pack JEEP GRAND CHEROKEE 2003 WJ / 2.G Repair Manual

(5) Install new seal in gear case. On 4x4 gear case,
use Tool Handle C-4171 and Installer C-3860-A to
seat seal in case. On4x2gear case, use same Han-
dle C-4171 and Installer C-3995-A to seat seal in
case.
(6) Verify that tab ends of rear bearing locating
ring extend into access hole in gear case (Fig. 175).
(7) Support geartrain on Tool 6227-1 (Fig. 176). Be
sure tool is securely seated in clutch hub.
(8) Install overdrive gear case on geartrain (Fig.
176).
(9) Expand front bearing locating ring with snap-
ring pliers (Fig. 177). Then slide case downward until
locating ring locks in bearing groove and release
snap-ring.
(10) Install locating ring access cover and gasket
in overdrive unit case (Fig. 178).
OVERDRIVE CLUTCH
(1) Install overdrive clutch reaction ring first.
Reaction ring is flat with notched ends (Fig. 179).
(2) Install wave spring on top of reaction ring (Fig.
180). Reaction ring and wave ring both fit in same
ring groove. Use screwdriver to seat each ring
securely in groove. Also ensure that the ends of the
two rings are offset from each other.
NOTE: The 42RE transmission has 3 overdrive
clutch discs and 2 plates.
(3) Assemble overdrive clutch pack (Fig. 181).
(4) Install overdrive clutch reaction plate first.
Fig. 173 Reaction Plug Locating Pin And Snap-Ring
1 - REACTION PLUG SNAP-RING (DO NOT OVERCOMPRESS
TO INSTALL)
2 - LOCATING PIN
3 - PARK LOCK REACTION PLUG
Fig. 174 Reaction Plug And Snap-Ring Installation
1 - REACTION PLUG SNAP-RING
2 - SNAP-RING PLIERS
Fig. 175 Correct Rear Bearing Locating Ring
Position
1 - CASE ACCESS HOLE
2 - TAB ENDS OF LOCATING RING
Fig. 176 Overdrive Gear Case Installation
1 - GEARTRAIN ASSEMBLY
2 - GEAR CASE
WJAUTOMATIC TRANSMISSION - 42RE 21 - 101
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)

REAR CLUTCH
DESCRIPTION
The rear clutch assembly (Fig. 224) is composed of
the rear clutch retainer, pressure plate, clutch plates,
driving discs, piston, Belleville spring, and snap-
rings. The Belleville spring acts as a lever to multi-
ply the force applied on to it by the apply piston. The
increased apply force on the rear clutch pack, in com-
parison to the front clutch pack, is needed to hold
against the greater torque load imposed onto the rear
pack. The rear clutch is directly behind the front
clutch and is considered a driving component.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
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 spring is
used to cushion the application of the clutch pack.
The snap-ring is selective and used to adjust clutch
pack clearance.
Fig. 224 Rear Clutch
1 - PISTON SPRING 10 - TOP PRESSURE PLATE
2 - REAR CLUTCH PISTON 11 - CLUTCH DISCS (4)
3 - CLUTCH PISTON SEALS 12 - BOTTOM PRESSURE PLATE
4 - OUTPUT SHAFT THRUST WASHER (METAL) 13 - WAVE SPRING
5 - INPUT SHAFT SNAP-RING 14 - CLUTCH PLATES (3)
6 - REAR CLUTCH RETAINER 15 - RETAINER SEAL RING
7 - INPUT SHAFT 16 - SHAFT REAR SEAL RING (PLASTIC)
8 - REAR CLUTCH THRUST WASHER (FIBER) 17 - SHAFT FRONT SEAL RING (TEFLON)
9 - CLUTCH PACK SNAP-RING (SELECTIVE)
21 - 118 AUTOMATIC TRANSMISSION - 42REWJ

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 pis-
ton. The check-valve is needed to eliminate the pos-
sibility of plate drag caused by centrifugal force
acting on the residual fluid trapped in the clutch pis-
ton retainer.
DISASSEMBLY
(1) Remove fiber thrust washer from forward side
of clutch retainer.
(2) Remove input shaft front/rear seal rings.
(3) Remove selective clutch pack snap-ring (Fig.
225).(4) Remove top pressure plate, clutch discs, steel
plates, bottom pressure plate and wave snap-ring
and wave spring (Fig. 225).
(5) Remove clutch piston with rotating motion.
(6) Remove and discard piston seals.
(7) Remove input shaft snap-ring (Fig. 226). It
may be necessary to press the input shaft in slightly
to relieve tension on the snap-ring
(8) Press input shaft out of retainer with shop
press and suitable size press tool. Use a suitably
sized press tool to support the retainer as close to the
input shaft as possible.CLEANING
Clean the clutch components with solvent and dry
them with compressed air. Do not use rags or shop
towels to dry any of the clutch parts. Lint from such
materials will adhere to component surfaces and
could restrict or block fluid passages after assembly.
Fig. 225 Rear Clutch Components
1 - PISTON SPRING 10 - TOP PRESSURE PLATE
2 - REAR CLUTCH PISTON 11 - CLUTCH DISCS (4)
3 - CLUTCH PISTON SEALS 12 - BOTTOM PRESSURE PLATE
4 - OUTPUT SHAFT THRUST WASHER (METAL) 13 - WAVE SPRING
5 - INPUT SHAFT SNAP-RING 14 - CLUTCH PLATES (3)
6 - REAR CLUTCH RETAINER 15 - RETAINER SEAL RING
7 - INPUT SHAFT 16 - SHAFT REAR SEAL RING (PLASTIC)
8 - REAR CLUTCH THRUST WASHER (FIBER) 17 - SHAFT FRONT SEAL RING (TEFLON)
9 - CLUTCH PACK SNAP-RING (SELECTIVE)
WJAUTOMATIC TRANSMISSION - 42RE 21 - 119
REAR CLUTCH (Continued)

INSPECTION
Replace the clutch discs if warped, worn, scored,
burned/charred, the lugs are damaged, or if the fac-
ing is flaking off. Replace the top and bottom pres-
sure plates if scored, warped, or cracked. Be sure the
driving lugs on the pressure and clutch plates are
also in good condition. The lugs must not be bent,
cracked or damaged in any way.
Replace the piston spring and wave spring if either
part is distorted, warped or broken.
Check the lug grooves in the clutch retainer. The
clutch and pressure plates should slide freely in the
slots. Replace the retainer if the grooves are worn or
damaged. Also check action of the check balls in the
retainer and piston. Each check ball must move
freely and not stick.
Replace the retainer bushing if worn, scored, or
doubt exists about bushing condition.
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.
Check condition of the fiber thrust washer and
metal output shaft thrust washer. Replace either
washer if worn or damaged.
Check condition of the seal rings on the input shaft
and clutch retainer hub. Replace the seal rings only
if worn, distorted, or damaged. The input shaft front
seal ring is teflon with chamfered ends. The rear ring
is metal with interlocking ends.
Check the input shaft for wear, or damage. Replace
the shaft if worn, scored or damaged in any way.
ASSEMBLY
(1) Soak clutch discs in transmission fluid while
assembling other clutch parts.
(2) Install new seal rings on clutch retainer hub
and input shaft, if necessary, (Fig. 227) and (Fig.
228).
(a) Be sure clutch hub seal ring is fully seated in
groove and is not twisted.
(3) Lubricate splined end of input shaft and clutch
retainer with transmission fluid. Then press input
shaft into retainer (Fig. 229). Use a suitably sized
press tool to support retainer as close to input shaft
as possible.
(4) Install input shaft snap-ring (Fig. 226).
(5) Invert retainer and press input shaft in oppo-
site direction until snap-ring is seated.
(6) Install new seals on clutch piston. Be sure lip
of each seal faces interior of clutch retainer.
(7) Lubricate lip of piston seals with generous
quantity of MopartDoor Ease. Then lubricate
retainer hub and bore with light coat of transmission
fluid.
(8) Install clutch piston in retainer. Use twisting
motion to seat piston in bottom of retainer. A thin
strip of plastic (about 0.0209thick), can be used to
guide seals into place if necessary.
CAUTION: Never push the clutch piston straight in.
This will fold the seals over causing leakage and
clutch slip. In addition, never use any type of metal
tool to help ease the piston seals into place. Metal
tools will cut, shave, or score the seals.
(9) Install piston spring in retainer and on top of
piston (Fig. 230). Concave side of spring faces down-
ward (toward piston).
(10) Install wave spring in retainer (Fig. 230). Be
sure spring is completely seated in retainer groove.
(11) Install bottom pressure plate (Fig. 225).
Ridged side of plate faces downward (toward piston)
and flat side toward clutch pack.
(12) Install first clutch disc in retainer on top of
bottom pressure plate. Then install a clutch plate fol-
lowed by a clutch disc until entire clutch pack is
installed (4 discs and 3 plates are required) (Fig.
225).
(13) Install top pressure plate.
(14) Install selective snap-ring. Be sure snap-ring
is fully seated in retainer groove.
(15) Using a suitable gauge bar and dial indicator,
measure clutch pack clearance (Fig. 231).
(a) Position gauge bar across the clutch drum
with the dial indicator pointer on the pressure
plate (Fig. 231).
(b) Using two small screw drivers, lift the pres-
sure plate and release it.
Fig. 226 Removing Input Shaft Snap-Ring
1 - REAR CLUTCH RETAINER
2 - INPUT SHAFT SNAP-RING
3 - SNAP-RING PLIERS
21 - 120 AUTOMATIC TRANSMISSION - 42REWJ
REAR CLUTCH (Continued)

The selective snap-ring thicknesses are:
²0.107-0.109 in.
²0.098-0.100 in.
²0.095-0.097 in.
²0.083-0.085 in.
²0.076-0.078 in.
²0.071-0.073 in.
²0.060-0.062 in.
(16) Coat rear clutch thrust washer with petro-
leum jelly and install washer over input shaft and
into clutch retainer (Fig. 232). Use enough petroleum
jelly to hold washer in place.REAR SERVO
DESCRIPTION
The rear (low/reverse) servo consists of a single
stage or diameter piston and a spring loaded plug.
The spring is used to cushion the application of the
rear (low/reverse) band.
OPERATION
While in the de-energized state (no pressure
applied), the piston is held up in its bore by the pis-
ton spring. The plug is held down in its bore, in the
piston, by the plug spring. When pressure is applied
to the top of the piston, the plug is forced down in its
bore, taking up any clearance. As the piston moves, it
causes the plug spring to compress, and the piston
moves down over the plug. The piston continues to
move down until it hits the shoulder of the plug and
fully applies the band. The period of time from the
initial application, until the piston is against the
shoulder of the plug, represents a reduced shocking
of the band that cushions the shift.
DISASSEMBLY
(1) Remove small snap-ring and remove plug and
spring from servo piston (Fig. 233).
(2) Remove and discard servo piston seal ring.
CLEANING
Remove and discard the servo piston seal ring (Fig.
234). Then clean the servo components with solvent
and dry with compressed air. Replace either spring if
collapsed, distorted or broken. Replace the plug and
piston if cracked, bent, or worn. Discard the servo
snap-rings and use new ones at assembly.
Fig. 231 Checking Rear Clutch Pack Clearance
1 - DIAL INDICATOR
2 - PRESSURE PLATE
3 - SNAP-RING
4-STAND
5 - REAR CLUTCH
6 - GAUGE BAR
Fig. 232 Installing Rear Clutch Thrust Washer
1 - REAR CLUTCH RETAINER
2 - REAR CLUTCH THRUST WASHER
Fig. 233 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
21 - 122 AUTOMATIC TRANSMISSION - 42REWJ
REAR CLUTCH (Continued)

INSTALLATION........................253
OUTPUT SPEED SENSOR
DESCRIPTION........................254
OPERATION..........................254
REMOVAL............................254
INSTALLATION........................254
OVERDRIVE SWITCH
DESCRIPTION........................254
OPERATION..........................254
PARK LOCK CABLE
REMOVAL............................255
INSTALLATION........................255
PISTONS
DESCRIPTION........................256
OPERATION..........................256
PLANETARY GEARTRAIN
DESCRIPTION........................258
OPERATION..........................260
DISASSEMBLY........................260
CLEANING...........................260
INSPECTION.........................260
ASSEMBLY...........................261
SHIFT MECHANISM
DESCRIPTION........................261
OPERATION..........................261
REMOVAL............................261
INSTALLATION........................263
SOLENOID SWITCH VALVE
DESCRIPTION........................263
OPERATION..........................263
SOLENOIDS
DESCRIPTION........................263OPERATION..........................264
TORQUE CONVERTER
DESCRIPTION........................264
OPERATION..........................268
REMOVAL............................269
INSTALLATION........................269
TRANSMISSION CONTROL RELAY
DESCRIPTION........................270
OPERATION..........................270
TRANSMISSION RANGE SENSOR
DESCRIPTION........................270
OPERATION..........................270
TRANSMISSION SOLENOID/TRS ASSEMBLY
DESCRIPTION........................271
OPERATION..........................271
REMOVAL............................272
INSTALLATION........................272
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION........................272
OPERATION..........................272
VALVE BODY
DESCRIPTION........................273
OPERATION..........................273
REMOVAL............................274
DISASSEMBLY........................275
CLEANING...........................277
INSPECTION.........................277
ASSEMBLY...........................278
INSTALLATION........................279
AUTOMATIC TRANSMISSION -
545RFE
DESCRIPTION
The 545RFE automatic transmission is a sophisti-
cated, multi-range, electronically controlled transmis-
sion which combines optimized gear ratios for
responsive performance, state of the art efficiency
features and low NVH. Other features include driver
adaptive shifting and three planetary gear sets to
provide wide ratio capability with precise ratio steps
for optimum driveability. The three planetary gear
sets also make available a unique alternate second
gear ratio. The primary 2nd gear ratio fits between
1st and 3rd gears for normal through-gear accelera-
tions. The alternate second gear ratio (2prime) allows
smoother 4-2 kickdowns at high speeds to provide
2nd gear passing performance over a wider highway
cruising range. An additional overdrive ratio (0.67:1)
is also provided for greater fuel economy and less
NVH at highway speeds.The hydraulic portion of the transmission consists
of the transmission fluid, fluid passages, hydraulic
valves, and various line pressure control components.
The primary mechanical components of the trans-
mission consist of the following:
²Three multiple disc input clutches
²Three multiple disc holding clutches
²Five hydraulic accumulators
²Three planetary gear sets
²Dual Stage Hydraulic oil pump
²Valve body
²Solenoid pack
The TCM is the ªheartº or ªbrainº of the electronic
control system and relies on information from vari-
ous direct and indirect inputs (sensors, switches, etc.)
to determine driver demand and vehicle operating
conditions. With this information, the TCM can cal-
culate and perform timely and quality shifts through
various output or control devices (solenoid pack,
transmission control relay, etc.).
21 - 178 AUTOMATIC TRANSMISSION - 545RFEWJ

TRANSMISSION IDENTIFICATION
Transmission identification numbers are stamped
on the left side of the case just above the oil pan
sealing surface (Fig. 1). Refer to this information
when ordering replacement parts. A label is attached
to the transmission case above the stamped numbers.
The label gives additional information which may
also be necessary for identification purposes.
GEAR RATIOS The 545RFE gear ratios are:
1st .................................3.00:1
2nd.................................1.67:1
2nd Prime............................1.50:1
3rd .................................1.00:1
4th .................................0.75:1
5th .................................0.67:1
Reverse..............................3.00:1
OPERATION
The 545RFE offers full electronic control of all auto-
matic up and downshifts, and features real-time adap-
tive closed-loop shift and pressure control. Electronic
shift and torque converter clutch controls help protect
the transmission from damage due to high tempera-
tures, which can occur under severe operating condi-
tions. By altering shift schedules, line pressure, and
converter clutch control, these controls reduce heat gen-
eration and increase transmission cooling.
To help reduce efficiency-robbing parasitic losses,
the transmission includes a dual-stage transmission
fluid pump with electronic output pressure control.
Under most driving conditions, pump output pres-
sure greatly exceeds that which is needed to keep the
clutches applied. The 545RFE pump-pressure controlsystem monitors input torque and adjusts the pump
pressure accordingly. The primary stage of the pump
works continuously; the second stage is bypassed
when demand is low. The control system also moni-
tors input and output speed and, if incipient clutch
slip is observed, the pressure control solenoid duty
cycle is varied, increasing pressure in proportion to
demand.
A high-travel torque converter damper assembly
allows earlier torque converter clutch engagement to
reduce slippage. Needle-type thrust bearings reduce
internal friction. The 545RFE is packaged in a one-
piece die-cast aluminum case. To reduce NVH, the
case has high lateral, vertical and torsional stiffness.
It is also designed to maximize the benefit of the
structural dust cover that connects the bottom of the
bell housing to the engine bedplate, enhancing over-
all power train stiffness. Dual filters protect the
pump and other components. A pump return filter is
added to the customary main sump filter. Indepen-
dent lubrication and cooler circuits assure ample
pressure for normal transmission operation even if
the cooler is obstructed or the fluid cannot flow due
to extremely low temperatures.
The hydraulic control system design (without elec-
tronic assist) provides the transmission with PARK,
REVERSE, NEUTRAL, SECOND, and THIRD gears,
based solely on driver shift lever selection. This
design allows the vehicle to be driven (in ªlimp-inº
mode) in the event of a electronic control system fail-
ure, or a situation that the Transmission Control
Module (TCM) recognizes as potentially damaging to
the transmission.
The TCM also performs certain self-diagnostic
functions and provides comprehensive information
(sensor data, DTC's, etc.) which is helpful in proper
diagnosis and repair. This information can be viewed
with the DRB scan tool.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION
CAUTION: Before attempting any repair on a
545RFE automatic transmission, check for Diagnos-
tic Trouble Codes with the DRBTscan tool.
Transmission malfunctions may be caused by these
general conditions:
²Poor engine performance
²Improper adjustments
²Hydraulic malfunctions
²Mechanical malfunctions
²Electronic malfunctions
Fig. 1 Transmission Part And Serial Number
Location
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 179
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(28) Remove the front 2C clutch pack snap-ring
from the transmission case (Fig. 24).
(29) Remove the 2C clutch pack from the transmis-
sion case (Fig. 24).
(30) Remove the rear selective plate and number 6
bearing from the reaction annulus (Fig. 25).
(31) Remove the reaction annulus from the reac-
tion planetary carrier (Fig. 25).
(32) Remove the number 7 bearing (Fig. 25).
(33) Remove the reaction sun gear (Fig. 25).
(34) Remove the number 8 bearing from the reac-
tion planetary carrier (Fig. 25).
(35) Remove the reaction planetary carrier (Fig.
25). Note that this planetary gear set has three pin-
ion gears.
(36) Remove the number 9 bearing from the
reverse planetary gear set (Fig. 25).
Fig. 24 Remove 2C Clutch Pack
1 - SNAP-RING
2 - PLATE
3 - DISC
4 - REACTION PLATE
Fig. 25 Remove Reaction Annulus and Carrier
1 - BEARING NUMBER 8 5 - BEARING NUMBER 7
2 - BEARING NUMBER 9 6 - THRUST PLATE (SELECT)
3 - REACTION PLANETARY CARRIER 7 - BEARING NUMBER 6
4 - REACTION SUN GEAR 8 - REACTION ANNULUS
21 - 188 AUTOMATIC TRANSMISSION - 545RFEWJ
AUTOMATIC TRANSMISSION - 545RFE (Continued)