2002 JEEP GRAND CHEROKEE Gear

REMOVAL
The overdrive unit can be removed and serviced
separately. It is not necessary to remove the entire
transmission assembly to perform overdrive unit
repairs.
If only the overdrive unit requires service, refer to
Overdrive Removal for proper procedures.
CAUTION: The transmission and torque converter
must be removed as an assembly to avoid compo-
nent damage. The converter driveplate, pump bush-
ing, or oil seal can be damaged if the converter is
left attached to the driveplate during removal. Be
sure to remove the transmission and converter as
an assembly.
(1) Disconnect battery negative cable.
(2) Disconnect and lower or remove necessary
exhaust components.
(3) Disconnect fluid cooler lines at transmission.
(4) Remove starter motor. (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL)
(5) Disconnect and remove crankshaft position sen-
sor. (Refer to 14 - FUEL SYSTEM/FUEL INJEC-
TION/CRANKSHAFT POSITION SENSOR -
REMOVAL) Retain sensor attaching bolts.
CAUTION: The crankshaft position sensor will be
damaged if the transmission is removed, or
installed, while the sensor is still bolted to the
engine block, or transmission (4.0L only). To avoid
damage, be sure to remove the sensor before
removing the transmission.
(6) Remove the bolts holding the bell housing
brace to the transmission.
(7) Remove nut holding the bell housing brace to
the engine to transmission bending brace.
(8) Remove the bell housing brace from the trans-
mission (Fig. 13).
(9) Remove the bolt holding the torque converter
cover to the transmission.
(10) Remove the torque converter cover from the
transmission.
(11) If transmission is being removed for overhaul,
remove transmission oil pan, drain fluid and reinstall
pan.
(12) Remove fill tube bracket bolts and pull tube
out of transmission. Retain fill tube seal. On4x4
models, it will also be necessary to remove bolt
attaching transfer case vent tube to converter hous-
ing.
(13) Rotate crankshaft in clockwise direction until
converter bolts are accessible. Then remove bolts one
at a time. Rotate crankshaft with socket wrench on
dampener bolt.(14) Mark propeller shaft and axle yokes for
assembly alignment. Then disconnect and remove
propeller shaft. On4x4models, remove both propel-
ler shafts.
(15) Disconnect wires from park/neutral position
switch and transmission solenoid.
(16) Disconnect gearshift cable from transmission
manual valve lever (Fig. 14).
Fig. 13 Bell Housing Brace and Converter Cover
1 - Transmission
2 - Torque Converter Cover
3 - Bellhousing Brace
Fig. 14 Transmission Shift Cable
1 - SHIFT CABLE
2 - MANUAL LEVER
3 - MANUAL LEVER
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AUTOMATIC TRANSMISSION - 42RE (Continued)

(27) Remove planetary geartrain as assembly (Fig.
34). Support geartrain with both hands during
removal. Do not allow machined surfaces on interme-
diate shaft or overdrive piston retainer to become
nicked or scratched.
(28) If overdrive unit is not to be serviced, install
Alignment Shaft 6227-2 into the overdrive unit to
prevent misalignment of the overdrive clutches dur-
ing service of main transmission components.
Fig. 30 Separating Front/Rear Clutch Assemblies
1 - FRONT CLUTCH
2 - REAR CLUTCH
Fig. 31 Removing Intermediate Shaft Thrust Washer
1 - INTERMEDIATE SHAFT THRUST WASHER
2 - INPUT SHAFT
3 - REAR CLUTCH RETAINER HUB
Fig. 32 Removing Intermediate Shaft Thrust Plate
1 - INTERMEDIATE SHAFT HUB
2 - INTERMEDIATE SHAFT THRUST PLATE
Fig. 33 Front Band Removal
1 - DRIVING SHELL
2 - FRONT BAND
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AUTOMATIC TRANSMISSION - 42RE (Continued)

(29) Loosen rear band adjusting screw 4-5 turns.
(30) Remove low-reverse drum snap-ring (Fig. 35).(31) Remove low-reverse drum and reverse band.
(32) Remove overrunning clutch roller and spring
assembly as a unit (Fig. 36).
(33) Compress front servo rod guide about 1/8 inch
with Valve Spring Compressor C-3422-B (Fig. 37).
(34) Remove front servo rod guide snap-ring. Exer-
cise caution when removing snap-ring. Servo bore
can be scratched or nicked if care is not exercised.
(35) Remove compressor tools and remove front
servo rod guide, spring and servo piston.
Fig. 34 Removing Planetary Geartrain And
Intermediate Shaft Assembly
1 - PLANETARY GEARTRAIN AND INTERMEDIATE SHAFT
ASSEMBLY
Fig. 35 Removing Low-Reverse Drum Snap-Ring
1 - LOW-REVERSE DRUM
2 - HUB OF OVERDRIVE PISTON RETAINER
3 - LOW-REVERSE DRUM SNAP-RING
Fig. 36 Overrunning Clutch Assembly Removal
1 - OVERRUNNING CLUTCH CAM
2 - REAR BAND REACTION PIN
3 - OVERRUNNING CLUTCH ASSEMBLY
Fig. 37 Compressing Front Servo Rod Guide
1 - SPRING COMPRESSOR TOOL C-3422-B
2 - ROD GUIDE SNAP-RING
WJAUTOMATIC TRANSMISSION - 42RE 21 - 33
AUTOMATIC TRANSMISSION - 42RE (Continued)

(36) Compress rear servo spring retainer about
1/16 inch with Valve Spring Compressor C-3422-B
(Fig. 38).
(37) Remove rear servo spring retainer snap-ring.
Then remove compressor tools and remove rear servo
spring and piston.
(38) Inspect transmission components.
NOTE: To Service the overrunning clutch cam or
overdrive piston retainer, refer to the Overrunning
Clutch Cam service procedure in this section.
CLEANING
Clean the case in a solvent tank. Flush the case
bores and fluid passages thoroughly with solvent.
Dry the case and all fluid passages with compressed
air. Be sure all solvent is removed from the case and
that all fluid passages are clear.
NOTE: Do not use shop towels or rags to dry the
case (or any other transmission component) unless
they are made from lint-free materials. Lint will stick
to case surfaces and transmission components and
circulate throughout the transmission after assem-
bly. A sufficient quantity of lint can block fluid pas-
sages and interfere with valve body operation.Lubricate transmission parts with MopartATF +4,
type 9602, transmission fluid during overhaul and
assembly. Use petroleum jelly, MopartDoor Ease, or
Ru-GlydeŸ to prelubricate seals, O-rings, and thrust
washers. Petroleum jelly can also be used to hold
parts in place during reassembly.
INSPECTION
Inspect the case for cracks, porous spots, worn
bores, or damaged threads. Damaged threads can be
repaired with Helicoil thread inserts. However, the
case will have to be replaced if it exhibits any type of
damage or wear.
Lubricate the front band adjusting screw threads
with petroleum jelly and thread the screw part-way
into the case. Be sure the screw turns freely.
Inspect the transmission bushings during overhaul.
Bushing condition is important as worn, scored bush-
ings contribute to low pressures, clutch slip and
accelerated wear of other components. However, do
not replace bushings as a matter of course. Replace
bushings only when they are actually worn, or
scored.
Use recommended tools to replace bushings. The
tools are sized and designed to remove, install, and
seat bushings correctly. The bushing replacement
tools are included in Bushing Tool Set C-3887-B.
Pre-sized service bushings are available for
replacement purposes. Only the sun gear bushings
are not serviced.
The use of crocus cloth is permissible where neces-
sary, providing it is used carefully. When used on
shafts, or valves, use extreme care to avoid rounding
off sharp edges. Sharp edges are vital as they pre-
vent foreign matter from getting between the valve
and valve bore.
Do not reuse oil seals, gaskets, seal rings, or
O-rings during overhaul. Replace these parts as a
matter of course. Also do not reuse snap rings or
E-clips that are bent or distorted. Replace these parts
as well.
ASSEMBLY
Do not allow dirt, grease, or foreign material to
enter the case or transmission components during
assembly. Keep the transmission case and compo-
nents clean. Also make sure the tools and workbench
area used for assembly operations are equally clean.
Shop towels used for wiping off tools and hands
must be made fromlint freematerial. Lint will stick
to transmission parts and could interfere with valve
operation, or even restrict fluid passages.
Lubricate the transmission components with
Moparttransmission fluid during reassembly. Use
MopartDoor Ease, or Ru-GlydeŸ on seals and
O-rings to ease installation.
Fig. 38 Compressing Rear Servo Spring
1 - FRONT SERVO SNAP-RING
2 - REAR SERVO SNAP-RING
3 - SPECIAL TOOL
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AUTOMATIC TRANSMISSION - 42RE (Continued)

Petroleum jelly can also be used to hold thrust
washers, thrust plates and gaskets in position during
assembly. However,do notuse chassis grease, bear-
ing grease, white grease, or similar lubricants on any
transmission part. These types of lubricants can
eventually block or restrict fluid passages and inter-
fere with valve operation. Use petroleum jelly only.
Do not force parts into place. The transmission
components and subassemblies are easily installed by
hand when properly aligned.
If a part seems extremely difficult to install, it is
either misaligned or incorrectly assembled. Also ver-
ify that thrust washers, thrust plates and seal rings
are correctly positioned before assembly. These parts
can interfere with proper assembly if mis-positioned.
The planetary geartrain, front/rear clutch assem-
blies and oil pump are all much easier to install
when the transmission case is upright.
(1) Install rear servo piston, spring and retainer
(Fig. 39). Install spring on top of servo piston and
install retainer on top of spring.
(2) Install front servo piston assembly, servo
spring and rod guide (Fig. 40).
(3) Compress front/rear servo springs with Valve
Spring Compressor C-3422-B and install each servo
snap-ring (Fig. 41).
(4) Lubricate clutch cam rollers with transmission
fluid.
(5) Install rear band in case (Fig. 42). Be sure twin
lugs on band are seated against reaction pin.
(6) Install low-reverse drum and check overrun-
ning clutch operation as follows:(a) Lubricate overrunning clutch race (on drum
hub) with transmission fluid.
(b) Guide drum through rear band.
(c) Tilt drum slightly and start race (on drum
hub) into overrunning clutch rollers.
(d) Press drum rearward and turn it in clock-
wise direction until drum seats in overrunning
clutch (Fig. 43).
Fig. 39 Rear Servo Components
1 - SERVO PISTON
2 - PISTON SPRING
3 - SNAP-RING
4 - RETAINER
5 - PISTON SEAL
Fig. 40 Front Servo Components
1 - PISTON SEAL RINGS
2 - SERVO PISTON
3 - SNAP-RING
4 - ROD GUIDE
5 - SPRING
6 - ROD
Fig. 41 Compressing Front/Rear Servo Springs
1 - SPRING COMPRESSOR TOOL C-3422-B
2 - ROD GUIDE SNAP-RING
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AUTOMATIC TRANSMISSION - 42RE (Continued)

(e) Turn drum back and forth. Drum should
rotate freely in clockwise direction and lock in
counterclockwise direction (as viewed from front of
case).(7) Install snap-ring that secures low-reverse drum
to hub of overdrive piston retainer (Fig. 44).
(8) Install rear band lever and pivot pin (Fig. 45).
Align lever with pin bores in case and push pivot pin
into place.
(9) Install planetary geartrain assembly (Fig. 46).
Fig. 42 Rear Band Installation
1 - REAR BAND
Fig. 43 Installing Low-Reverse Drum
1 - REAR BAND
2 - LOW-REVERSE DRUM
Fig. 44 Installing Low-Reverse Drum Retaining
Snap-Ring
1 - LOW-REVERSE DRUM
2 - HUB OF OVERDRIVE PISTON RETAINER
3 - LOW-REVERSE DRUM SNAP-RING
Fig. 45 Rear Band Lever And Pivot Pin Installation
1 - REAR BAND LEVER
2 - LEVER PIVOT PIN
21 - 36 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

(10) Install thrust plate on intermediate shaft hub
(Fig. 47). Use petroleum jelly to hold thrust plate in
place.
(11) Check seal ring on rear clutch retainer hub
and seal rings on input shaft (Fig. 48). Also verify
that shaft seal rings are installed in sequence shown.
(12) Install rear clutch thrust washer (Fig. 49).
Use additional petroleum jelly to hold washer in
place if necessary.
(13) Align clutch discs in front clutch and install
front clutch on rear clutch (Fig. 50). Rotate front
clutch retainer back and forth until completely
seated on rear clutch retainer.
(14) Coat intermediate shaft thrust washer with
petroleum jelly. Then install washer in rear clutch
hub (Fig. 51). Use enough petroleum jelly to hold
washer in place. Be sure grooved side of washer faces
rearward (toward output shaft) as shown. Also note
that washer only fits one way in clutch hub. Note
thickness of this washer. It is a select fit part and is
used to control transmission end play.
Fig. 46 Installing Planetary Geartrain
1 - PLANETARY GEARTRAIN AND INTERMEDIATE SHAFT
ASSEMBLY
Fig. 47 Installing Intermediate Shaft Thrust Plate
1 - INTERMEDIATE SHAFT HUB
2 - INTERMEDIATE SHAFT THRUST PLATE
Fig. 48 Input Shaft Seal Ring Location
1 - INPUT SHAFT
2 - TEFLON SEAL RING
3 - PLASTIC SEAL RING
4 - REAR CLUTCH RETAINER
Fig. 49 Installing Rear Clutch Thrust Washer
1 - REAR CLUTCH RETAINER
2 - REAR CLUTCH THRUST WASHER (FIBER)
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AUTOMATIC TRANSMISSION - 42RE (Continued)

(15) Align drive teeth on rear clutch discs with
small screwdriver (Fig. 52). This makes installation
on front planetary easier.
(16) Raise front end of transmission upward as far
as possible and support case with wood blocks. Front/
rear clutch and oil pump assemblies are easier to
install if transmission is as close to upright position
as possible.
(17) Slide front band into case.
(18) Install front and rear clutch units as assembly
(Fig. 53). Align rear clutch with front annulus gear
and install assembly in driving shell. Be sure output
shaft thrust washer and thrust plate are not dis-
placed during installation.
(19) Carefully work assembled clutches back and
forth to engage and seat rear clutch discs on front
annulus gear. Also be sure front clutch drive lugs are
fully engaged in slots of driving shell after installa-
tion.
(20) Assemble front band strut.
(21) Install front band adjuster, strut and adjust-
ing screw (Fig. 54).
(22) Tighten band adjusting screw until band just
grips clutch retainer. Verify that front/rear clutches
are still seated before continuing.
Fig. 50 Assembling Front And Rear Clutch Units
1 - TURN FRONT CLUTCH BACK & FORTH UNTIL SEATED
2 - REAR CLUTCH ASSEMBLY
Fig. 51 Installing Intermediate Shaft Thrust Washer
1 - INTERMEDIATE SHAFT THRUST WASHER
2 - INPUT SHAFT
3 - REAR CLUTCH RETAINER HUB
Fig. 52 Aligning Rear Clutch Disc Lugs
1 - REAR CLUTCH DISCS
2 - USE SMALL SCREWDRIVER TO ALIGN CLUTCH DISC
TEETH
21 - 38 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)