Since this tire has limited tread life, the original
equipment tire should be repaired (or replaced)
and reinstalled on your vehicle at the first
opportunity.
Inflate collapsible tire only after the wheel is
properly installed to the vehicle. Inflate the
collapsible tire using the electric air pump
before lowering the vehicle.
Do not install a wheel cover or attempt to mount
a conventional tire on the collapsible spare
wheel, since the wheel is designed specifically
for the collapsible spare tire.Full Size Spare — If Equipped
The full size spare is for temporary emergency
use only. This tire may look like the originally
equipped tire on the front or rear axle of your
vehicle, but it is not. This spare tire may have
limited tread life. When the tread is worn to the
tread wear indicators, the temporary use full
size spare tire needs to be replaced. Since it is
not the same as your original equipment tire,
replace (or repair) the original equipment tire
and reinstall on the vehicle at the first
opportunity.
Limited Use Spare — If Equipped
The limited use spare tire is for temporary
emergency use only. This tire is identified by a
label located on the limited use spare wheel.
This label contains the driving limitations for
this spare. This tire may look like the original
equipped tire on the front or rear axle of your
vehicle, but it is not. Installation of this limited
use spare tire affects vehicle handling. Since it
is not the same as your original equipment tire,
replace (or repair) the original equipment tire
and reinstall on the vehicle at the first
opportunity.
WHEEL AND WHEEL TRIM CARE
All wheels and wheel trim, especially aluminum
and chrome plated wheels, should be cleaned
regularly using mild (neutral Ph) soap and water
to maintain their luster and to prevent
corrosion. Wash wheels with the same soap
solution recommended for the body of the
vehicle and remember to always wash when the
surfaces are not hot to the touch.
WARNING!
Compact and Collapsible spares are for
temporary emergency use only. With these
spares, do not drive more than 50 mph
(80 km/h). Temporary use spares have
limited tread life. When the tread is worn to
the tread wear indicators, the temporary use
spare tire needs to be replaced. Be sure to
follow the warnings, which apply to your
spare. Failure to do so could result in spare
tire failure and loss of vehicle control.
WARNING!
Limited use spares are for emergency use
only. Installation of this limited use spare tire
affects vehicle handling. With this tire, do not
drive more than the speed listed on the
limited use spare wheel. Keep inflated to the
cold tire inflation pressures listed on your Tire
and Loading Information Placard located on
the driver’s side B-Pillar or the rear edge of
the driver’s side door. Replace (or repair) the
original equipment tire at the first opportunity
and reinstall it on your vehicle. Failure to do
so could result in loss of vehicle control.
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444SERVICING AND MAINTENANCE
(Continued)
2500 Models
Install on rear tires only.
For LT245/70R17E, LT275/70R18E and
LT285/60R20E tires, use of a U-class snow
chain is recommended.
2500 Power Wagon Models
Install on rear tires only.
For a LT285/70R17D tire, use of a U-class
snow chain is recommended.
3500 (Single Rear Wheel) Models
Install on rear tires only.
For LT275/70R18E and LT285/60R20E
tires, use of a U-class snow chain is recom -
mended.
3500 (Dual Rear Wheel) Models
Install on front/rear tires.
For a LT235/80R17E tire, use of a U-class
snow chain is recommended.
TIRE ROTATION RECOMMENDATIONS
Tires on the front and rear axles of vehicles
operate at different loads and perform different
steering, driving, and braking functions. For
these reasons, they wear at unequal rates.
These effects can be reduced by timely rotation
of tires. The benefits of rotation are especially
worthwhile with aggressive tread designs such
as those on all season type tires. Rotation will
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 clear -
ance between tires and other suspension
components, it is important that only trac-
tion devices in good condition are used.
Broken devices can cause serious damage.
Stop the vehicle immediately if noise
occurs that could indicate device breakage.
Remove the damaged parts of the device
before further use.
Install device as tightly as possible and
then retighten after driving about ½ mile
(0.8 km). Autosock traction devices do not
require retightening.
Do not exceed 30 mph (48 km/h).
Drive cautiously and avoid severe turns and
large bumps, especially with a loaded
vehicle.
Do not drive for a prolonged period on dry
pavement.
Observe the traction device manufacturer’s
instructions on the method of installation,
operating speed, and conditions for use.
Always use the suggested operating speed
of the device manufacturer if it is less than
30 mph (48 km/h).
Do not use traction devices on a compact
spare tire.
CAUTION! (Continued)
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446SERVICING AND MAINTENANCE
DEPARTMENT OF TRANSPORTATION
UNIFORM TIRE QUALITY GRADES
The following tire grading categories
were established by the National
Highway Traffic Safety Administration.
The specific grade rating assigned by the
tire's manufacturer in each category is
shown on the sidewall of the tires on
your vehicle.
All passenger vehicle tires must conform
to Federal safety requirements in
addition to these grades.
TREADWEAR
The Treadwear grade is a comparative
rating, based on the wear rate of the tire
when tested under controlled conditions
on a specified government test course.
For example, a tire graded 150 would
wear one and one-half times as well on
the government course as a tire graded
100. The relative performance of tires
depends upon the actual conditions of
their use, however, and may depart
significantly from the norm due to
variations in driving habits, service
practices, and differences in road
characteristics and climate.
TRACTION GRADES
The Traction grades, from highest to
lowest, are AA, A, B, and C. These grades
represent the tire's ability to stop on wet
pavement, as measured under
controlled conditions on specified
government test surfaces of asphalt and
concrete. A tire marked C may have poor
traction performance.
TEMPERATURE GRADES
The Temperature grades are A (the
highest), B, and C, representing the tire's
resistance to the generation of heat and
its ability to dissipate heat, when tested
under controlled conditions on a
specified indoor laboratory test wheel.
Sustained high temperature can cause
the material of the tire to degenerate
and reduce tire life, and excessive
temperature can lead to sudden tire
failure. The grade C corresponds to a
level of performance, which all
passenger vehicle tires must meet
under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A
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 truck. For example, if the spare is used
to replace an outer rear tire it will have to be
remounted on the rim so that the wheel is
dished inward. That way the tread design of
asymmetrical tires and the white writing of
the OWL tires will maintain proper position.
CAUTION! (Continued)WARNING!
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
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498MULTIMEDIA
Air Suspension — If Equipped
After pressing the Air Suspension button on the touchscreen, the following settings will be available: Headlight Off Delay
–+
NOTE:
When the “Headlight Off Delay” feature is selected, the driver can choose to have the headlights remain on for 0, 30, 60, or 90 seconds when exiting
the vehicle.
Setting Name Selectable Options
Auto Entry/Exit — If EquippedOnOff
Easy Exit Seat — If Equipped OnOff
NOTE:
When the “Easy Exit Seat” feature is selected, the Driver’s seat will automatically move rearward once the engine is shut off.
Setting Name Selectable Options
Setting NameSelectable Options
Display Suspension MessagesAllWarnings Only
Tire Jack Mode On Off
NOTE:
When the “Tire Jack Mode” feature is selected, the air suspension system is disabled to assist with changing a spare tire. Transport Mode On Off
NOTE:
When the “Transport Mode” feature is selected, the air suspension system lowers and then disables to assist with flat bed towing.
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