compressor clutch JEEP GRAND CHEROKEE 2002 WJ / 2.G Owner's Manual

OPERATION
To apply the clutch, pressure is applied between
the clutch retainer and piston. The fluid pressure is
provided by the oil pump, transferred through the
control valves and passageways, and enters the
clutch through the hub of the reaction shaft support.
With pressure applied between the clutch retainer
and piston, the piston moves away from the clutch
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow
through the input shaft into the driving discs, and
into the clutch plates and pressure plate that are
lugged to the clutch retainer. The waved snap-ring is
used to cushion the application of the clutch pack.
When pressure is released from the piston, the
spring returns the piston to its fully released position
and disengages the clutch. The release spring also
helps to cushion the application of the clutch assem-
bly. When the clutch is in the process of being
released by the release spring, fluid flows through a
vent and one-way ball-check-valve located in the
clutch retainer. The check-valve is needed to elimi-
nate the possibility of plate drag caused by centrifu-
gal force acting on the residual fluid trapped in the
clutch piston retainer.
DISASSEMBLY
(1) Remove waved snap-ring and remove pressure
plate, clutch plates and clutch discs (Fig. 92).
(2) Compress clutch piston spring with Compressor
Tool C-3575-A (Fig. 93). Be sure legs of tool are
seated squarely on spring retainer before compress-
ing spring.
(3) Remove retainer snap-ring and remove com-
pressor tool.
(4) Remove spring retainer and clutch spring. Note
position of retainer on spring for assembly reference.
(5) Remove clutch piston from clutch retainer.
Remove piston by rotating it up and out of retainer.
(6) Remove seals from clutch retainer piston bore
and clutch retainer hub. Discard both seals as they
are not reusable.
INSPECTION
Inspect the front clutch components. Replace the
clutch discs if warped, worn, scored, burned or
charred, or if the facing is flaking off. Replace the
steel plates if heavily scored, warped, or broken. Be
sure the driving lugs on the plates are in good con-
dition. The lugs must not be bent, cracked or dam-
aged in any way.
Replace the clutch spring and spring retainer if
either is distorted, warped or broken.Check the lug grooves in the clutch retainer. The
steel plates should slide freely in the slots. Replace
the retainer if the grooves are worn or damaged.
Check action of the check ball in the retainer (Fig.
94). The ball must move freely and not stick.
NOTE: Inspect the clutch retainer bushings care-
fully (Fig. 95). The retainer bushings are NOT ser-
viceable. It will be necessary to replace the retainer
if either bushing is scored, or worn.
Inspect the piston and retainer seal surfaces for
nicks or scratches. Minor scratches can be removed
with crocus cloth. However, replace the piston and/or
retainer if the seal surfaces are seriously scored.
ASSEMBLY
NOTE: The 42RE transmission uses four plates and
discs for the front clutch.
(1) Soak clutch discs in transmission fluid while
assembling other clutch parts.
(2) Install new seals in the clutch retainer lower
groove and on outer diameter of the retainer hub. Be
sure lip of each seal faces interior of clutch retainer.
(3) Lubricate lips of the retainer seals with liberal
quantity of MopartDoor Ease. Then lubricate
retainer hub, bore and piston with light coat of trans-
mission fluid.
(4) Install clutch piston in retainer (Fig. 96). Use
twisting motion to seat piston in bottom of retainer.
CAUTION: Never push the clutch piston straight in.
This will fold the seals over causing leakage and
clutch slip.
(5) Position spring in clutch piston (Fig. 97).
(6) Position spring retainer on top of piston spring.
Make sure retainer is properly installed (Fig. 92).
(7) Compress piston spring and retainer with Com-
pressor Tool C-3575-A (Fig. 93). Then install new
snap-ring to secure spring retainer and spring.
(8) Install clutch plates and discs (Fig. 92). Install
steel plate then disc until all plates and discs are
installed. The front clutch uses 4 clutch discs and
plates in a 42RE transmission.
(9) Install pressure plate and waved snap-ring
(Fig. 92).
Clearance should be 1.70 to 3.40 mm (0.067 to
0.134 in.). If clearance is incorrect, clutch discs,
plates, pressure plates and snap-ring may have to be
changed.
21 - 74 AUTOMATIC TRANSMISSION - 42REWJ
FRONT CLUTCH (Continued)

Fig. 93 Compressing Front Clutch Piston Spring
1 - FRONT CLUTCH SPRING
2 - COMPRESSOR TOOL C-3575-A
3 - RETAINER SNAP-RING
4 - SPRING RETAINER
Fig. 94 Front Clutch Piston Retainer Check Ball
Location
1 - RETAINER CHECK BALL
Fig. 95 Retainer Bushing Location/Inspection
1 - FRONT CLUTCH RETAINER BUSHINGS (NON-
SERVICEABLE)
Fig. 96 Front Clutch Piston Installation
1 - CLUTCH PISTON
2 - FRONT CLUTCH RETAINER
Fig. 97 Clutch Piston Spring Installation
1 - RETAINER
2 - CLUTCH SPRING
3 - PISTON
21 - 76 AUTOMATIC TRANSMISSION - 42REWJ
FRONT CLUTCH (Continued)

DIRECT CLUTCH, HUB AND SPRING
WARNING: THE NEXT STEP IN DISASSEMBLY
INVOLVES COMPRESSING THE DIRECT CLUTCH
SPRING. IT IS EXTREMELY IMPORTANT THAT
PROPER EQUIPMENT BE USED TO COMPRESS
THE SPRING AS SPRING FORCE IS APPROXI-
MATELY 830 POUNDS. USE SPRING COMPRESSOR
TOOL 6227-1 AND A HYDRAULIC SHOP PRESS
WITH A MINIMUM RAM TRAVEL OF 5-6 INCHES.
THE PRESS MUST ALSO HAVE A BED THAT CAN
BE ADJUSTED UP OR DOWN AS REQUIRED.
RELEASE CLUTCH SPRING TENSION SLOWLY AND
COMPLETELY TO AVOID PERSONAL INJURY.(1) Mount geartrain assembly in shop press (Fig.
142).
(2) Position Compressor Tool 6227-1 on clutch hub
(Fig. 142). Support output shaft flange with steel
press plates as shown and center assembly under
press ram.
(3) Apply press pressure slowly. Compress hub and
spring far enough to expose clutch hub retaining ring
and relieve spring pressure on clutch pack snap-ring
(Fig. 142).
(4) Remove direct clutch pack snap-ring (Fig. 143).
(5) Remove direct clutch hub retaining ring (Fig.
144).
(6) Release press load slowly and completely (Fig.
145).
(7) Remove Special Tool 6227-1. Then remove
clutch pack from hub (Fig. 145).
GEARTRAIN
(1) Remove direct clutch hub and spring (Fig. 146).
Fig. 140 Removing Gear Case From Geartrain
Assembly
1 - GEARTRAIN ASSEMBLY
2 - GEAR CASE
Fig. 141 Rear Bearing Removal
1 - OUTPUT SHAFT
2 - REAR BEARING
3 - SNAP-RING
Fig. 142 Geartrain Mounted In Shop Press
1 - PRESS RAM
2 - SPECIAL TOOL C-3995-A (OR SIMILAR TOOL)
3 - CLUTCH HUB
4 - PLATES
5 - PRESS BED
6 - SPECIAL TOOL 6227-1
WJAUTOMATIC TRANSMISSION - 42RE 21 - 91
OVERDRIVE UNIT (Continued)

WARNING: THE NEXT STEP IN GEARTRAIN
ASSEMBLY INVOLVES COMPRESSING THE DIRECT
CLUTCH HUB AND SPRING. IT IS EXTREMELY
IMPORTANT THAT PROPER EQUIPMENT BE USED
TO COMPRESS THE SPRING AS SPRING FORCE IS
APPROXIMATELY 830 POUNDS. USE COMPRES-
SOR TOOL C-6227-1 AND A HYDRAULIC-TYPE
SHOP PRESS WITH A MINIMUM RAM TRAVEL OF 6
INCHES. THE PRESS MUST ALSO HAVE A BED
THAT CAN BE ADJUSTED UP OR DOWN AS
REQUIRED. RELEASE CLUTCH SPRING TENSION
SLOWLY AND COMPLETELY TO AVOID PERSONAL
INJURY.
(20) Position Compressor Tool 6227-1 on clutch
hub.
(21) Compress clutch hub and spring just enough
to place tension on hub and hold it in place.
(22) Slowly compress clutch hub and spring. Com-
press spring and hub only enough to expose ring
grooves for clutch pack snap ring and clutch hub
retaining ring.
(23) Realign clutch pack on hub and seat clutch
discs and plates in clutch drum.
(24) Install direct clutch pack snap-ring (Fig. 171).
Be very sure snap-ring is fully seated in clutch drum
ring groove.
(25) Install clutch hub retaining ring (Fig. 172). Be
very sure retaining ring is fully seated in sun gear
ring groove.
(26) Slowly release press ram, remove compressor
tools and remove geartrain assembly.
GEAR CASE
(1) Position park pawl and spring in case and
install park pawl shaft. Verify that end of spring
with 90É bend is hooked to pawl and straight end of
spring is seated against case.
(2) Install pawl shaft retaining bolt. Tighten bolt
to 27 N´m (20 ft. lbs.) torque.
(3) Install park lock reaction plug. Note that plug
has locating pin at rear (Fig. 173). Be sure pin is
seated in hole in case before installing snap-ring.
(4) Install reaction plug snap-ring (Fig. 174). Com-
press snap ring only enough for installation; do not
distort it.
Fig. 170 Direct Clutch
1 - CLUTCH HUB
2 - DIRECT CLUTCH PACK
3 - CLUTCH DRUM
Fig. 171 Direct Clutch Pack Snap-Ring Installation
1 - SPECIAL TOOL 6227-1
2 - DIRECT CLUTCH PACK SNAP-RING
Fig. 172 Clutch Hub Retaining Ring Installation
1 - SPECIAL TOOL 6227-1
2 - CLUTCH HUB RETAINING RING
21 - 100 AUTOMATIC TRANSMISSION - 42REWJ
OVERDRIVE UNIT (Continued)

Fixture, Input Clutch Pressure - 8260
Plate, Alignment - 8261
End Play Set - 8266
Compressor, Spring - 8285
Installer, Bearing - 8320
Wrench, Filter - 8321
Installer, Piston - 8504
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 223
AUTOMATIC TRANSMISSION - 545RFE (Continued)

4C RETAINER/BULKHEAD
DISASSEMBLY
(1) Remove the 2C piston belleville spring snap-
ring from the 4C retainer /bulkhead (Fig. 53).
(2) Remove the 2C piston Belleville spring from
the retainer/bulkhead (Fig. 53).
(3) Remove the 2C piston from the retainer/bulk-
head. Use 20 psi of air pressure to remove the piston
if necessary.
(4) Remove the 4C clutch snap-ring from the
retainer/bulkhead (Fig. 53).
(5) Remove the 4C clutch pack from the retainer/
bulkhead (Fig. 53).
(6) Using Spring Compressor 8250 and a suitable
shop press, compress the 4C piston return spring and
remove the snap-ring (Fig. 53).(7) Remove the 4C piston return spring and piston
from the retainer/bulkhead (Fig. 53). Use 20 psi of
air pressure to remove the piston if necessary.ASSEMBLY
(1) Clean and inspect all components. Replace any
components which show evidence of excessive wear
or scoring.
(2) Install new seals on the 2C and 4C pistons
(Fig. 53).
(3) Lubricate all seals with MopartATF +4, type
9602 prior to installation.
(4) Install the 4C piston into the 4C retainer/bulk-
head (Fig. 53).
(5) Position the 4C piston return spring onto the
4C piston.
Fig. 53 4C Retainer/Bulkhead Components
1 - SEAL 8 - REACTION PLATE
2 - 2C PISTON 9 - SNAP-RING
3 - PLATE 10 - RETURN SPRING
4 - DISC 11 - SEAL
5 - 2C BELLEVILLE SPRING 12 - 4C PISTON
6 - SNAP-RING 13 - 4C RETAINER/BULKHEAD
7 - SNAP-RING (SELECT)
21 - 224 AUTOMATIC TRANSMISSION - 545RFEWJ

(6) Using Spring Compressor 8250 and a suitable
shop press, compress the 4C piston return spring and
install the snap-ring (Fig. 54).
(7) Assemble and install the 4C clutch pack into
the retainer/bulkhead (Fig. 53) with the steel separa-
tor plate against the piston.
(8) Install the 4C reaction plate and snap-ring into
the retainer/bulkhead (Fig. 53). The 4C reaction plate
is non-directional.
(9) Measure the 4C clutch clearance. The correct
clutch clearance is 0.77-1.39 mm (0.030-0.055 in.).
The snap-ring is selectable. Install the chosen snap-
ring and re-measure to verify the selection.
(10) Install the 2C piston into the retainer/bulk-
head (Fig. 53).
(11) Position the 2C Belleville spring onto the 2C
piston.
(12) Position the 2C Belleville spring snap-ring
onto the 2C Belleville spring (Fig. 53).
(13) Using Spring Compressor 8249 and a suitable
shop press (Fig. 55), compress the belleville spring
until the snap-ring is engaged with the snap-ring
groove in the retainer/bulkhead.
ADAPTER HOUSING SEAL
REMOVAL
(1) Remove the transfer case from the transmis-
sion.
(2) Using a screw mounted on a slide hammer,
remove the adapter housing seal.
INSTALLATION
(1) Clean the adapter seal bore in the adapter
housing of any residue or particles remaining from
the original seal.
(2) Install new oil seal in the adapter housing
using Seal Installer C-3860-A (Fig. 56). A properly
installed seal is flush to the face of the seal bore.
(3) Install the transfer case onto the transmission.
Fig. 54 Compress 4C Piston Return Spring Using
Tool 8250
1 - PRESS
2 - TOOL 8250
Fig. 55 Compress 2C Belleville Spring Using Tool
8249
1 - PRESS
2 - TOOL 8249
Fig. 56 Adapter Housing Seal Installation
1 - TOOL C-3860-A
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 225
4C RETAINER/BULKHEAD (Continued)

(9) Remove the number 2 bearing from the input
clutch hub.
(10) Remove the overdrive clutch wave snap-ring
from the input clutch retainer.
(11) Remove the UD/OD reaction plate tapered
snap-ring from the input clutch retainer.
(12) Remove the UD/OD reaction plate from the
input clutch retainer.
(13) Remove the UD/OD reaction plate flat snap-
ring from the input clutch retainer (Fig. 70).
(14) Remove the underdrive clutch pack from the
input clutch retainer (Fig. 72).
(15) Using Spring Compressor 8251, compress the
UD/OD balance piston and remove the snap-ring
from the input clutch hub (Fig. 71).
(16) Remove the UD/OD balance piston and piston
return spring from the input clutch retainer (Fig. 72).
(17) Remove the underdrive piston from the input
clutch retainer (Fig. 72).NOTE: Both the UD/OD balance piston and the
underdrive piston have seals molded onto them. If
the seal is damaged, do not attempt to install a new
seal onto the piston. The piston/seal must be
replaced as an assembly.
(18) Remove the input clutch retainer tapered
snap-ring.
(19) Separate input clutch retainer from input
clutch hub.
(20) Separate OD/reverse piston from input clutch
hub retainer (Fig. 72).
(21) Remove all seals and o-rings from the input
shaft and input hub. The o-rings on the input hub
are color coded. Be sure to make note of which o-ring
belongs in which location.
ASSEMBLY
(1) Install all new seals and o-rings onto the input
shaft and input hub. The o-rings on the input hub
are color coded. Be sure to install the correct o-ring
in the correct location.
(2) Check the transmission lubrication check valve
located in the input shaft using shop air. The valve
should only allow air flow in one direction. If the
valve allows no air flow, or air flow in both direc-
tions, the valve will need to be replaced.
(3) Lubricate all seals with MopartATF +4, type
9602, prior to installation.
(4) Assemble the OD/reverse piston onto the input
clutch hub (Fig. 73).
(5) Assemble the input clutch retainer onto the
input clutch hub.
(6) Install the input clutch retainer tapered snap-
ring with tapered side up onto the input clutch hub.
Fig. 71 Compressing UD/OD Balance Piston Using
Tool 8251
1 - PRESS
2 - TOOL 8251
3 - BALANCE PISTON
21 - 238 AUTOMATIC TRANSMISSION - 545RFEWJ
INPUT CLUTCH ASSEMBLY (Continued)

(7) Install Piston Guides 8504 into the input clutch
retainer (Fig. 74) and onto the input clutch hub to
guide the inner and outer underdrive piston seals
into position.
(8) Install the underdrive piston into the input
clutch retainer and over the input clutch hub (Fig.
73).
(9) Install the UD/OD balance piston return spring
pack into the input clutch retainer.
(10) Install Piston Guide 8252 into the input
clutch retainer (Fig. 75) to guide the UD/OD balance
piston seal into position inside the underdrive piston.(11) Install the UD/OD balance piston into the
input clutch retainer and the underdrive piston.
(12) Using Spring Compressor 8251, compress the
UD/OD return spring pack and secure the piston in
place with the snap-ring (Fig. 76).
Fig. 74 Install Underdrive Piston Using Tool 8504
1 - TOOL 8504
Fig. 75 Install Balance Piston Using Tool 8252
1 - TOOL 8252
Fig. 76 Compressing UD/OD Balance Piston Using
Tool 8251
1 - PRESS
2 - TOOL 8251
3 - BALANCE PISTON
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 241
INPUT CLUTCH ASSEMBLY (Continued)

LOW/REVERSE CLUTCH
DISASSEMBLY
(1) Remove the inner overrunning clutch snap-ring
from the low/reverse clutch retainer (Fig. 84).
(2) Remove the outer low/reverse reaction plate
flat snap-ring (Fig. 84).
(3) Remove the low/reverse clutch and the over-
running clutch from the low/reverse clutch retainer
as an assembly (Fig. 84).
(4) Separate the low/reverse clutch from the over-
running clutch.(5) Remove the overrunning clutch snap-ring (Fig.
85).
(6) Remove the spacer from the overrunning clutch
(Fig. 85).
(7) Separate the inner and outer races of the over-
running clutch (Fig. 85).
(8) Remove the overrunning clutch lower snap-ring
(Fig. 85).
(9) Using Spring Compressor 8285 and a suitable
shop press (Fig. 86), compress the low/reverse piston
Belleville spring and remove the split retaining ring
Fig. 84 Low/Reverse Clutch Assembly
1 - SNAP-RING (SELECT) 8 - SEAL
2 - REACTION PLATE 9 - BELLEVILLE SPRING
3 - DISC 10 - RETAINER
4 - PLATE 11 - SNAP-RING
5 - L/R CLUTCH RETAINER 12 - OVERRUNNING CLUTCH
6 - SEAL 13 - SNAP-RING
7 - PISTON
21 - 246 AUTOMATIC TRANSMISSION - 545RFEWJ