JEEP CHEROKEE 1994 Service Repair Manual

AW-4 VALVE AND SPRING IDENTIFICATION
21 - 330 TRANSMISSION/TRANSFER CASE SPECIFICATIONSJ

AW-4 TORQUE SPECIFICATIONS
NP231/NP242 TORQUE SPECIFICATIONS
JTRANSMISSION/TRANSFER CASE SPECIFICATIONS 21 - 331

WHEELS AND TIRES
CONTENTS
page page
SPECIFICATIONS....................... 11
TIRES................................. 1VEHICLE VIBRATION..................... 9
WHEELS............................... 6
TIRES
INDEX
page page
Cleaning of Tires.......................... 2
General Information........................ 1
Pressure Gauges......................... 2
Repairing Leaks.......................... 3
Replacement Tires........................ 2Rotation................................ 3
Tire Inflation Pressures..................... 2
Tire Noise or Vibration..................... 4
Tire Wear Patterns........................ 4
Tread Wear Indicators...................... 3
GENERAL INFORMATION
Tires are designed for each specific vehicle. They
provide the best overall performance for normal op-
eration. The ride and handling characteristics match
the vehicle's requirements. With proper care they
will give excellent reliability, traction, skid resis-
tance, and tread life. These tires have specific load
carrying capacities. When correctly inflated, they
will operate properly.
Tires used in cool climates, and with light loads
will have a longer life than tires used in hot climates
with heavy loads. Abrasive road surfaces will accel-
erate tire wear.
Driving habits have more effect on tire life than
any other factor. Careful drivers will obtain much
greater mileage than careless drivers.
Driving habits that shorten the life of any tire;
²Rapid acceleration and deceleration
²Severe application of brakes
²High-speed driving
²Taking turns at excessive speeds
²Striking curbs and other obstacles
It is very important to follow the tire rotation in-
terval
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 will have a speed rating letter
after the aspect ratio number. The speed rating isnot always printed on the tire sidewall. The letterS
indicates that the tire is speed rated up to 112 mph.
²Qup to 100 mph
²Tup to 118 mph
²Uup to 124 mph
²Hup to 130 mph
²Vup to 149 mph
²Zmore than 149 mph (consult the tire manufac-
turer for the specific speed rating)
An All Season type tire will have eitherM+S,M
&SorMÐS(indicating mud and snow traction) im-
printed on the side wall.
RADIAL-PLY TIRES
Radial-ply tires improve handling, tread life, 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, but reduced speeds are
recommended.
Radial-ply tires have the same load-carrying capac-
ity as other types of tires of the same size. They use
the same recommended inflation pressures.
SPARE TIRE (TEMPORARY)
The compact spare tire is designed for emergency
use only. The original tire should be repaired and re-
installed at the first opportunity. Refer to Owner's
Manual for complete details.
JWHEELS AND TIRES 22 - 1

TIRE CHAINS
Tire snow chains may be used on certain models.
Refer to Owner's Manual for more information.
CLEANING OF TIRES
Steam cleaning may be used for cleaning.
DO NOT use gasoline or wire brush for cleaning.
DO NOT use mineral oil or an oil-based solvent.
PRESSURE GAUGES
High-quality, dial-type, air-pressure gauges are
recommended. After checking with the gauge, re-
place valve cap and finger tight.
TIRE INFLATION PRESSURES
Under inflation (Fig. 2) causes rapid shoulder wear
and tire flexing.
Over inflation (Fig. 3) causes rapid center wear
and loss of the tire's ability to cushion shocks.
Improper inflation can cause;
²Uneven wear patterns
²Reduced tread life
²Reduced fuel economy
²Unsatisfactory ride
²Cause the vehicle to drift
Refer to the Owner's Manual for information re-
garding proper tire inflation pressure.
This pressure has been carefully selected to provide
for safe vehicle operation. Tire pressure should becheckedcoldonce per month. Tire pressure de-
creases when the outside temperature drops.
Inflation pressures specified on the placards are al-
wayscold inflation pressure. Cold inflation pres-
sure is obtained after the vehicle has not been
operated for at least 3 hours. Tire inflation pressures
may increase from 2 to 6 pounds per square inch
(psi) during operation.Do notreduce this normal
pressure build-up.
Vehicles loaded to the maximum capacity should
not be driven at continuous speeds above 75 mph
(120 km/h).
WARNING: OVER OR UNDER INFLATED TIRES CAN
AFFECT VEHICLE HANDLING AND CAN FAIL SUD-
DENLY, RESULTING IN LOSS OF VEHICLE CON-
TROL.
REPLACEMENT TIRES
OEM tires provide a proper balance of many fea-
tures such as;
²Ride
Fig. 1 Tire Size Identification
Fig. 2 Under Inflation Wear
Fig. 3 Over Inflation Wear
22 - 2 WHEELS AND TIRESJ

²Noise
²Handling
²Durability
²Tread life
²Traction
²Rolling resistance
²Speed capability
Original equipment tires should be used when re-
placement is needed.
Refer to the placard on the vehicle or the
Owner's Manual for the correct replacement
tire.
Failure to use original or equivalent replacement
tires may adversely affect the handling of the vehi-
cle.
The use of oversize tiresis not recommended.
They may cause interference with vehicle suspension
and steering travel. This can cause tire damage or
failure.
WARNING: FAILURE TO EQUIP THE VEHICLE WITH
TIRES HAVING ADEQUATE LOAD CAPABILITY CAN
RESULT IN SUDDEN TIRE FAILURE.
ROTATION
Tires on the front and rear axles operate at differ-
ent loads and perform different steering, driving, and
braking functions. For these reasons, the tires wear
at unequal rates. They may also develop irregular
wear patterns. These effects can be reduced by rotat-
ing the tires according to the maintenance schedule
in the Owners Manual. This will improve tread life,
traction and maintain a smooth quiet ride.
The suggested method of tire rotation is thesame
side front to rearpattern (Fig. 4). Other rotation
methods can be used, but may not provide the same
tire longevity benefits.
TREAD WEAR INDICATORS
Tread wear indicators are molded into the bottom
of the tread grooves. When tread is 1.6 mm (1/16 in.),
the tread wear indicators will appear as a 13 mm
(1/2 in.) band across the tread width.
Tire replacement is necessary when indicators ap-
pear in two or more grooves Fig. 5).
REPAIRING LEAKS
For proper repairing, a radial tire it must be re-
moved from the wheel. Repairs should only be made
if the puncture is in thetread area(Fig. 6). If out-
side the tread area the tire should be replaced.
Deflate tire completely before dismounting 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.
Before mounting tire on wheel, make sure all rust
scale is removed from the rim. Repaint or seal if nec-
essary.
Fig. 4 Tire Rotation Pattern
Fig. 5 Tread Wear Indicators
Fig. 6 Tire Repair Area
JWHEELS AND TIRES 22 - 3

TIRE NOISE OR VIBRATION
The radial-ply tire on your vehicle is more sensi-
tive to improper mounting, or imbalance.
To determine if tires are the cause of vibration,
drive the vehicle over a smooth road at different
speeds. Note the effect of acceleration and decelera-
tion on noise level. Differential and exhaust noise
will change in intensity as speed varies. Tire noise
will usually remain constant.
TIRE WEAR PATTERNS
Under inflation will increase wear on the shoulders
of the tire. Over inflation will increase wear at the
center of the tread.
Excessive camber causes the tire to run at an angle
to the road. One side of tread is worn more than the
other.
Excessive toe-in or toe-out causes wear on the
tread edges. There is a feathered effect across the
tread (Fig. 7).
Fig. 7 Abnormal Tire Tread Wear Patterns
22 - 4 WHEELS AND TIRESJ

LEAD CORRECTION CHART
JWHEELS AND TIRES 22 - 5

WHEELS
GENERAL INFORMATION
Original equipment wheels are designed for the
specified Maximum Vehicle Capacity.
All models use steel or cast aluminum drop center
wheels. The safety rim wheel (Fig. 1) has raised sec-
tions between the rim flanges and the rim well.
Initial inflation of the tire forces the bead over
these raised sections. In case of tire failure, the
raised sections hold the tire in position on the wheel
until the vehicle can be brought to a safe stop.
Cast aluminum wheels require special balance
weights and alignment equipment.
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 en-
larged nose. This enlarged nose is necessary to en-
sure proper retention of the aluminum wheels.
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 han-
dling 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 se-
quence to 129 Nzm (95 ft. lbs.) torque (Fig. 2).Never
use oil or grease on studs or nuts.
WHEEL REPLACEMENT
Wheels must be replaced if they have:
²Excessive runout²Bent or dented
²Leak air through welds
²Have 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:
²Load carrying capacity
²Diameter
²Width
²Offset
²Mounting configuration
Failure to use equivalent replacement wheels may
affect the safety and handling of your vehicle. Re-
placement withusedwheels is not recommended.
Their service history may have included severe treat-
ment.
Refer to the Specifications Chart for informa-
tion regarding above requirements.
WHEEL ORNAMENTATION
WARNING: HANDLE ALL WHEEL ORNAMENTATION
WITH EXTREME CARE DURING REMOVAL AND IN-
STALLATION. SHARP EDGES ON THE COVERS OR
CAPS CAN CAUSE PERSONAL INJURY.
TIRE AND WHEEL BALANCE
It is recommended that a two plane dynamic bal-
ancer be used when a wheel and tire assembly re-
quire balancing. Static should be used only when a
two plane balancer is not available.
For static imbalance, find location of heavy spot
causing imbalance. Counter balance wheel directly
opposite the heavy spot. Determine weight required
to counterbalance the area of imbalance. Place half
of this weight on theinnerrim flange and the other
Fig. 2 Lug Nut Tightening Pattern
Fig. 1 Wheel Safety Rim
22 - 6 WHEELS AND TIRESJ

half on theouterrim flange (Fig. 3, Fig. 4). Off-ve-
hicle balancing is necessary.
Wheel balancing can be accomplished with either
on or off vehicle equipment. When using on-vehicle
balancing equipment, follow these precautions:
²Limited-slip rear axle differential, remove the op-
posite wheel/tire
²Before balancing the wheels/tires on a vehicle
equipped with a transfer case, disconnect the drive
shafts
MATCH MOUNTING
Wheels and tires are match mounted at the factory.
This means that the high spot of the tire is matchedto the low spot on the wheel rim. This technique is
used to reduce run-out in the wheel/tire assembly.
The high spot on the tire is marked with a paint
mark or a bright colored adhesive label on the out-
board sidewall. The low spot on the rim is at the
valve stem location on the wheel rim.
Before dismounting a tire from its wheel, a refer-
ence mark should be placed on the tire at the valve
stem location. This reference will ensure that it is re-
mounted in the original position on the wheel.
(1) Measure the total indicator runout on the cen-
ter of the tire tread rib. Record the indicator reading.
Fig. 3 Static Unbalance & Balance
Fig. 4 Dynamic Unbalance & Balance
JWHEELS AND TIRES 22 - 7