2002 JEEP GRAND CHEROKEE wheel

TRANSFER CASE - NV247
TABLE OF CONTENTS
page page
TRANSFER CASE - NV247
DESCRIPTION........................315
OPERATION..........................316
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV247.......................316
REMOVAL............................317
DISASSEMBLY........................317
CLEANING...........................324
INSPECTION.........................324
ASSEMBLY...........................326
INSTALLATION........................335
SPECIFICATIONS
TRANSFER CASE - NV247.............336
SPECIAL TOOLS
TRANSFER CASE - NV247.............337FLUID
STANDARD PROCEDURE - FLUID DRAIN/
REFILL............................338
FRONT OUTPUT SHAFT SEAL
REMOVAL............................338
INSTALLATION........................338
REAR RETAINER BUSHING AND SEAL
REMOVAL............................339
INSTALLATION........................339
SHIFT CABLE
REMOVAL............................340
INSTALLATION........................340
TRANSFER CASE - NV247
DESCRIPTION
The NV247 (Fig. 1) is an on-demand 4-wheel drive
transfer case with two operating ranges and a neu-
tral position. Operating ranges are 4-high and 4-low.
The 4-low range is used for extra pulling power in
off-road situations.
TRANSFER CASE IDENTIFICATION
A circular I.D. tag is attached to the rear case of
each NV247 transfer case (Fig. 2). The tag indicates
the following information:
²Model number
²Serial number
²Assembly number
²Gear ratio
²Location of manufacture
The transfer case serial number also represents
the date of build.
Fig. 1 NV247 Transfer Case
Fig. 2 Transfer Case I.D. Tag
1 - FILL PLUG
2 - I.D. TAG
3 - DRAIN PLUG
WJTRANSFER CASE - NV247 21 - 315

OPERATION
Under normal driving conditions, the system oper-
ates conventionally, and the majority of available
torque is applied to the rear wheels. However, when
front-to-rear wheel speed variations exist, the pro-
gressive differential transfers torque to the axle with
the better traction, thus minimizing wheel spin and
maximizing control.
The key to this design is a progressive coupling
(Fig. 3), which is supplied with pressurized oil by a
gerotor style pump. The pump rotor and case are
driven by the front and rear driveshafts respectively,
and deliver pressurized oil flow to the coupling in
proportion to their speed difference. The progressive
coupling contains a multi-disc clutch pack that is
alternately splined to the front and rear driveshafts,
and controls torque variation between the front and
rear driveshafts as dictated by the pump.
A set of orifices and valves control the speed-differ-
ential starting point and rate of torque transfer rise
in the clutch. This allows the system to disregard the
normal speed differences between axles that result
from variations in front-to-rear loading and typical
cornering.
Transfer case operating ranges are selected with a
floor mounted shift lever. The shift lever is connectedto the transfer case range lever by an adjustable
cable. Range positions are marked on the shifter
bezel plate.
DIAGNOSIS AND TESTING - TRANSFER CASE - NV247
CONDITION POSSIBLE CAUSE CORRECTION
TRANSFER CASE DIFFICULT TO
SHIFT OR WILL NOT SHIFT INTO
DESIRED RANGE1. Vehicle speed too great to permit
shifting1. Reduce speed to 3-4 km/h (2-3
mph) before attempting to shift
2. Transfer case external shift cable
binding2. Lubricate, repair or replace cable,
or thighten loose components as
necessary
3. Insufficient or incorrect lubricant 3. Drain and refill to edge of fill hole
with correct lubricant
4. Internal components binding,
worn, or damaged4. Disassemble unit and replace
worn or damaged components as
necessary
TRANSFER CASE NOISY IN ALL
MODES1. Insufficient or incorrect lubricant 1. Drain and refill to edge of fill hole
with correct lubricant.If unit is still
noisy after drain and refill,
disassembly and inspection may
be required to locate source of
noise
Fig. 3 Progressive Coupling
21 - 316 TRANSFER CASE - NV247WJ
TRANSFER CASE - NV247 (Continued)

TIRES/WHEELS
TABLE OF CONTENTS
page page
TIRES/WHEELS
DIAGNOSIS AND TESTING - TIRE AND
WHEEL RUNOUT......................1
STANDARD PROCEDURE
STANDARD PROCEDURE - TIRE AND
WHEEL BALANCE......................2
STANDARD PROCEDURE - MATCH
MOUNTING...........................4
STANDARD PROCEDURE - TIRE ROTATION . 5
STANDARD PROCEDURE - WHEEL
INSTALLATION........................5
TIRES
DESCRIPTION
DESCRIPTION - TIRES..................6
DESCRIPTION - RADIAL±PLY TIRES.......6
DESCRIPTION - TIRE INFLATION
PRESSURES..........................6
DESCRIPTION - TIRE PRESSURE FOR
HIGH SPEED..........................7
DESCRIPTION - REPLACEMENT TIRES.....7
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRESSURE
GAUGES.............................8
DIAGNOSIS AND TESTING - TREAD WEAR
INDICATORS..........................8
DIAGNOSIS AND TESTING - TIRE WEAR
PATTERNS...........................8
DIAGNOSIS AND TESTING - TIRE NOISE
OR VIBRATION........................8STANDARD PROCEDURE - REPAIRING
LEAKS...............................8
CLEANING.............................9
SPECIFICATIONS
TIRES...............................9
SPECIFICATIONS -.....................9
SPARE TIRE
DESCRIPTION - SPARE / TEMPORARY TIRE . . 10
WHEELS
DESCRIPTION.........................10
DIAGNOSIS AND TESTING - WHEEL
INSPECTION.........................10
STANDARD PROCEDURE - WHEEL
REPLACEMENT.......................10
SPECIFICATIONS
TORQUE CHART......................11
STUDS
REMOVAL.............................11
INSTALLATION.........................11
TIRE PRESSURE MONITORING
DESCRIPTION.........................12
OPERATION...........................12
DIAGNOSIS AND TESTING - TIRE PRESSURE
MONITORING SYSTEM.................12
SENSOR
REMOVAL - TIRE PRESSURE SENSOR/
TRANSMITTER.......................12
INSTALLATION - TIRE PRESSURE SENSOR/
TRANSMITTER.......................13
TIRES/WHEELS
DIAGNOSIS AND TESTING - TIRE AND WHEEL
RUNOUT
Radial runout is the difference between the high
and low points on the tire or wheel (Fig. 1).
Lateral runout is thewobbleof the tire or wheel.
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.
METHOD 2 (RELOCATE TIRE ON WHEEL)
NOTE: Rotating the tire on wheel is particularly
effective when there is runout in both tire and
wheel.
WJTIRES/WHEELS 22 - 1

(1) Remove tire from wheel and mount wheel on
service dynamic balance machine.
(2) Check wheel radial runout (Fig. 2) and lateral
runout (Fig. 3).
²STEEL WHEELS: Radial runout 0.040 in., Lat-
eral runout 0.045 in. (maximum)
²ALUMINUM 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 22 - TIRES/WHEELS -
STANDARD PROCEDURE) .
STANDARD PROCEDURE
STANDARD PROCEDURE - 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 opera-
tion instructions for proper cone mounting proce-
dures. 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.
NOTE: Cast aluminum and forged aluminum wheels
require coated balance weights and special align-
ment equipment.
Wheel balancing can be accomplished with either
on or off vehicle equipment. When using on-vehiclebalancing equipment, remove the opposite wheel/tire.
Off-vehicle balancing is recommended.
For static balancing, find the location of the heavy
spot causing the imbalance. Counter balance wheel
directly opposite the heavy spot. Determine weight
Fig. 1 Checking Tire/Wheel/Hub Runout
1 - RADIAL RUNOUT
2 - LATERAL RUNOUT
Fig. 2 Radial Runout
1 - MOUNTING CONE
2 - SPINDLE SHAFT
3 - WING NUT
4 - PLASTIC CUP
5 - DIAL INDICATOR
6 - WHEEL
7 - DIAL INDICATOR
Fig. 3 Lateral Runout
1 - MOUNTING CONE
2 - SPINDLE SHAFT
3 - WING NUT
4 - PLASTIC CUP
5 - DIAL INDICATOR
6 - WHEEL
7 - DIAL INDICATOR
22 - 2 TIRES/WHEELSWJ
TIRES/WHEELS (Continued)

required to counter balance the area of imbalance.
Place half of this weight on theinnerrim flange and
the other half on theouterrim flange (Fig. 4).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. 5).
Fig. 4 Static Unbalance & Balance
1 - HEAVY SPOT
2 - CENTER LINE OF SPINDLE
3 - ADD BALANCE WEIGHTS HERE4 - CORRECTIVE WEIGHT LOCATION
5 - TIRE OR WHEEL TRAMP, OR WHEEL HOP
Fig. 5 Dynamic Unbalance & Balance
1 - CENTER LINE OF SPINDLE
2 - ADD BALANCE WEIGHTS HERE3 - CORRECTIVE WEIGHT LOCATION
4 - HEAVY SPOT WHEEL SHIMMY AND VIBRATION
WJTIRES/WHEELS 22 - 3
TIRES/WHEELS (Continued)

STANDARD PROCEDURE - MATCH MOUNTING
Tires and wheels are currently not 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 adhe-
sive 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.
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
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. 6). Record the
indicator reading and mark the high spot on the tire.
Place a mark on the tire at the valve stem location
(Fig. 7).
(2) Break down the tire and remount it 180
degrees on the rim (Fig. 8).
(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 22 - TIRES/WHEELS -
DIAGNOSIS AND TESTING).
(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. 9). This procedure will normally reduce the
runout to an acceptable amount.
Fig. 6 Dial Indicator
Fig. 7 First Measurement On Tire
1 - REFERENCE MARK
2 - 1ST MEASUREMENT
HIGH SPOT MARK TIRE AND RIM
3 - WHEEL
4 - VALVE STEM
Fig. 8 Remount Tire 180 Degrees
1 - VALVE STEM
2 - REFERENCE MARK
22 - 4 TIRES/WHEELSWJ
TIRES/WHEELS (Continued)

STANDARD PROCEDURE - TIRE 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
patterns. These effects can be reduced by rotating
the tires at regular intervals. The benefits of tire
rotation are:
²Increase tread life
²Maintain traction levels
²A smooth, quiet ride
The suggested method of tire rotation is (Fig. 10).
Other rotation methods can be used, but they will
not provide all the tire longevity benefits.
STANDARD PROCEDURE - 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.
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
sequence to the proper torque specification (Fig. 11).
Never use oil or grease on studs or nuts.
Fig. 9 Remount Tire 90 Degrees In Direction of
Arrow
1 - 2ND HIGH SPOT ON TIRE
2 - 1ST HIGH SPOT ON TIRE
Fig. 10 Tire Rotation Pattern
Fig. 11 LUG NUT TIGHTENING PATTERN - TYPICAL
WJTIRES/WHEELS 22 - 5
TIRES/WHEELS (Continued)

TIRES
DESCRIPTION
DESCRIPTION - TIRES
Tires are designed and engineered for each specific
vehicle. They provide the best overall performance
for normal operation. The ride and handling charac-
teristics match the vehicle's requirements. With
proper care they will give excellent reliability, trac-
tion, 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 care-
less drivers. A few of the driving habits which will
shorten the life of any tire are:
²Rapid acceleration
²Severe brake applications
²High speed driving
²Excessive speeds on turns
²Striking curbs and other obstacles
Radial-ply tires are more prone to irregular tread
wear. It is important to follow the tire rotation inter-
val shown in the section on Tire Rotation.(Refer to 22
- TIRES/WHEELS - STANDARD PROCEDURE),
This will help to achieve a greater tread life.
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. 12).
Performance tires have a speed rating letter after
the aspect ratio number. The speed rating is not
always printed on the tire sidewall. These ratings
are:
²Qup to 100 mph
²Sup to 112 mph
²Tup to 118 mph
²Uup to 124 mph
²Hup to 130 mph
²Vup to 149 mph
²Zmore than 149 mph (consult the tire manu-
facturer for the specific speed rating)
An All Season type tire will have eitherM+S,M
&SorM±S(indicating mud and snow traction)
imprinted on the side wall.
TIRE CHAINS
Tire snow chains may be used oncertainmodels.
Refer to the Owner's Manual for more information.
DESCRIPTION - RADIAL±PLY TIRES
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 capac-
ity 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 fail-
ure. 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.
DESCRIPTION - TIRE INFLATION PRESSURES
Under inflation will cause rapid shoulder wear, tire
flexing, and possible tire failure (Fig. 13).
Over inflation will cause rapid center wear and
loss of the tire's ability to cushion shocks (Fig. 14).
Improper inflation can cause:
²Uneven wear patterns
²Reduced tread life
²Reduced fuel economy
Fig. 12 Tire Identification
22 - 6 TIRES/WHEELSWJ