clutch JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

(10) Install differential snap-ring (Fig. 74).
(11) Install intermediate clutch shaft (Fig. 75).
(12) Install clutch shaft thrust washer (Fig. 76).
(13) Install clutch shaft snap-ring (Fig. 77).(14) Inspect mode fork assembly (Fig. 78). Replace
pads and bushing if necessary. Replace fork tube if
bushings inside tube are worn or damaged. Also
check springs and slider bracket (Fig. 78). Replace
worn, damaged components.
Fig. 74 Installing Differential Snap-Ring
1 - DIFFERENTIAL SNAP-RING
Fig. 75 Installing Intermediate Clutch Shaft
1 - INTERMEDIATE CLUTCH SHAFT
Fig. 76 Installing Clutch Shaft Thrust Washer
1 - CLUTCH SHAFT THRUST RING
Fig. 77 Installing Clutch Shaft Snap-Ring
1 - SNAP-RING
2 - INTERMEDIATE CLUTCH SHAFT
21 - 302 TRANSFER CASE - NV242WJ
TRANSFER CASE - NV242 (Continued)

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)

FRONT OUTPUT SHAFT AND DRIVE CHAIN
(1) Remove oil pickup tube from rear case (Fig.
17).
(2) Remove drive gear snap-ring (Fig. 18).
(3) Disengage drive gear (Fig. 18). Pry gear
upward and off mainshaft as shown.
(4) Remove front output shaft, drive chain and
drive gear as assembly (Fig. 18).
(5) Remove output shaft drive gear snap ring.
(6) Remove output shaft drive gear from output
shaft.
SHIFT FORKS AND MAINSHAFT
(1) Remove detent plug, O-ring, detent spring and
detent plunger (Fig. 19).
(2) Remove shift rail from shift fork and transfer
case housing.
(3) Rotate range shift fork until it disengages from
shift sector.
(4) Remove mainshaft and shift fork from input
gear pilot bearing.
NOTE: Loose needle bearings are used to support
the drive sprocket hub on the mainshaft. Do not lift
mainshaft by drive sprocket hub or needle bearings
will become dislodged.
(5) Wrap rag around mainshaft underneath drive
sprocket hub and remove drive sprocket hub from
mainshaft. Be sure to retrieve all the drive sprocket
hub needle bearings.
(6) Remove snap ring holding clutch sleeve onto
mainshaft.
Fig. 17 Oil Pickup Tube Removal
1 - OIL PICKUP TUBE
Fig. 18 Front Output Shaft, Drive Gear And Chain
Removal
1 - REAR HOUSING
2 - OUTPUT SHAFT AND SPROCKET
3 - MAINSHAFT SPROCKET
4 - SNAP-RING
5 - DRIVE CHAIN
Fig. 19 Detent Plug, Spring And Plunger Removal
1 - DETENT PLUG
2 - DETENT SPRING
3 - DETENT PLUNGER
4 - PLUG O-RING
WJTRANSFER CASE - NV247 21 - 321
TRANSFER CASE - NV247 (Continued)

(7) Remove range clutch sleeve, blockout spring,
locking clutch, and locking clutch spring from main-
shaft (Fig. 20).
(8) Remove shift sector. Rotate and tilt sector as
needed to remove it (Fig. 21).
(9) Remove shift sector bushing and O-ring (Fig.
22).
INPUT GEAR/LOW RANGE ASSEMBLY
(1) Turn front case on side so front bearing
retainer is accessible.
(2) Remove front bearing retainer bolts (Fig. 23).
(3) Remove front bearing retainer as follows:(a) Loosen retainer with flat blade screwdriver
to break sealer bead.To avoid damaging case
and retainer, position screwdriver blade only
in slots provided in retainer (Fig. 24).
(b) Then remove retainer from case and gear.
Fig. 20 Range Clutch Sleeve, Blockout Spring,
Locking Clutch and Spring
1 - LOCKING CLUTCH SPRING
2 - BLOCKOUT SPRING
3 - SNAP-RING
4 - RANGE CLUTCH SLEEVE
5 - LOCKING CLUTCH
6 - DRIVE SPROCKET HUB
Fig. 21 Shift Sector Removal
1 - SHIFT SECTOR
Fig. 22 Sector Bushing And O-Ring Removal
1 - SHIFT SECTOR BUSHING
2 - O-RING
Fig. 23 Front Bearing Retainer Bolt Removal
1 - FRONT BEARING RETAINER
21 - 322 TRANSFER CASE - NV247WJ
TRANSFER CASE - NV247 (Continued)

(7) Install snap-ring to hold input/low range gear
into front bearing (Fig. 47).
(8) Clean gasket sealer residue from retainer and
inspect retainer for cracks or other damage.
(9) Applya3mm(1/8 in.) bead of Mopartgasket
maker or silicone adhesive to sealing surface of
retainer.
(10) Align cavity in seal retainer with fluid return
hole in front of case.
CAUTION: Do not block fluid return cavity on seal-
ing surface of retainer when applying MoparTgas-
ket maker or silicone adhesive sealer. Seal failure
and fluid leak can result.
(11) Install bolts to hold retainer to transfer case
(Fig. 48). Tighten to 21 N´m (16 ft. lbs.) of torque.SHIFT FORKS AND MAINSHAFT
(1) Install new sector shaft O-ring and bushing
(Fig. 49).
(2) Install shift sector (Fig. 50).
(3) Install locking clutch spring, locking clutch,
blockout spring, and range clutch sleeve, to main-
shaft as shown in (Fig. 51). Install snap ring.
(4) Install drive sprocket hub to mainshaft and
manually load the needle bearings.
(5) Install new pads on range fork, if necessary.
Fig. 47 Install Input Gear Snap-Ring
1 - INPUT GEAR
2 - SNAP-RING
Fig. 48 Install Front Bearing Retainer
1 - FRONT BEARING RETAINER
Fig. 49 Sector O-Ring And Bushing Installation
1 - SECTOR BUSHING
2 - O-RING
Fig. 50 Shift Sector Installation
1 - SHIFT SECTOR
21 - 330 TRANSFER CASE - NV247WJ
TRANSFER CASE - NV247 (Continued)

(6) Install range shift fork to range clutch sleeve.
Install mainshaft/range shift fork assembly into
transfer case and input planetary assembly. Rotate
fork until it engages with slot in shift sector.
(7) Install shift rail to shift range fork and trans-
fer case housing.
(8) Rotate shift sector to NEUTRAL position.
(9) Install new O-ring on detent plug (Fig. 52).
(10) Lubricate detent plunger with transfer case
lubricant or light coat of petroleum jelly.
(11) Install detent plunger, spring and plug (Fig.
52).
(12)
Verify that plunger is properly engaged in sector.
FRONT OUTPUT SHAFT AND DRIVE CHAIN
(1) Lubricate front output shaft-sprocket assembly,
drive chain and drive sprocket with transfer case
lubricant.
(2) Assemble drive chain, drive sprocket and front
output shaft (Fig. 53).
(3) Start drive sprocket on mainshaft.
(4) Guide front shaft into bearing and drive
sprocket onto mainshaft drive gear (Fig. 53).
(5) Install drive sprocket snap-ring (Fig. 54).
Fig. 51 Range Clutch Sleeve, Blockout Spring,
Locking Clutch and Spring
1 - LOCKING CLUTCH SPRING
2 - BLOCKOUT SPRING
3 - SNAP-RING
4 - RANGE CLUTCH SLEEVE
5 - LOCKING CLUTCH
6 - DRIVE SPROCKET HUB
Fig. 52 Shift Detent Components
1 - DETENT PLUG
2 - DETENT SPRING
3 - DETENT PLUNGER
4 - PLUG O-RING
Fig. 53 Installing Drive Chain, Front Output Shaft
And Drive Sprocket
1 - FRONT OUTPUT SHAFT
2 - DRIVE CHAIN
3 - MAINSHAFT
4 - DRIVE GEAR
WJTRANSFER CASE - NV247 21 - 331
TRANSFER CASE - NV247 (Continued)

However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
air conditioning system on humid days. A perfor-
mance test is the best way to determine whether the
system is performing up to standard. This test also
provides valuable clues as to the possible cause of
trouble with the air conditioning system.
If the vehicle has the optional Automatic Zone Control
(AZC) system, and has intermittent operational prob-
lems or fault codes, be certain that the wire harness
connectors on the HVAC housing are properly seated
(Fig. 2). To check this condition, unplug the two wire
harness connector halves, then plug them in again.
Before performing the following procedure, (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - CAUTION) (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNING). The air
temperature in the test room and in the vehicle must
be a minimum of 21É C (70É F) for this test.
(1)
Connect a tachometer and a manifold gauge set.
(2) If the vehicle has the standard manual temper-
ature control, set the A/C Heater mode control switch
knob in the Panel position, the temperature control
knob in the full cool (Fresh Air Mode) position, the
A/C button in the On position, and the blower motor
switch knob in the highest speed position. If the vehi-
cle has the optional AZC, set the A/C Heater mode
control switch knob in the Panel position, the tem-
perature control knob in the full cool position, the
A/C button in the On position, and the blower motor
switch knob in the highest (manual) speed position.
(3) Start the engine and hold the idle at 1,300 rpm
with the compressor clutch engaged.
(4) The engine should be at operating temperature.
The doors and windows must be open.
(5)
Insert a thermometer in the driver side center
A/C (panel) outlet. Operate the engine for five minutes.
(6) The compressor clutch may cycle, depending
upon the ambient temperature and humidity.(7) With the compressor clutch engaged, record the
discharge air temperature and the compressor dis-
charge pressure.
(8) Compare the discharge air temperature to the
Performance Temperature and Pressure chart. If the
discharge air temperature is high, (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
DIAGNOSIS AND TESTING - REFRIGERANT SYS-
TEM LEAKS) and (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM CHARGE).
Performance Temperature and Pressure
Ambient Air Temperature
and Humidity21É C
(70É F @ 80%
humidity)27É C
(80É F @ 80%
humidity)32É C
(90É F @ 80%
humidity)38É C
(100ÉF@50%
humidity)43É C
110É F @ 20%
humidity)
Air Temperature at Center
Panel Outlet10 to 13É C
(50 to 55É F)14 to 17É C
(58 to 63É F)15 to 18É C
(60 to 65É F)17 to 20É C
(63 to 68É F)14 to 17É C
(58 to 63É F)
Evaporator Inlet Pressure
at Charge Port241 to 276 kPa
(35 to 40 psi)262 to 290 kPa
(38 to 42 psi)269 to 296 kPa
(39 to 43 psi)275 to 303 kPa
(40 to 44 psi)262 to 290 kPa
(38 to 42 psi)
Compressor Discharge
Pressure1241 to 1792
kPa
(180 to 260 psi)1380 to 1930
kPa
(200 to 280 psi)1380 to 1930
kPa
(200 to 280 psi)1655 to 2206
kPa
(240 to 320 psi)1567 to 2068
kPa
(220 to 300 psi)
Note: The discharge air temperatures will be lower if the humidity is less than the percentages shown.
Fig. 2 HVAC Housing - (rear view)
1 - Instrument Panel
2 - Air Intake
3 - Expansion Valve
4 - HVAC Housing
5 - Heater Core Input/Output Ports
6 - Instrument Panel Wiring Harness
7 - Blower Motor
WJHEATING & AIR CONDITIONING 24 - 3
HEATING & AIR CONDITIONING (Continued)

(9) Compare the compressor discharge pressure to
the Performance Temperature and Pressure chart. If
the compressor discharge pressure is high, see the
Pressure Diagnosis chart.
Pressure Diagnosis
Condition Possible Causes Correction
Rapid compressor clutch
cycling (ten or more cycles
per minute).1. Low refrigerant system
charge.1. See Plumbing/Diagnosis and Testing -
Refrigerant System Leaks in this group. Test the
refrigerant system for leaks. Repair, evacuate and
charge the refrigerant system, if required.
Equal pressures, but the
compressor clutch does not
engage.1. No refrigerant in the
refrigerant system.1. See Plumbing/Diagnosis and Testing -
Refrigerant System Leaks in this group. Test the
refrigerant system for leaks. Repair, evacuate and
charge the refrigerant system, if required.
2. Faulty fuse. 2. Check the fuses in the Power Distribution
Center and the junction block. Repair the shorted
circuit or component and replace the fuses, if
required.
3. Faulty a/c compressor
clutch coil.3. See A/C Compressor/Diagnosis and Testing -
Compressor Clutch Coil in this group. Test the
compressor clutch coil and replace, if required.
4. Faulty compressor clutch
relay.4. See A/C Compressor Clutch Relay/Diagnosis
and Testing - Compressor Clutch Relay in this
group. Test the compressor clutch relay and relay
circuits. Repair the circuits or replace the relay, if
required.
6. Faulty a/c high pressure
transducer.6. See A/C High Pressure Transducer/Diagnosis
and Testing in this group. Test the a/c high
pressure transducer and replace, if required.
7. Faulty Fin Probe. 7. Check for open circuit.
8. Faulty Powertrain Control
Module (PCM).8. Refer to the proper Diagnostic Procedures
manual for testing of the PCM. Test the PCM and
replace, if required.
Normal pressures, but A/C
Performance Test air
temperatures at center panel
outlet are too high.1. Excessive refrigerant oil in
system.1. See Refrigerant Oil/Standard Procedure -
Refrigerant Oil Level in this group. Recover the
refrigerant from the refrigerant system and
inspect the refrigerant oil content. Restore the
refrigerant oil to the proper level, if required.
2. Blend door inoperative or
sealing improperly.2. See Blend Door in this group. Inspect the
blend door for proper operation and sealing and
correct, if required.
3. Blend door actuator faulty
or inoperative.3. Perform blend door actuator diagnosis, replace
if faulty.
24 - 4 HEATING & AIR CONDITIONINGWJ
HEATING & AIR CONDITIONING (Continued)

(5) Install the new diode in the harness, making
sure current flow is correct. If necessary refer to the
appropriate wiring diagram for current flow.
(6) Solder the connection together using rosin core
type solder only.Do not use acid core solder.
(7) Tape the diode to the harness using electrical
tape making, sure the diode is completely sealed
from the elements.
(8) Re-connect the battery, and test affected sys-
tems.SPECIFICATIONS
A/C APPLICATION TABLE
Item Description Notes
VEHICLE WJ - Grand
Cherokee
SYSTEM R134a w/
expansion valve
COMPRESSOR Nippondenso
10PA17ND-8 PAG oil
Freeze±up
ControlEvaporator Probe Evaporator
mounted
Low psi Control opens < 22 psi -
resets > 34-38 psi
High psi Control opens > 450-490
psi - resets <
270-330 psiline mounted
CONTROL
HEADManual type manual
controls
Automatic Zone
Control (AZC)Automatic
Zone Control
(AZC) with
dual infrared
sensing
Mode Doors Vacuum actuators
(manual)electric
actuator
(AZC)
Blend Door Electric actuator (manual and
AZC)
Blend Door
(passenger)Electric actuator (AZC only)
Recirculation
DoorVacuum actuator
(manual)electric
actuator
(AZC)
Blower Motor Hardwired to
control head
resistor block
(manual),
blower
controller (AZC)
COOLING FAN Hybrid - viscous
clutch/electricPCM output
CLUTCH
Control Relay PCM
controlled
Draw
2.0-3.9 amps @ 12 V  0.5V@ 70É F
Gap 0.0169-0.0319
DRB IIIT
Reads TPS, RPM, A/C
switch
Actuators Clutch relay
WJHEATING & AIR CONDITIONING 24 - 7
HEATING & AIR CONDITIONING (Continued)

CONTROLS
TABLE OF CONTENTS
page page
CONTROLS
DIAGNOSIS AND TESTING - VACUUM
SYSTEM............................10
A/C COMPRESSOR CLUTCH
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL........................13
STANDARD PROCEDURE - COMPRESSOR
CLUTCH BREAK-IN....................14
REMOVAL.............................14
INSPECTION..........................15
INSTALLATION.........................15
A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - A/C
COMPRESSOR CLUTCH RELAY..........16
REMOVAL.............................17
INSTALLATION.........................17
A/C HEATER CONTROL
DESCRIPTION.........................17
OPERATION...........................17
DIAGNOSIS AND TESTING - AUTOMATIC
ZONE CONTROL SYSTEM..............18
REMOVAL.............................24
INSTALLATION.........................25
A/C PRESSURE TRANSDUCER
DESCRIPTION.........................25
OPERATION...........................25
DIAGNOSIS AND TESTING - A/C PRESSURE
TRANSDUCER.......................26
REMOVAL.............................26
INSTALLATION.........................26
BLOWER MOTOR CONTROLLER
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................27
INSTALLATION.........................27
BLOWER MOTOR RESISTOR BLOCK
DESCRIPTION.........................27
OPERATION...........................27
DIAGNOSIS AND TESTING - BLOWER
MOTOR RESISTOR BLOCK..............27
REMOVAL.............................28
INSTALLATION.........................28BLOWER MOTOR SWITCH
DESCRIPTION.........................28
OPERATION...........................28
DIAGNOSIS AND TESTING - BLOWER
MOTOR SWITCH-MANUAL TEMPERATURE
CONTROL SYSTEM....................28
REMOVAL.............................29
IN-CAR TEMPERATURE SENSOR
DESCRIPTION.........................29
OPERATION...........................29
REMOVAL.............................29
BLEND DOOR ACTUATOR
DESCRIPTION.........................30
REMOVAL.............................30
INSTALLATION.........................30
MODE DOOR ACTUATOR
DESCRIPTION.........................30
REMOVAL
REMOVAL - HEAT/DEFROST - PANEL/
DEFROST DOOR ELECTRIC ACTUATOR . . . 31
REMOVAL - HEAT/DEFROST DOOR
VACUUM ACTUATOR..................31
REMOVAL - PANEL/DEFROST DOOR
VACUUM ACTUATOR..................32
INSTALLATION
INSTALLATION - HEAT/DEFROST -
PANEL/DEFROST DOOR ELECTRIC
ACTUATOR..........................32
INSTALLATION - HEAT/DEFROST DOOR
VACUUM ACTUATOR..................33
INSTALLATION - PANEL/DEFROST DOOR
VACUUM ACTUATOR..................33
RECIRCULATION DOOR ACTUATOR
DESCRIPTION.........................33
REMOVAL
REMOVAL - RECIRCULATION DOOR
VACUUM ACTUATOR..................33
REMOVAL - RECIRCULATION DOOR
ELECTRIC ACTUATOR.................33
INSTALLATION
INSTALLATION - RECIRCULATION DOOR
VACUUM ACTUATOR..................34
INSTALLATION - RECIRCULATION DOOR
ELECTRIC ACTUATOR.................34
VACUUM CHECK VALVE
DESCRIPTION.........................34
OPERATION...........................34
REMOVAL.............................34
INSTALLATION.........................34
WJCONTROLS 24 - 9