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

(8) Install new seals on over drive piston.
(9) Stand transmission case upright on bellhous-
ing.
(10) Position Guide Ring 8114-1 on outer edge of
overdrive piston retainer.
(11) Position Seal Guide 8114-2 on inner edge of
overdrive piston retainer.
(12) 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.
NOTE: Install the remaining transmission compo-
nents and the overdrive unit.
PARK LOCK CABLE
REMOVAL
(1) Place the shifter in the PARK position.
(2) Lower the steering column cover.
(3) With the ignition switch in the ªRUNº position
depress the park lock cable locking tab, located on
top of the cable connector at the steering column and
pull the park lock cable straight out.
(4) Remove the park lock cable from steering col-
umn (Fig. 197).
(5) Remove the floor console and related trim.
(Refer to 23 - BODY/INTERIOR/FLOOR CONSOLE -
REMOVAL)
(6) Disconnect the park lock cable from the shift
BTSI lever and remove the cable from the shifter
assembly bracket.
(7) Release the park lock cable from any remaining
clips.
(8) Remove park lock cable from the vehicle.
INSTALLATION
NOTE: The gearshift cable must be secured into
position and properly adjusted before the installa-
tion of the Park Lock Cable.
(1) Verify that the shifter is in the PARK position.
(2) Push the park lock cable straight into the
square mounting hole in the steering column until
cable snaps in place.
(3) Route park lock cable to the shifter mecha-
nism.
(4) Install the park lock cable end fitting into
shifter BTSI lever.
(5) Pull rearward on the cable housing to snap
park lock cable adjuster ears into floor shifter
bracket.
(6) Place the ignition key cylinder in the ACCES-
SORY position.
(7) Push the cable adjuster lock clamp downward
to lock it.
(8) Test the park lock cable operation.
(9) Install the floor console and related trim.
(Refer to 23 - BODY/INTERIOR/FLOOR CONSOLE -
INSTALLATION)
Fig. 196 Aligning Overdrive Piston Retainer
1 - PISTON RETAINER
2 - GASKET
3 - RETAINER BOLTS
21 - 108 AUTOMATIC TRANSMISSION - 42REWJ
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)

PARK/NEUTRAL POSITION
SWITCH
DIAGNOSIS AND TESTING - PARK/NEUTRAL
POSITION SWITCH
The center terminal of the park/neutral position
switch is the starter-circuit terminal. It provides the
ground for the starter solenoid circuit through the
selector lever in PARK and NEUTRAL positions only.
The outer terminals on the switch are for the backup
lamp circuit.
SWITCH TEST
To test the switch, remove the wiring connector.
Test for continuity between the center terminal and
the transmission case. Continuity should exist only
when the transmission is in PARK or NEUTRAL.Shift the transmission into REVERSE and test
continuity at the switch outer terminals. Continuity
should exist only when the transmission is in
REVERSE. Continuity should not exist between the
outer terminals and the case.
Check gearshift linkage adjustment before replac-
ing a switch that tests faulty.
REMOVAL
(1) Raise vehicle and position drain pan under
switch.
(2) Disconnect switch wires.
(3) Remove switch from case.
INSTALLATION
(1) Move shift lever to PARK and NEUTRAL posi-
tions. Verify that switch operating lever fingers are
centered in switch opening in case (Fig. 198).
Fig. 197 Brake Transmission Shift Interlock
1 - SHIFT MECHANISM 4 - STEERING COLUMN ASSEMBLY
2 - SHIFTER BTSI LEVER 5 - INTERLOCK CABLE
3 - ADJUSTMENT CLIP
WJAUTOMATIC TRANSMISSION - 42RE 21 - 109
PARK LOCK CABLE (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)

(6) Install front thrust washer on rear planetary
gear (Fig. 210). Use enough petroleum jelly to hold
washer on gear. Be sure all four washer tabs are
seated in slots.
(7) Install spacer on sun gear (Fig. 211).
(8) Install thrust plate on sun gear (Fig. 212). Note
that driving shell thrust plates are interchangeable.
Use either plate on sun gear and at front/rear of
shell.
(9) Hold sun gear in place and install thrust plate
over sun gear at rear of driving shell (Fig. 213).
(10) Position wood block on bench and support sun
gear on block (Fig. 214). This makes it easier to align
and install sun gear lock ring. Keep wood block
handy as it will also be used for geartrain end play
check.
Fig. 208 Assembling Rear Annulus And Planetary
Gear
1 - REAR ANNULUS GEAR
2 - TABBED THRUST WASHER
3 - REAR PLANETARY
Fig. 209 Installing Rear Annulus And Planetary On
Output Shaft
1 - REAR ANNULUS AND PLANETARY GEAR ASSEMBLY
2 - OUTPUT SHAFT
Fig. 210 Installing Rear Planetary Front Thrust
Washer
1 - FRONT TABBED THRUST WASHER
2 - REAR PLANETARY GEAR
Fig. 211 Installing Spacer On Sun Gear
1 - SUN GEAR
2 - SUN GEAR SPACER
21 - 114 AUTOMATIC TRANSMISSION - 42REWJ
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

(11) Align rear thrust plate on driving shell and
install sun gear lock ring. Be sure ring is fully seated
in sun gear ring groove (Fig. 215).
(12) Install assembled driving shell and sun gear
on output shaft (Fig. 216).
(13) Install rear thrust washer on front planetary
gear (Fig. 217). Use enough petroleum jelly to hold
washer in place and be sure all four washer tabs are
seated.
Fig. 212 Installing Driving Shell Front Thrust Plate
On Sun Gear
1 - SPACER
2 - SUN GEAR
3 - THRUST PLATE
Fig. 213 Installing Driving Shell Rear Thrust Plate
1 - DRIVING SHELL
2 - SUN GEAR
3 - REAR THRUST PLATE
Fig. 214 Supporting Sun Gear On Wood Block
1 - SUN GEAR
2 - DRIVING SHELL
3 - WOOD BLOCK
Fig. 215 Installing Sun Gear Lock Ring
1 - LOCK RING GROOVE
2 - SUN GEAR LOCK RING
3 - DRIVING SHELL
4 - REAR THRUST PLATE
WJAUTOMATIC TRANSMISSION - 42RE 21 - 115
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

(14) Install front planetary gear on output shaft
and in driving shell (Fig. 218).
(15) Install front thrust washer on front planetary
gear. Use enough petroleum jelly to hold washer in
place and be sure all four washer tabs are seated.
(16) Assemble front annulus gear and support, if
necessary. Be sure support snap-ring is seated.(17) Install front annulus on front planetary (Fig.
218).
(18) Position thrust plate on front annulus gear
support (Fig. 219). Note that plate has two tabs on it.
These tabs fit in notches of annulus hub.
(19) Install thrust washer in front annulus (Fig.
220). Align flat on washer with flat on planetary hub.
Also be sure washer tab is facing up.
(20) Install front annulus snap-ring (Fig. 221). Use
snap-ring pliers to avoid distorting ring during
installation. Also be sure ring is fully seated.
(21) Install planetary selective snap-ring with
snap-ring pliers (Fig. 222). Be sure ring is fully
seated.
(22) Turn planetary geartrain assembly over so
driving shell is facing workbench. Then support
geartrain on wood block positioned under forward
end of output shaft. This allows geartrain compo-
nents to move forward for accurate end play check.
(23) Check planetary geartrain end play with
feeler gauge (Fig. 223). Gauge goes between shoulder
on output shaft and end of rear annulus support.
(24) Geartrain end play should be 0.12 to 1.22 mm
(0.005 to 0.048 in.). If end play is incorrect, snap-ring
(or thrust washers) may have to be replaced. Snap-
rings are available in three different thicknesses for
adjustment purposes.
Fig. 216 Installing Assembled Sun Gear And Driving
Shell On Output Shaft
1 - SUN GEAR/DRIVING SHELL ASSEMBLY
2 - OUTPUT SHAFT
Fig. 217 Installing Rear Thrust Washer On Front
Planetary Gear
1 - FRONT PLANETARY GEAR
2 - REAR TABBED THRUST WASHER
Fig. 218 Installing Front Planetary And Annulus
Gears
1 - FRONT PLANETARY GEAR
2 - FRONT THRUST WASHER
3 - FRONT ANNULUS GEAR
21 - 116 AUTOMATIC TRANSMISSION - 42REWJ
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

Fig. 219 Positioning Thrust Plate On Front Annulus
Support
1 - FRONT ANNULUS
2 - THRUST PLATE
Fig. 220 Installing Front Annulus Thrust Washer
1 - WASHER FLAT ALIGNS WITH FLAT ON PLANETARY HUB
2 - FRONT ANNULUS THRUST WASHER
3 - TAB FACES FRONT
Fig. 221 Installing Front Annulus Snap-Ring
1 - SNAP-RING PLIERS
2 - FRONT ANNULUS SNAP-RING
Fig. 222 Installing Planetary Selective Snap-Ring
1 - SELECTIVE SNAP-RING
2 - SNAP-RING PLIERS
Fig. 223 Checking Planetary Geartrain End Play
1 - OUTPUT SHAFT
2 - REAR ANNULUS GEAR
3 - FEELER GAUGE
WJAUTOMATIC TRANSMISSION - 42RE 21 - 117
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

ASSEMBLY
(1) Lubricate piston and guide seals (Fig. 235)
with petroleum jelly. Lubricate other servo parts with
MopartATF +4, type 9602, transmission fluid.
(2) Install new seal ring on servo piston.
(3) Assemble piston, plug, spring and new snap-
ring.
(4) Lubricate piston seal lip with petroleum jelly.
SHIFT MECHANISM
DESCRIPTION
The gear shift mechanism provides six shift posi-
tions which are:
²PARK (P)
²REVERSE (R)
²NEUTRAL (N)
²DRIVE (D)
²Manual SECOND (2)
²Manual LOW (1)
OPERATION
Manual LOW (1) range provides first gear only.
Overrun braking is also provided in this range. Man-
ual SECOND (2) range provides first and second gear
only.
DRIVE range provides first, second third and over-
drive fourth gear ranges. The shift into overdrive
fourth gear range occurs only after the transmission
has completed the shift into D third gear range. No
further movement of the shift mechanism is required
to complete the 3-4 shift.
The fourth gear upshift occurs automatically when
the overdrive selector switch is in the ON position.
No upshift to fourth gear will occur if any of the fol-
lowing are true:
²The transmission fluid temperature is below 10É
C (50É F) or above 121É C (250É F).
²The shift to third is not yet complete.
²Vehicle speed is too low for the 3-4 shift to occur.
²Battery temperature is below -5É C (23É F).
REMOVAL
(1) Remove any necessary console parts for access
to shift lever assembly and shifter cables. (Refer to
23 - BODY/INTERIOR/FLOOR CONSOLE -
REMOVAL)
(2) Shift transmission into PARK.
(3) Disconnect the transmission shift cable at shift
lever and shifter assembly bracket (Fig. 236).
(4) Disconnect the park lock cable from the shifter
BTSI lever and the shifter assembly bracket. (Fig.
237)
(5) Disconnect the transfer case shift cable from
the transfer case shift lever pin (Fig. 238), if
equipped.
(6) Remove the clip holding the transfer case shift
cable to the shifter assembly bracket, if equipped.
(7) Remove the transfer case shift cable from the
shifter assembly bracket, if equipped.
Fig. 234 Rear Servo Components
1 - SNAP-RING
2 - PISTON SEAL
3 - PISTON PLUG
4 - SPRING RETAINER
5 - SNAP-RING
6 - PISTON SPRING
7 - CUSHION SPRING
8 - PISTON
Fig. 235 Rear Servo Components
1 - SNAP-RING
2 - PISTON SEAL
3 - PISTON PLUG
4 - SPRING RETAINER
5 - SNAP-RING
6 - PISTON SPRING
7 - CUSHION SPRING
8 - PISTON
WJAUTOMATIC TRANSMISSION - 42RE 21 - 123
REAR SERVO (Continued)

A solenoid can also be described by the method by
which it is controlled. Some of the possibilities
include variable force, pulse-width modulated, con-
stant ON, or duty cycle. The variable force and pulse-
width modulated versions utilize similar methods to
control the current flow through the solenoid to posi-
tion the solenoid plunger at a desired position some-
where between full ON and full OFF. The constant
ON and duty cycled versions control the voltage
across the solenoid to allow either full flow or no flow
through the solenoid's valve.
OPERATION
When an electrical current is applied to the sole-
noid coil, a magnetic field is created which produces
an attraction to the plunger, causing the plunger to
move and work against the spring pressure and the
load applied by the fluid the valve is controlling. The
plunger is normally directly attached to the valve
which it is to operate. When the current is removed
from the coil, the attraction is removed and the
plunger will return to its original position due to
spring pressure.
The plunger is made of a conductive material and
accomplishes this movement by providing a path for
the magnetic field to flow. By keeping the air gap
between the plunger and the coil to the minimum
necessary to allow free movement of the plunger, the
magnetic field is maximized.
SPEED SENSOR
DESCRIPTION
The speed sensor (Fig. 240) is located in the over-
drive gear case. The sensor is positioned over the
park gear and monitors transmission output shaft
rotating speed.
OPERATION
Speed sensor signals are triggered by the park
gear lugs as they rotate past the sensor pickup face.
Input signals from the sensor are sent to the trans-
mission control module for processing. Signals from
this sensor are shared with the powertrain control
module.
THROTTLE VALVE CABLE
DESCRIPTION
Transmission throttle valve cable adjustment is
extremely important to proper operation. This adjust-
ment positions the throttle valve, which controls shift
speed, quality, and part-throttle downshift sensitivity.
If cable setting is too loose, early shifts and slip-
page between shifts may occur. If the setting is too
tight, shifts may be delayed and part throttle down-
shifts may be very sensitive.
The transmission throttle valve is operated by a
cam on the throttle lever. The throttle lever is oper-
ated by an adjustable cable (Fig. 241). The cable is
attached to an arm mounted on the throttle lever
shaft. A retaining clip at the engine-end of the cable
is removed to provide for cable adjustment. The
retaining clip is then installed back onto the throttle
valve cable to lock in the adjustment.
ADJUSTMENTS - TRANSMISSION THROTTLE
VALVE CABLE
A correctly adjusted throttle valve cable (Fig. 242)
will cause the throttle lever on the transmission to
move simultaneously with the throttle body lever
from the idle position. Proper adjustment will allow
Fig. 240 Transmission Output Speed Sensor
1 - TRANSMISSION OUTPUT SHAFT SPEED SENSOR
2 - SEAL
Fig. 241 Throttle Valve Cable
1 - THROTTLE VALVE CABLE
2 - THROTTLE VALVE LEVER
3 - THROTTLE BODY
21 - 126 AUTOMATIC TRANSMISSION - 42REWJ
SOLENOID (Continued)