396 IN CASE OF EMERGENCY
Dual Rear Wheels
Slots in the wheels will assist in properly orienting the inner
and outer wheels. Align these slots when assembling 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 correctly
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 loca-
tion. The correct direction of rotation for dual tire installa -
tions must also be observed
It is recommended that wheel stud nuts be kept torqued to
specifications at all times. Torque wheel stud nuts to specifi -
cations at each lubrication interval.
Refer to “Wheel And Tire Torque Specifications” in “Tech -
nical Specifications” for further information. Wheel Nuts
All wheel nuts should be tightened occasionally to eliminate
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
wheel nuts should first be firmly seated against the wheel.
The wheel nuts should then be tightened to recommended
torque. Tighten the wheel nuts to final torque in increments.
Progress around the bolt circle, tightening the wheel nut
opposite to the wheel nut just previously tightened until
final torque is achieved.
Refer to “Wheel And Tire Torque Specifications” in “Tech
-
nical Specifications” for further information.
To Stow The Flat Or Spare — If Equipped
Refer to Upfitters Body Builder’s Guide for information on
stowing your spare tire (if equipped).
SERVICING AND MAINTENANCE 445
Tire Markings
Tire Markings
NOTE:
• P (Passenger) — Metric tire sizing is based on U.S. designstandards. P-Metric tires have the letter “P” molded into
the sidewall preceding the size designation. Example:
P215/65R15 95H.
• European — Metric tire sizing is based on European design standards. Tires designed to this standard have the
tire size molded into the sidewall beginning with the
section width. The letter "P" is absent from this tire size
designation. Example: 215/65R15 96H.
• LT (Light Truck) — Metric tire sizing is based on U.S. design standards. The size designation for LT-Metric tires
is the same as for P-Metric tires except for the letters “LT”
that are molded into the sidewall preceding the size desig -
nation. Example: LT235/85R16.
• Temporary spare tires are designed for temporary emer -
gency use only. Temporary high pressure compact spare
tires have the letter “T” or “S” molded into the sidewall
preceding the size designation. Example: T145/80D18
103M.
• High flotation tire sizing is based on U.S. design standards and it begins with the tire diameter molded into the side -
wall. Example: 31x10.5 R15 LT.
1 — U.S. DOT Safety
Standards Code (TIN) 4 — Maximum Load
2 — Size Designation 5 — Maximum Pressure
3 — Service Description 6 — Treadwear, Traction and Temperature Grades
7
446 SERVICING AND MAINTENANCE
Tire Sizing Chart EXAMPLE:
Example Size Designation: P215/65R15XL 95H, 215/65R15 96H, LT235/85R16C, T145/80D18 103M, 31x10.5 R15 LT
P = Passenger car tire size based on U.S. design standards, or
"....blank...." = Passenger car tire based on European design standards, or
LT = Light truck tire based on U.S. design standards, or
T or S = Temporary spare tire or
31 = Overall diameter in inches (in)
215, 235, 145 = Section width in millimeters (mm)
65, 85, 80 = Aspect ratio in percent (%)
• Ratio of section height to section width of tire, or
10.5 = Section width in inches (in)
R = Construction code
• "R" means radial construction, or
• "D" means diagonal or bias construction
15, 16, 18 = Rim diameter in inches (in)
Service Description:
95 = Load Index
• A numerical code associated with the maximum load a tire can carry
450 SERVICING AND MAINTENANCE
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 recom-
mended pressure for your vehicle.
Example Tire Placard Location (Door) Example Tire Placard Location (B-Pillar)
SERVICING AND MAINTENANCE 451
Tire And Loading Information PlacardTire 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 pres
-
sures 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 occu-
pants 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 refer -
enced here.
7
458 SERVICING AND MAINTENANCE
Tread Wear Indicators
Tread wear indicators are in the original equipment tires to
help you in determining when your tires should be replaced.Tire Tread
These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes a 1/16 of an inch (1.6 mm). When the tread is worn
to the tread wear indicators, the tire should be replaced. Refer to “Replacement Tires” in this section for further infor
-
mation.
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. Rota -
tion of these tires per the vehicle scheduled maintenance is
highly recommended.
1 — Worn Tire
2 — New Tire
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.
SERVICING AND MAINTENANCE 461
Snow Tires
Some areas of the country require the use of snow tires
during the Winter. Snow tires can be identified by a “moun-
tain/snowflake” symbol on the tire sidewall.
If you need snow tires, select tires equivalent in size
and type to the original equipment tires. Use snow
tires only in sets of four; failure to do so may
adversely affect the safety and handling of your vehicle.
Snow tires generally have lower speed ratings than what was
originally equipped with your vehicle and should not be
operated at sustained speeds over 75 mph (120 km/h). For speeds above 75 mph (120 km/h) refer to original equipment
or an authorized tire dealer for recommended safe operating
speeds, loading and cold tire inflation pressures.
While studded tires improve performance on ice, skid and
traction capability on wet or dry surfaces may be poorer than
that of non-studded tires. Some states prohibit studded tires;
therefore, local laws should be checked before using these
tire types.Spare Tires — If Equipped
NOTE:
For vehicles equipped with Tire Service Kit instead of a spare
tire, please refer to “Tire Service Kit” in “In Case Of Emer -
gency” for further information.
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.
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.
7
462 SERVICING AND MAINTENANCE
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 conven-
tional 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 collaps
-
ible 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.
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.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.