2003 JEEP GRAND CHEROKEE transmission mount

(8) Engine starts must be possible with shifter
lever in PARK or NEUTRAL gate positions only.
Engine starts must not be possible in any other gate
positions other than PARK or NEUTRAL.
(9) With shifter lever handle push-button not
depressed and lever detent in:
²PARK position- apply forward force on center of
handle and remove pressure. Engine start must be
possible.
²PARK position- apply rearward force on center
of handle and remove pressure. Engine start must be
possible.
²NEUTRAL position- engine start must be possi-
ble.
²NEUTRAL position, engine running and brakes
applied- Apply forward force on center of shift han-
dle. Transmission should not be able to shift into
REVERSE detent.
ELECTRONIC GOVERNOR
DESCRIPTION
Governor pressure is controlled electronically. Com-
ponents used for governor pressure control include:
²Governor body
²Valve body transfer plate
²Governor pressure solenoid valve
²Governor pressure sensor
²Fluid temperature thermistor
²Throttle position sensor (TPS)
²Transmission speed sensor
²Powertrain control module (PCM)
GOVERNOR PRESSURE SOLENOID VALVE
The solenoid valve is a duty-cycle solenoid which
regulates the governor pressure needed for upshifts
and downshifts. It is an electro-hydraulic device
located in the governor body on the valve body trans-
fer plate (Fig. 73).
GOVERNOR PRESSURE SENSOR
The governor pressure sensor measures output
pressure of the governor pressure solenoid valve (Fig.
74).
GOVERNOR BODY AND TRANSFER PLATE
The transfer plate is designed to supply transmis-
sion line pressure to the governor pressure solenoid
valve and to return governor pressure.
The governor pressure solenoid valve is mounted in
the governor body. The body is bolted to the lower
side of the transfer plate (Fig. 74).
GOVERNOR PRESSURE CURVES
There are four governor pressure curves pro-
grammed into the transmission control module. The
different curves allow the control module to adjust
governor pressure for varying conditions. One curve
is used for operation when fluid temperature is at, or
below, ±1ÉC (30ÉF). A second curve is used when fluid
temperature is at, or above, 10ÉC (50ÉF) during nor-
mal city or highway driving. A third curve is used
during wide-open throttle operation. The fourth curve
is used when driving with the transfer case in low
range.
OPERATION
Compensation is required for performance varia-
tions of two of the input devices. Though the slope of
the transfer functions is tightly controlled, offset may
vary due to various environmental factors or manu-
facturing tolerances.
The pressure transducer is affected by barometric
pressure as well as temperature. Calibration of the
zero pressure offset is required to compensate for
shifting output due to these factors.
Fig. 73 Governor Pressure Solenoid Valve
1 - SOLENOID FILTER
2 - GOVERNOR PRESSURE SOLENOID
Fig. 74 Governor Pressure Sensor
1 - GOVERNOR BODY
2 - GOVERNOR PRESSURE SENSOR/TRANSMISSION FLUID
TEMPERATURE THERMISTOR
WJAUTOMATIC TRANSMISSION - 42RE 21 - 65
BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM (Continued)

FRONT SERVO
DESCRIPTION
The kickdown servo (Fig. 98) consists of a two-land
piston with an inner piston, a piston rod and guide,
and a return spring. The dual-land piston uses seal
rings on its outer diameters and an O-ring for the
inner piston.
OPERATION
The application of the piston is accomplished by
applying pressure between the two lands of the pis-
ton. The pressure acts against the larger lower land
to push the piston downward, allowing the piston rod
to extend though its guide against the apply lever.
Release of the servo at the 2-3 upshift is accom-
plished by a combination of spring and line pressure,
acting on the bottom of the larger land of the piston.
The small piston is used to cushion the application of
the band by bleeding oil through a small orifice in
the larger piston. The release timing of the kickdown
servo is very important to obtain a smooth but firm
shift. The release has to be very quick, just as the
front clutch application is taking place. Otherwise,
engine runaway or a shift hesitation will occur. To
accomplish this, the band retains its holding capacity
until the front clutch is applied, giving a small
amount of overlap between them.
DISASSEMBLY
(1) Remove seal ring from rod guide (Fig. 99).(2) Remove small snap-ring from servo piston rod.
Then remove piston rod, spring and washer from pis-
ton.
(3) Remove and discard servo component o-ring
and seal rings.
CLEANING
Clean the servo piston components (Fig. 100) with
solvent and dry them with compressed air.
INSPECTION
Inspect the servo components (Fig. 101). Replace
the springs if collapsed, distorted or broken. Replace
the guide, rod and piston if cracked, bent, or worn.
Discard the servo snap-ring if distorted or warped.
Check the servo piston bore for wear. If the bore is
severely scored, or damaged, it will be necessary to
replace the case.
Replace any servo component if doubt exists about
condition. Do not reuse suspect parts.
ASSEMBLY
Clean and inspect front servo components.
(1) Lubricate new o-ring and seal rings with petro-
leum jelly and install them on piston, guide and rod.
(2) Install rod in piston. Install spring and washer
on rod. Compress spring and install snap-ring (Fig.
102).
Fig. 98 Front Servo
1 - VENT
2 -PISTON ROD
3 - PISTON
4 - SPRING
5 - RELEASE PRESSURE
6 - APPLY PRESSURE
Fig. 99 Front Servo
1 - PISTON RINGS
2 - O-RING
3 - SNAP-RING
4 - SEAL RING
5 - PISTON ROD GUIDE
6 - SNAP-RING
7 - SERVO SPRING
8 - PISTON ROD
9 - SERVO PISTON
WJAUTOMATIC TRANSMISSION - 42RE 21 - 77

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)

(4) Align and install clutch drum on annulus gear
(Fig. 157). Be sure drum is engaged in annulus gear
lugs.
(5) Install clutch drum outer retaining ring (Fig.
157).
(6) Slide clutch drum forward and install inner
retaining ring (Fig. 158).
(7) Install rear bearing and snap-ring on output
shaft (Fig. 159). Be sure locating ring groove in bear-
ing is toward rear.(8) Install overrunning clutch on hub (Fig. 160).
Note that clutch only fits one-way. Shoulder on clutch
should seat in small recess at edge of hub.
(9) Install thrust bearing on overrunning clutch
hub. Use generous amount of petroleum jelly to hold
bearing in place for installation. Bearing fits one-way
only. Be sure bearing is seated squarely against hub.
Reinstall bearing if it does not seat squarely.
(10) Install overrunning clutch in output shaft
(Fig. 161). Insert snap-ring pliers in hub splines.
Expand pliers to grip hub. Then install assembly
with counterclockwise, twisting motion.
(11) Install planetary gear in annulus gear (Fig.
162). Be sure planetary pinions are fully seated in
annulus gear before proceeding.
(12) Coat planetary thrust bearing and bearing
contact surface of spring plate with generous amount
of petroleum jelly. This will help hold bearing in
place during installation.
Fig. 156 Annulus Gear Installation
1 - SNAP-RING
2 - OUTPUT SHAFT FRONT BEARING
3 - ANNULUS GEAR
Fig. 157 Clutch Drum And Outer Retaining Ring
Installation
1 - ANNULUS GEAR
2 - OUTER SNAP-RING
3 - CLUTCH DRUM
Fig. 158 Clutch Drum Inner Retaining Ring
Installation
1 - ANNULUS GEAR
2 - INNER SNAP-RING
3 - CLUTCH DRUM
Fig. 159 Rear Bearing And Snap-Ring Installation
1 - REAR BEARING
2 - SNAP-RING
21 - 96 AUTOMATIC TRANSMISSION - 42REWJ
OVERDRIVE UNIT (Continued)

(15) Mount assembled output shaft, annulus gear,
and clutch drum in shop press. Direct clutch spring,
hub and clutch pack are easier to install with assem-
bly mounted in press.
(16) Align splines in hubs of planetary gear and
overrunning clutch with Alignment tool 6227-2 (Fig.
165). Insert tool through sun gear and into splines of
both hubs. Be sure alignment tool is fully seated
before proceeding.
(17) Install direct clutch spring (Fig. 166). Be sure
spring is properly seated on spring plate.
NOTE: The 42RE transmission has 6 direct clutch
discs and 5 clutch plates.
(18) Assemble and install direct clutch pack on
hub as follows:
(a) Assemble clutch pack components (Fig. 167).
(b) Install direct clutch reaction plate on clutch
hub first. Note that one side of reaction plate is
counterbored. Be sure this side faces rearward.
Splines at rear of hub are raised slightly. Counter-
bore in plate fits over raised splines. Plate should
be flush with this end of hub (Fig. 168).
(c) Install first clutch disc followed by a steel
plate until all discs and plates have been installed.
(d) Install pressure plate. This is last clutch
pack item to be installed. Be sure plate is installed
with shoulder side facing upward (Fig. 169).
(19) Install clutch hub and clutch pack on direct
clutch spring (Fig. 170). Be sure hub is started on
sun gear splines before proceeding.
Fig. 164 Sun Gear Installation
1 - SUN GEAR AND SPRING PLATE ASSEMBLY
Fig. 165 Alignment Tool Installation
1 - SPECIAL TOOL 6227-2
2 - PRESS PLATES
3 - ASSEMBLED DRUM AND ANNULUS GEAR
4 - SUN GEAR
Fig. 166 Direct Clutch Spring Installation
1 - SPECIAL TOOL 6227-2
2 - DIRECT CLUTCH SPRING
3 - CLUTCH HUB
4 - PRESS PLATES
21 - 98 AUTOMATIC TRANSMISSION - 42REWJ
OVERDRIVE UNIT (Continued)

NOTE: The reaction plate is thinner than the pres-
sure plate in a 42RE transmission.
(5) Install first clutch disc followed by first clutch
plate. Then install remaining clutch discs and plates
in same order.
(6) Install clutch pack pressure plate.
(7) Install clutch pack wire-type retaining ring
(Fig. 182).
INTERMEDIATE SHAFT SPACER SELECTION
(1) Place overdrive unit in vertical position. Mount
it on blocks, or in workbench with appropriate size
mounting hole cut into it. Be sure unit is facing
upward for access to direct clutch hub. Also be sure
output shaft is not loaded and internal components
are moved rearward for accurate measurement.
(2) Determine correct thickness intermediate shaft
spacer as follows:
(a) Insert Special Tool 6312 through sun gear,
planetary gear and into pilot bushing in output
shaft. Be sure tool bottoms against planetary
shoulder.
(b) Position Gauge Tool 6311 across face of over-
drive case (Fig. 183). Then position Dial Caliper
C-4962 over gauge tool.
(c) Extend sliding scale of dial caliper downward
through gauge tool slot until scale contacts end of
Gauge Alignment Tool 6312. Lock scale in place.
Remove dial caliper tool and note distance mea-
sured (Fig. 183).
(d) Select proper thickness end play spacer from
spacer chart based on distance measured (Fig.
184).
(e) Remove Gauge Alignment Tool 6312.
Fig. 177 Seating Locating Ring In Rear Bearing
1 - EXPAND BEARING LOCATING RING WITH SNAP-RING
PLIERS
2 - ACCESS HOLE
Fig. 178 Locating Ring Access Cover And Gasket
Installation
1 - TORX SCREWDRIVER (T25)
2 - ACCESS COVER SCREWS
Fig. 179 Overdrive Clutch Reaction Ring Installation
1 - REACTION RING
2 - CLUTCH HUB
Fig. 180 Overdrive Clutch Wave Spring Installation
1 - WAVE SPRING
21 - 102 AUTOMATIC TRANSMISSION - 42REWJ
OVERDRIVE UNIT (Continued)

OD THRUST PLATE SELECTION
(1) Place overdrive unit in vertical position. Mount
it on blocks, or in workbench with appropriate size
mounting hole cut into it. Be sure unit is facing
upward for access to direct clutch hub. Also be sure
output shaft is not loaded and internal components
are moved rearward for accurate measurement.
(2) Determine correct thickness overdrive piston
thrust plate as follows:(a) Position Gauge Tool 6311 across face of over-
drive case. Then position Dial Caliper C-4962 over
gauge tool (Fig. 185).
(b) Measure distance to clutch hub thrust bear-
ing seat at four points 90É apart. Then average
measurements by adding them and dividing by 4.
(c) Select and install required thrust plate from
information in thrust plate chart (Fig. 186).
Fig. 181 42RE Overdrive Clutch Components
1 - REACTION PLATE 2 - PRESSURE PLATE
Fig. 182 Overdrive Clutch Pack Retaining Ring
Installation
1 - OVERDRIVE CLUTCH PACK RETAINING RING
Fig. 183 Shaft End Play Measurement
1 - SPECIAL TOOL 6312
2 - SPECIAL TOOL 6311
3 - SPECIAL TOOL C-4962
WJAUTOMATIC TRANSMISSION - 42RE 21 - 103
OVERDRIVE UNIT (Continued)

(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)