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XJ TIRES AND WHEELS 22 - 1
TIRES AND WHEELS
TABLE OF CONTENTS
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TIRES ................................... 1 WHEELS ................................. 7
TIRES
TABLE OF CONTENTS
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DESCRIPTION AND OPERATION
TIRES ..................................1
RADIAL-PLY TIRES ........................2
SPARE TIRE–TEMPORARY ..................2
TIRE INFLATION PRESSURES ...............2
TIRE PRESSURE FOR HIGH SPEED...........3
REPLACEMENT TIRES .....................3
DIAGNOSIS AND TESTING
PRESSURE GAUGES ......................3
TREAD WEAR INDICATORS .................3
DESCRIPTION AND OPERATION
TIRES
DESCRIPTION
Tires are designed and engineered for each specific
vehicle. They provide the best overall performance
for normal operation. The ride and handling characteristics match the vehicle’s requirements. With
proper care they will give excellent reliability, traction, skid resistance, and tread life.
Driving habits have more effect on tire life than
any other factor. Careful drivers will obtain in most
cases, much greater mileage than severe use or careless drivers. A few of the driving habits which will
shorten the life of any tire are:
• Rapid acceleration
• Severe brake applications
• High speed driving
• Excessive speeds on turns
• Striking curbs and other obstacles
Radial-ply tires are more prone to irregular tread
wear. It is important to follow the tire rotation interval shown in the section on Tire Rotation. This will
help to achieve a greater tread life.
TIRE WEAR PATTERNS.....................3
TIRE NOISE OR VIBRATION .................3
SERVICE PROCEDURES
ROTATION...............................4
MATCH MOUNTING........................4
REPAIRING LEAKS ........................5
CLEANING AND INSPECTION
CLEANING TIRES .........................6
SPECIFICATIONS
TIRE SIZE ...............................6
TIRE IDENTIFICATION
Tire type, size, aspect ratio and speed rating are
encoded in the letters and numbers imprinted on the
side wall of the tire. Refer to the chart to decipher
the tire identification code (Fig. 1).
Performance tires have a speed rating letter after
the aspect ratio number.
LETTER SPEED RATING
S 180 km/h (112 mph)
T 190 km/h (118 mph)
U 200 km/h (124 mph)
H 210 km/h (130 mph)
V 240 km/h (149 mph)
W 270 km/h (168 mph)
Y 300 km/h (186 mph)
The speed rating is not always printed on the tire
sidewall.
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22 - 2 TIRES AND WHEELS XJ
DESCRIPTION AND OPERATION (Continued)
SPARE TIRE–TEMPORARY
DESCRIPTION
The temporary spare tire is designed for emergency use only. The original tire should be repaired
or replaced at the first opportunity, then reinstalled.
Do not exceed speeds of 50 M. P. H. when using the
temporary spare tire. Refer to Owner’s Manual for
complete details.
TIRE INFLATION PRESSURES
Under inflation will cause rapid shoulder wear, tire
flexing, and possible tire failure (Fig. 2).
Fig. 1 Tire Identification
TIRE CHAINS
Tire snow chains may be used on certain models.
Refer to the Owner’s Manual for more information.
RADIAL-PLY TIRES
DESCRIPTION
Radial-ply tires improve handling, tread life and
ride quality, and decrease rolling resistance.
Radial-ply tires must always be used in sets of
four. Under no circumstances should they be used on
the front only. They may be mixed with temporary
spare tires when necessary. A maximum speed of 50
MPH is recommended while a temporary spare is in
use.
Radial-ply tires have the same load-carrying capacity as other types of tires of the same size. They also
use the same recommended inflation pressures.
The use of oversized tires, either in the front or
rear of the vehicle, can cause vehicle drive train failure. This could also cause inaccurate wheel speed
signals when the vehicle is equipped with Anti-Lock
Brakes.
The use of tires from different manufactures on the
same vehicle is NOT recommended. The proper tire
pressure should be maintained on all four tires.
Fig. 2 Under Inflation Wear
1 – THIN TIRE THREAD AREAS
Over inflation will cause rapid center wear and
loss of the tire’s ability to cushion shocks (Fig. 3).
Fig. 3 Over Inflation Wear
1 – THIN TIRE THREAD AREA
Improper inflation can cause:
• Uneven wear patterns
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XJ TIRES AND WHEELS 22 - 3
DESCRIPTION AND OPERATION (Continued)
• Reduced tread life
• Reduced fuel economy
• Unsatisfactory ride
• Vehicle drift
For proper tire pressure specification refer to the
Tire Inflation Pressure Chart provided with the vehicle.
Tire pressures have been chosen to provide safe
operation, vehicle stability, and a smooth ride. Tire
pressure should be checked cold once a month. The
spare tire pressure should be check at least twice
annually. Tire pressure decreases as the ambient
temperature drops. Check tire pressure frequently
when ambient temperature varies widely.
Inflation pressures specified on the placards are
cold inflation pressure. The vehicle must sit for at
least 3 hours to obtain the correct cold inflation pressure reading. Or driven less than one mile after sitting for 3 hours. Tire inflation pressures may
increase from 2 to 6 pounds per square inch (psi)
during operation, due to increased tire temperature.
WARNING: OVER OR UNDER INFLATED TIRES
CAN AFFECT VEHICLE HANDLING AND TREAD
WEAR. THIS MAY CAUSE THE TIRE TO FAIL SUDDENLY, RESULTING IN LOSS OF VEHICLE CONTROL.
TIRE PRESSURE FOR HIGH SPEED
DESCRIPTION
Where speed limits allow the vehicle to be driven
at high speeds, correct tire inflation pressure is very
important. For speeds up to and including 120 km/h
(75 mph), tires must be inflated to the pressures
shown on the tire placard. For continuous speeds in
excess of 120 km/h (75 mph), tires must be inflated
to the maximum pressure specified on the tire sidewall.
Vehicles loaded to the maximum capacity should
not be driven at continuous speeds above 75 mph
(120 km/h).
For emergency vehicles that are driven at speeds
over 90 mph (144 km/h), special high speed tires
must be used. Consult tire manufacturer for correct
inflation pressure recommendations.
REPLACEMENT TIRES
• Handling
• Durability
• Tread life
• Traction
• Rolling resistance
• Speed capability
It is recommended that tires equivalent to the original equipment tires be used when replacement is
needed.
Failure to use equivalent replacement tires may
adversely affect the safety and handling of the vehicle.
The use of oversize tires may cause interference
with vehicle components. Under extremes of suspension and steering travel, interference with vehicle
components may cause tire damage.
WARNING: FAILURE TO EQUIP THE VEHICLE WITH
TIRES HAVING ADEQUATE SPEED CAPABILITY
CAN RESULT IN SUDDEN TIRE FAILURE.
DIAGNOSIS AND TESTING
PRESSURE GAUGES
A quality air pressure gauge is recommended to
check tire pressure. After checking the air pressure,
replace valve cap finger tight.
TREAD WEAR INDICATORS
Tread wear indicators are molded into the bottom
of the tread grooves. When tread depth is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band (Fig. 4).
Tire replacement is necessary when indicators
appear in two or more grooves or if localized balding
occurs.
TIRE WEAR PATTERNS
Under inflation will cause wear on the shoulders of
tire. Over inflation will cause wear at the center of
tire.
Excessive camber causes the tire to run at an
angle to the road. One side of tread is then worn
more than the other (Fig. 5).
Excessive toe-in or toe-out causes wear on the
tread edges and a feathered effect across the tread
(Fig. 5).
DESCRIPTION
The original equipment tires provide a proper bal-
ance of many characteristics such as:
• Ride
• Noise
TIRE NOISE OR VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, vibration, wheel
defects, or possibly tire imbalance.
To find out if tires are causing the noise or vibration, drive the vehicle over a smooth road at varying
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22 - 4 TIRES AND WHEELS XJ
DIAGNOSIS AND TESTING (Continued)
patterns. These effects can be reduced by rotating
the tires at regular intervals. The benefits of tire
rotation are:
• Increase tread life
• Maintain traction levels
• A smooth, quiet ride
The suggested method of tire rotation is (Fig. 6).
Other rotation methods can be used, but they will
not provide all the tire longevity benefits.
Fig. 4 Tread Wear Indicators
1 – THREAD ACCEPTABLE
2 – THREAD UNACCEPTABLE
3 – WEAR INDICATOR
Fig. 6 Tire Rotation Pattern
MATCH MOUNTING
speeds. Note the noise level during acceleration,
deceleration and slight left and right steering inputs.
SERVICE PROCEDURES
ROTATION
Tires on the front and rear operate at different
loads and perform different steering, driving, and
braking functions. For these reasons they wear at
unequal rates and tend to develop irregular wear
Tires and wheels are currently match mounted at
the factory. Match mounting is a technique used to
reduce runout in the wheel/tire assembly. This means
that the high spot of the tire is aligned with the low
spot on the wheel rim. The high spot on the tire is
marked with a paint mark or a bright colored adhesive label on the outboard sidewall. The low spot on
the rim is identified with a label on the outside of the
rim and a dot on the inside of the rim. If the outside
label has been removed the tire will have to be
removed to locate the dot on the inside of the rim.
Fig. 5 Tire Wear Patterns
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XJ TIRES AND WHEELS 22 - 5
SERVICE PROCEDURES (Continued)
Before dismounting a tire from its wheel, a reference mark should be placed on the tire at the valve
stem location. This reference will ensure that it is
remounted in the original position on the wheel.
(1) Use a dial indicator to locate the high spot of
the tire on the center tread rib (Fig. 7). Record the
indicator reading and mark the high spot on the tire.
Place a mark on the tire at the valve stem location
(Fig. 8).
Fig. 7 Dial Indicator
(2) Break down the tire and remount it 180
degrees on the rim (Fig. 9).
Fig. 9 Remount Tire 180 Degrees
1 – VALVE STEM
2 – REFERENCE MARK
Fig. 8 First Measurement On Tire
1 – REFERENCE MARK
2 – 1ST MEASUREMENT
HIGH SPOT MARK TIRE AND RIM
3 – WHEEL
4 – VALVE STEM
(3) Measure the total runout again and mark the
tire to indicate the high spot.
(4) If runout is still excessive use the following
procedures.
(a) If the high spot is within 101.6 mm (4.0 in.)
of the first spot and is still excessive, replace the
tire.
(b) If the high spot is within 101.6 mm (4.0 in.)
of the first spot on the wheel, the wheel may be out
of specifications. Refer to Wheel and Tire Runout.
(c) If the high spot is NOT within 101.6 mm (4.0
in.) of either high spot, draw an arrow on the tread
from second high spot to first. Break down the tire
and remount it 90 degrees on rim in that direction
(Fig. 10). This procedure will normally reduce the
runout to an acceptable amount.
REPAIRING LEAKS
For proper repairing, a radial tire must be removed
from the wheel. Repairs should only be made if the
defect, or puncture, is in the tread area (Fig. 11). The
tire should be replaced if the puncture is located in
the sidewall.
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22 - 6 TIRES AND WHEELS XJ
SERVICE PROCEDURES (Continued)
Fig. 11 Tire Repair Area
Fig. 10 Remount Tire 90 Degrees In Direction of
Arrow
1 – 2ND HIGH SPOT ON TIRE
2 – 1ST HIGH SPOT ON TIRE
Deflate tire completely before removing the tire
from the wheel. Use lubrication such as a mild soap
solution when dismounting or mounting tire. Use
tools free of burrs or sharp edges which could damage the tire or wheel rim.
Before mounting tire on wheel, make sure all rust
is removed from the rim bead and repaint if necessary.
Install wheel on vehicle, and tighten to proper
torque specification.
1 – REPAIRABLE AREA
To remove the protective coating, apply warm
water and let it soak for a few minutes. Afterwards,
scrub the coating away with a soft bristle brush.
Steam cleaning may also be used to remove the coating.
NOTE: DO NOT use gasoline, mineral oil, oil-based
solvent or a wire brush for cleaning.
SPECIFICATIONS
TIRE SIZE
CLEANING AND INSPECTION
CLEANING TIRES
Remove the protective coating on the tires before
delivery of a vehicle. This coating may cause deterioration of the tires.
TIRE SIZE SUPPLIER
P215/75R15 Goodyear
P225/75R15 Goodyear
P225/70R15 Goodyear
P225/70R16 Goodyear
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XJ TIRES AND WHEELS 22 - 7
WHEELS
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
WHEEL .................................7
DIAGNOSIS AND TESTING
WHEEL INSPECTION.......................7
TIRE AND WHEEL RUNOUT .................7
DESCRIPTION AND OPERATION
WHEEL
DESCRIPTION
The rim size is on the vehicle safety certification
label located on the drivers door shut face. The size
of the rim is determined by the drivetrain package.
Original equipment wheels/rims are designed for
operation up to the specified maximum vehicle capacity.
All models use stamped steel, cast aluminum or
forged aluminum wheels. Every wheel has raised sections between the rim flanges and rim drop well
called safety humps (Fig. 1).
SERVICE PROCEDURES
WHEEL INSTALLATION .....................8
TIRE AND WHEEL BALANCE.................9
SPECIFICATIONS
TORQUE CHART .........................11
sure, the raised sections help hold the tire on the
wheel.
The wheel studs and nuts are designed for specific
applications. All aluminum and some steel wheels
have wheel stud nuts with an enlarged nose. This
enlarged nose is necessary to ensure proper retention
of the wheels. Do not use replacement studs or nuts
with a different design or lesser quality.
DIAGNOSIS AND TESTING
WHEEL INSPECTION
Inspect wheels for:
• Excessive run out
• Dents or cracks
• Damaged wheel lug nut holes
• Air Leaks from any area or surface of the rim
Fig. 1 Safety Rim
1 – FLANGE
2 – RIDGE
3 – WELL
Initial inflation of the tire forces the bead over
these raised sections. In case of rapid loss of air pres-
NOTE: Do not attempt to repair a wheel by hammering, heating or welding.
If a wheel is damaged an original equipment
replacement wheel should be used. When obtaining
replacement wheels, they should be equivalent in
load carrying capacity. The diameter, width, offset,
pilot hole and bolt circle of the wheel should be the
same as the original wheel.
WARNING: FAILURE TO USE EQUIVALENT
REPLACEMENT WHEELS MAY ADVERSELY AFFECT
THE SAFETY AND HANDLING OF THE VEHICLE.
USED WHEELS ARE NOT RECOMMENDED. THE
SERVICE HISTORY OF THE WHEEL MAY HAVE
INCLUDED SEVERE TREATMENT OR VERY HIGH
MILEAGE. THE RIM COULD FAIL WITHOUT WARNING.
TIRE AND WHEEL RUNOUT
Radial runout is the difference between the high
and low points on the tire or wheel (Fig. 2).
Lateral runout is the wobble of the tire or wheel.
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22 - 8 TIRES AND WHEELS XJ
DIAGNOSIS AND TESTING (Continued)
• STEEL WHEELS: Radial runout 0.040 in., Lat-
eral runout 0.045 in. (maximum)
• ALUMINUM WHEELS: Radial runout 0.030 in.,
Lateral runout 0.035 in. (maximum)
(3) If point of greatest wheel lateral runout is near
original chalk mark, remount tire 180 degrees.
Recheck runout, Refer to match mounting procedure.
Fig. 2 Checking Tire/Wheel/Hub Runout
1 – RADIAL RUNOUT
2 – LATERAL RUNOUT
Radial runout of more than 1.5 mm (.060 inch)
measured at the center line of the tread may cause
the vehicle to shake.
Lateral runout of more than 2.0 mm (.080 inch)
measured near the shoulder of the tire may cause the
vehicle to shake.
Sometimes radial runout can be reduced. Relocate
the wheel and tire assembly on the mounting studs
(See Method 1). If this does not reduce runout to an
acceptable level, the tire can be rotated on the wheel.
(See Method 2).
METHOD 1 (RELOCATE WHEEL ON HUB)
(1) Drive vehicle a short distance to eliminate tire
flat spotting from a parked position.
(2) Check wheel bearings and adjust if adjustable
or replace if necessary.
(3) Check the wheel mounting surface.
(4) Relocate wheel on the mounting, two studs
over from the original position.
(5) Tighten wheel nuts until all are properly
torqued, to eliminate brake distortion.
(6) Check radial runout. If still excessive, mark
tire sidewall, wheel, and stud at point of maximum
runout and proceed to Method 2.
Fig. 3 Radial Runout
1 – MOUNTING CONE
2 – SPINDLE SHAFT
3 – WING NUT
4 – PLASTIC CUP
5 – DIAL INDICATOR
6 – WHEEL
7 – DIAL INDICATOR
SERVICE PROCEDURES
WHEEL INSTALLATION
The wheel studs and nuts are designed for specific
applications. They must be replaced with equivalent
parts. Do not use replacement parts of lesser quality
or a substitute design. All aluminum and some steel
wheels have wheel stud nuts which feature an
enlarged nose. This enlarged nose is necessary to
ensure proper retention of the aluminum wheels.
NOTE: Do not use chrome plated lug nuts with
chrome plated wheels.
METHOD 2 (RELOCATE TIRE ON WHEEL)
NOTE: Rotating the tire on wheel is particularly
effective when there is runout in both tire and
wheel.
(1) Remove tire from wheel and mount wheel on
service dynamic balance machine.
(2) Check wheel radial runout (Fig. 3) and lateral
runout (Fig. 4).
Before installing the wheel, be sure to remove any
build up of corrosion on the wheel mounting surfaces.
Ensure wheels are installed with good metal-to-metal
contact. Improper installation could cause loosening
of wheel nuts. This could affect the safety and handling of your vehicle.
To install the wheel, first position it properly on
the mounting surface. All wheel nuts should then be
tightened just snug. Gradually tighten them in
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XJ TIRES AND WHEELS 22 - 9
SERVICE PROCEDURES (Continued)
• Leak air through welds
• Have damaged bolt holes
Wheel repairs employing hammering, heating, or
welding are not allowed.
Original equipment wheels are available through
your dealer. Replacement wheels from any other
source should be equivalent in:
• Load carrying capacity
• Diameter
• Width
• Offset
• Mounting configuration
Failure to use equivalent replacement wheels may
affect the safety and handling of your vehicle.
Replacement with used wheels is not recommended.
Their service history may have included severe treatment.
Fig. 4 Lateral Runout
1 – MOUNTING CONE
2 – SPINDLE SHAFT
3 – WING NUT
4 – PLASTIC CUP
5 – DIAL INDICATOR
6 – WHEEL
7 – DIAL INDICATOR
sequence to the proper torque specification (Fig. 5).
Never use oil or grease on studs or nuts.
TIRE AND WHEEL BALANCE
It is recommended that a two plane service
dynamic balancer be used when a tire and wheel
assembly require balancing. Refer to balancer operation instructions for proper cone mounting procedures. Typically use front cone mounting method for
steel wheels. For aluminum wheel use back cone
mounting method without cone spring.
NOTE: Static should be used only when a two
plane balancer is not available.
Fig. 5 Lug Nut Tightening Pattern
WHEEL REPLACEMENT
Wheels must be replaced if they have:
• Excessive runout
• Bent or dented
NOTE: Cast aluminum and forged aluminum wheels
require coated balance weights and special alignment equipment.
Wheel balancing can be accomplished with either
on or off vehicle equipment. When using on-vehicle
balancing equipment, remove the opposite wheel/tire.
Off-vehicle balancing is recommended.
For static balancing, find location of heavy spot
causing the imbalance. Counter balance wheel
directly opposite the heavy spot. Determine weight
required to counter balance the area of imbalance.
Place half of this weight on the inner rim flange and
the other half on the outer rim flange (Fig. 6).
For dynamic balancing, the balancing equipment is
designed to locate the amount of weight to be applied
to both the inner and outer rim flange (Fig. 7).
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22 - 10 TIRES AND WHEELS XJ
SERVICE PROCEDURES (Continued)
Fig. 6 Static Unbalance & Balance
1 – HEAVY SPOT
2 – CENTER LINE OF SPINDLE
3 – ADD BALANCE WEIGHTS HERE
4 – CORRECTIVE WEIGHT LOCATION
5 – TIRE OR WHEEL TRAMP, OR WHEEL HOP
1 – CENTER LINE OF SPINDLE
2 – ADD BALANCE WEIGHTS HERE
Fig. 7 Dynamic Unbalance & Balance
3 – CORRECTIVE WEIGHT LOCATION
4 – HEAVY SPOT WHEEL SHIMMY AND VIBRATION
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XJ TIRES AND WHEELS 22 - 11
SPECIFICATIONS
TORQUE CHART
DESCRIPTION TORQUE
Lug Nut
1/2 X 20 with 60° Cone .......... 115-150 N·m
(85-115 ft. lbs.)
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