2002 JEEP GRAND CHEROKEE Vin

(6) If pump seal was not removed during transmis-
sion disassembly, remove seal with punch and ham-
mer.
(7) Remove front clutch thrust washer from sup-
port hub (Fig. 114).
OIL PUMP BUSHING REPLACEMENT
(1) Remove pump bushing with Tool Handle
C-4171 and Bushing Remover SP-3551 from Tool Set
C-3887-J (Fig. 115).
(2) Install new pump bushing with Tool Handle
C-4171 and Bushing Installer SP-5117 (Fig. 115).
Bushing should be flush with pump housing bore.
(3) Stake new pump bushing in two places with
blunt punch (Fig. 116). Remove burrs from stake
points with knife blade afterward.
REACTION SHAFT SUPPORT BUSHING REMOVAL
(1) Assemble Bushing Remover Tools SP-1191,
3633 and 5324 (Fig. 117). Do not clamp any part of
reaction shaft or support in vise.
(2) Hold Cup Tool SP-3633 firmly against reaction
shaft and thread remover SP-5324 into bushing as
far as possible by hand. Then thread remover tool 3-4
additional turns into bushing with a wrench.(3) Turn remover tool hex nut down against
remover cup to pull bushing from shaft. Clean all
chips from shaft after bushing removal.
Fig. 112 Separating Pump Housing From Reaction
Shaft Support
1 - REACTION SHAFT SUPPORT
2 - PUMP HOUSING
Fig. 113 Pump Gear Removal
1 - REACTION SHAFT SUPPORT
2 - INNER GEAR
3 - OUTER GEAR
Fig. 114 Support Hub Thrust Washer
1 - BUSHING
2 - REACTION SHAFT SUPPORT
3 - THRUST WASHER
4 - HUB
Fig. 115 Removing Oil Pump Bushing
1 - SPECIAL TOOL C-4171
2 - SPECIAL TOOL SP-3551
3 - BUSHING
4 - SPECIAL TOOL SP-5117
5 - BUSHING
6 - SPECIAL TOOL C-4171
7 - PUMP HOUSING
21 - 82 AUTOMATIC TRANSMISSION - 42REWJ
OIL PUMP (Continued)

DIAGNOSIS AND TESTING - OVERDRIVE
ELECTRICAL CONTROLS
The overdrive off switch, valve body solenoid, case
connectors and related wiring can all be tested with
a 12 volt test lamp or a volt/ohmmeter. Check conti-
nuity of each component when diagnosis indicates
this is necessary.
Switch and solenoid continuity should be checked
whenever the transmission fails to shift into fourth
gear range.
OVERDRIVE UNIT
REMOVAL
(1) Shift transmission into PARK.
(2) Raise vehicle.
(3) Remove transfer case, if equipped.
(4) Mark propeller shaft universal joint(s) and axle
pinion yoke, or the companion flange and flange
yoke, for alignment reference at installation, if necc-
esary.
(5) Disconnect and remove the rear propeller shaft,
if necessary. (Refer to 3 - DIFFERENTIAL & DRIV-
ELINE/PROPELLER SHAFT/PROPELLER SHAFT -
REMOVAL)
(6) Remove transmission oil pan, remove gasket,
drain oil and reinstall pan.
(7) If overdrive unit had malfunctioned, or if fluid
is contaminated, remove entire transmission. If diag-
nosis indicated overdrive problems only, remove just
the overdrive unit.
(8) Support transmission with transmission jack.
(9) Remove bolts attaching overdrive unit to trans-
mission (Fig. 126).
CAUTION: Support the overdrive unit with a jack
before moving it rearward. This is necessary to pre-
vent damaging the intermediate shaft. Do not allow
the shaft to support the entire weight of the over-
drive unit.(10) Carefully work overdrive unit off intermediate
shaft. Do not tilt unit during removal. Keep it as
level as possible.
(11) If overdrive unit does not require service,
immediately insert Alignment Tool 6227-2 in splines
of planetary gear and overrunning clutch to prevent
splines from rotating out of alignment. If misalign-
ment occurs, overdrive unit will have to be disassem-
bled in order to realign splines.
(12) Remove and retain overdrive piston thrust
bearing. Bearing may remain on piston or in clutch
hub during removal.
(13) Position drain pan on workbench.
(14) Place overdrive unit over drain pan. Tilt unit
to drain residual fluid from case.
(15) Examine fluid for clutch material or metal
fragments. If fluid contains these items, overhaul will
be necessary.
(16) If overdrive unit does not require any service,
leave alignment tool in position. Tool will prevent
accidental misalignment of planetary gear and over-
running clutch splines.Fig. 126 Overdrive Unit Bolts
1 - OVERDRIVE UNIT
2 - ATTACHING BOLTS (7)
WJAUTOMATIC TRANSMISSION - 42RE 21 - 87
OVERDRIVE OFF SWITCH (Continued)

OVERDRIVE CLUTCH PACK
(1) Remove overdrive clutch pack wire retaining
ring (Fig. 132).
(2) Remove overdrive clutch pack (Fig. 133).
NOTE: The 42RE transmission has three clutch
discs and two clutch plates.
(3) Note position of clutch pack components for
assembly reference (Fig. 134).
Fig. 131 Overdrive Piston Removal
1 - PISTON RETAINER
2 - OVERDRIVE PISTON
Fig. 132 Removing Overdrive Clutch Pack Retaining
Ring
1 - OVERDRIVE CLUTCH PACK RETAINING RING
Fig. 133 Overdrive Clutch Pack Removal
1 - OVERDRIVE CLUTCH PACK
Fig. 134 42RE Overdrive Clutch Component
Position
1 - PRESSURE PLATE (TO FRONT)
2 - OVERDRIVE CLUTCH PACK
3 - CLUTCH DISC (3)
4 - CLUTCH PLATE (2)
5 - REACTION PLATE (TO REAR)
WJAUTOMATIC TRANSMISSION - 42RE 21 - 89
OVERDRIVE UNIT (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)

(5) Remove overrunning clutch from hub.
(6) Mark position of annulus gear and direct clutch
drum for assembly alignment reference (Fig. 149).
Use small center punch or scriber to make alignment
marks.(7) Remove direct clutch drum rear retaining ring
(Fig. 150).
(8) Remove direct clutch drum outer retaining ring
(Fig. 151).
(9) Mark annulus gear and output shaft for assem-
bly alignment reference (Fig. 152). Use punch or
scriber to mark gear and shaft.
Fig. 147 Removing Sun Gear, Thrust Bearing And
Planetary Gear
1 - PLANETARY GEAR
2 - PLANETARY THRUST BEARING
3 - CLUTCH SPRING PLATE
4 - SPRING PLATE SNAP-RING
5 - SUN GEAR
Fig. 148 Overrunning Clutch
1 - OVERRUNNING CLUTCH
2 - NEEDLE BEARING
Fig. 149 Marking Direct Clutch Drum And Annulus
Gear For Assembly Alignment
1 - DIRECT CLUTCH DRUM
2 - HAMMER
3 - PUNCH
Fig. 150 Clutch Drum Inner Retaining Ring Removal
1 - INNER RETAINING RING
2 - DIRECT CLUTCH DRUM
3 - ANNULUS GEAR
WJAUTOMATIC TRANSMISSION - 42RE 21 - 93
OVERDRIVE UNIT (Continued)

(3) Leave Alignment Tool 6227-2 in place. Tool will
keep planetary and clutch hub splines in alignment
until overdrive unit is ready for installation on trans-
mission.
(4) Transmission speed sensor can be installed at
this time if desired. However, it is recommended that
sensor not be installed until after overdrive unit is
secured to transmission.
OVERDRIVE PISTON
(1) Install new seals on over drive piston.
(2) Stand transmission case upright on bellhous-
ing.
(3) Position Guide Ring 8114-1 on outer edge of
overdrive piston retainer.
(4) Position Seal Guide 8114-2 on inner edge of
overdrive piston retainer.
(5) Install overdrive piston in overdrive piston
retainer by: aligning locating lugs on overdrive piston
to the two mating holes in retainer.
(a) Aligning locating lugs on overdrive piston to
the two mating holes in retainer.(b) Lubricate overdrive piston seals with Mopart
Door Ease, or equivalent.
(c) Install piston over Seal Guide 8114-2 and
inside Guide Ring 8114-1.
(d) Push overdrive piston into position in
retainer.
(e) Verify that the locating lugs entered the lug
bores in the retainer.
(6) Install intermediate shaft spacer on intermedi-
ate shaft.
(7) Install overdrive piston thrust plate on over-
drive piston.
(8) Install overdrive piston thrust bearing on over-
drive piston.
(9) Install transmission speed sensor and O-ring
seal in overdrive case (Fig. 127).
INSTALLATION
(1) Be sure overdrive unit Alignment Tool 6227-2
is fully seated before moving unit. If tool is not
seated and gear splines rotate out of alignment, over-
drive unit will have to be disassembled in order to
realign splines.
(2) If overdrive piston retainer was not removed
during service and original case gasket is no longer
reusable, prepare new gasket by trimming it.
(3) Cut out old case gasket around piston retainer
with razor knife (Fig. 187).
(4) Use old gasket as template and trim new gas-
ket to fit.
(5) Position new gasket over piston retainer and
on transmission case. Use petroleum jelly to hold
gasket in place if necessary. Do not use any type of
sealer to secure gasket. Use petroleum jelly only.
(6) Install selective spacer on intermediate shaft, if
removed. Spacer goes in groove just rearward of
shaft rear splines (Fig. 188).
(7) Install thrust bearing in overdrive unit sliding
hub. Use petroleum jelly to hold bearing in position.
Fig. 184 Intermediate Shaft End Play Spacer
Selection
Fig. 185 Overdrive Piston Thrust Plate Measurement
1 - SPECIAL TOOL 6311
2 - DIRECT CLUTCH HUB THRUST BEARING SEAT
3 - SPECIAL TOOL C-4962
Fig. 186 Overdrive Piston Thrust Plate Selection
21 - 104 AUTOMATIC TRANSMISSION - 42REWJ
OVERDRIVE UNIT (Continued)

PLANETARY GEARTRAIN/
OUTPUT SHAFT
DESCRIPTION
The planetary gearsets (Fig. 203) are designated as
the front, rear, and overdrive planetary gear assem-
blies and located in such order. A simple planetary
gearset consists of three main members:
²The sun gear which is at the center of the sys-
tem.
²The planet carrier with planet pinion gears
which are free to rotate on their own shafts and are
in mesh with the sun gear.
²The annulus gear, which rotates around and is
in mesh with the planet pinion gears.
NOTE: The number of pinion gears does not affect
the gear ratio, only the duty rating.
OPERATION
With any given planetary gearset, several condi-
tions must be met for power to be able to flow:
²One member must be held.
²Another member must be driven or used as an
input.
²The third member may be used as an output for
power flow.
²For direct drive to occur, two gear members in
the front planetary gearset must be driven.
NOTE: Gear ratios are dependent on the number of
teeth on the annulus and sun gears.
DISASSEMBLY
(1) Remove planetary snap-ring (Fig. 204).
(2) Remove front annulus and planetary assembly
from driving shell (Fig. 204).
(3) Remove snap-ring that retains front planetary
gear in annulus gear (Fig. 205).
(4) Remove tabbed thrust washer and tabbed
thrust plate from hub of front annulus (Fig. 206).
(5) Separate front annulus and planetary gears
(Fig. 206).
(6) Remove front planetary gear front thrust
washer from annulus gear hub.
(7) Separate and remove driving shell, rear plane-
tary and rear annulus from output shaft (Fig. 207).
(8) Remove front planetary rear thrust washer
from driving shell.
(9) Remove tabbed thrust washers from rear plan-
etary gear.
(10) Remove lock ring that retains sun gear in
driving shell. Then remove sun gear, spacer and
thrust plates.
Fig. 203 Planetary Gearset
1 - ANNULUS GEAR
2 - SUN GEAR
3 - PLANET CARRIER
4 - PLANET PINIONS (4)
Fig. 204 Front Annulus And Planetary Assembly
Removal
1 - DRIVING SHELL
2 - FRONT ANNULUS AND PLANETARY ASSEMBLY
3 - PLANETARY SNAP-RING
Fig. 205 Front Planetary Snap-Ring Removal
1 - FRONT ANNULUS GEAR
2 - PLANETARY SNAP-RING
21 - 112 AUTOMATIC TRANSMISSION - 42REWJ

INSPECTION
Check sun gear and driving shell condition.
Replace the gear if damaged or if the bushings are
scored or worn. The bushings are not serviceable.
Replace the driving shell if worn, cracked or dam-
aged.Replace planetary gear sets if gears, pinion pins, or
carrier are damaged in any way. Replace the annulus
gears and supports if either component is worn or
damaged.
Inspect the geartrain spacers, thrust plates, snap-
rings, and thrust washers. Replace any of these parts
that are worn, distorted or damaged. Do not attempt
to reuse these parts.
The planetary gear thrust washers are different
sizes. The large diameter washers go on the front
planetary and the smaller washers go on the rear
planetary. All the washers have four locating tabs on
them. These tabs fit in the holes or slots provided in
each planetary gear.
Inspect the output shaft carefully. Pay particular
attention to the machined bushing/bearing surfaces
on the shaft and the governor valve shaft bore at the
shaft rear.
Replace the output shaft if the machined surfaces
are scored, pitted, or damaged in any way. Also
replace the shaft if the splines are damaged, or
exhibits cracks at any location (especially at the gov-
ernor valve shaft bore).
The annulus gears can be removed from their sup-
ports if necessary. Just remove the snap-rings and
separate the two parts when replacement is neces-
sary. In addition, the annulus gear bushings can be
replaced if severely worn, or scored. However it is not
necessary to replace the bushings if they only exhibit
normal wear. Check bushing fit on the output shaft
to be sure.
ASSEMBLY
(1) Lubricate output shaft and planetary compo-
nents with transmission fluid. Use petroleum jelly to
lubricate and hold thrust washers and plates in posi-
tion.
(2) Assemble rear annulus gear and support if dis-
assembled. Be sure support snap-ring is seated and
that shoulder-side of support faces rearward (Fig.
208).
(3) Install rear thrust washer on rear planetary
gear. Use enough petroleum jelly to hold washer in
place. Also be sure all four washer tabs are properly
engaged in gear slots.
(4) Install rear annulus over and onto rear plane-
tary gear (Fig. 208).
(5) Install assembled rear planetary and annulus
gear on output shaft (Fig. 209). Verify that assembly
is fully seated on shaft.
Fig. 206 Front Planetary And Annulus Gear
Disassembly
1 - FRONT ANNULUS
2 - THRUST WASHER
3 - THRUST PLATE
4 - FRONT THRUST WASHER
5 - FRONT PLANETARY
Fig. 207 Removing Driving Shell, Rear Planetary
And Rear Annulus
1 - REAR ANNULUS
2 - REAR PLANETARY
3 - DRIVING SHELL
4 - OUTPUT SHAFT
WJAUTOMATIC TRANSMISSION - 42RE 21 - 113
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)