2003 JEEP GRAND CHEROKEE prop shaft

DIAGNOSIS CHARTS
CONDITION POSSIBLE CAUSES CORRECTION
HARSH
ENGAGEMENT
(FROM NEUTRAL TO
DRIVE OR REVERSE)1. Fluid Level Low. 1. Add Fluid
2. Throttle Linkage Mis-adjusted. 2. Adjust linkage - setting may be too long.
3. Mount and Driveline Bolts
Loose.3. Check engine mount, transmission mount,
propeller shaft, rear spring to body bolts, rear
control arms, crossmember and axle bolt torque.
Tighten loose bolts and replace missing bolts.
4. U-Joint Worn/Broken. 4. Remove propeller shaft and replace U-Joint.
5. Axle Backlash Incorrect. 5. Check per Service Manual. Correct as needed.
6. Hydraulic Pressure Incorrect. 6. Check pressure. Remove, overhaul or adjust
valve body as needed.
7. Band Mis-adjusted. 7. Adjust rear band.
8. Valve Body Check Balls Missing. 8. Inspect valve body for proper check ball
installation.
9. Axle Pinion Flange Loose. 9. Replace nut and check pinion threads before
installing new nut. Replace pinion gear if threads
are damaged.
10. Clutch, band or planetary
component damaged.10. Remove, disassemble and repair transmission
as necessary.
11. Converter Clutch Faulty. 11. Replace converter and flush cooler and line
before installing new converter.
DELAYED
ENGAGEMENT
(FROM NEUTRAL TO
DRIVE OR REVERSE)1. Fluid Level Low. 1. Correct level and check for leaks.
2. Filter Clogged. 2. Change filter.
3. Gearshift Linkage Mis-adjusted. 3. Adjust linkage and repair linkage if worn or
damaged.
4. Torque Converter Drain Back
(Oil drains from torque converter
into transmission sump).4. If vehicle moves normally after 5 seconds after
shifting into gear, no repair is necessary. If longer,
inspect pump bushing for wear. Replace pump
house.
5. Rear Band Mis-adjusted. 5. Adjust band.
6. Valve Body Filter Plugged. 6. Replace fluid and filter. If oil pan and old fluid
were full of clutch disc material and/or metal
particles, overhaul will be necessary.
7. Oil Pump Gears Worn/Damaged. 7. Remove transmission and replace oil pump.
8. Governor Circuit and Solenoid
Valve Electrical Fault.8. Test with DRBTscan tool and repair as
required.
9. Hydraulic Pressure Incorrect. 9. Perform pressure test, remove transmission
and repair as needed.
10. Reaction Shaft Seal Rings
Worn/Broken.10. Remove transmission, remove oil pump and
replace seal rings.
11. Rear Clutch/Input Shaft, Rear
Clutch Seal Rings Damaged.11. Remove and disassemble transmission and
repair as necessary.
12. Regulator Valve Stuck. 12. Clean.
13. Cooler Plugged. 13. Transfer case failure can plug cooler.
WJAUTOMATIC TRANSMISSION - 42RE 21 - 17
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
SLIPS IN OVERDRIVE
FOURTH GEAR1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Overdrive Clutch Pack Worn. 2. Remove overdrive unit and rebuild clutch pack.
3. Overdrive Piston Retainer Bleed
Orifice Blown Out.3. Disassemble transmission, remove retainer and
replace orifice.
4. Overdrive Piston or Seal
Malfunction.4. Remove overdrive unit. Replace seals if worn.
Replace piston if damaged. If piston retainer is
damaged, remove and disassemble the
transmission.
5. 3-4 Shift Valve, Timing Valve or
Accumulator Malfunction.5. Remove and overhaul valve body. Replace
accumulator seals. Make sure all valves operate
freely in bores and do not bind or stick. Make sure
valve body screws are correctly tightened and
separator plates are properly positioned.
6. Overdrive Unit Thrust Bearing
Failure.6. Disassemble overdrive unit and replace thrust
bearing (NO. 1 thrust bearing is between
overdrive piston and clutch hub; NO. 2 thrust
bearing is between the planetary gear and the
direct clutch spring plate; NO. 3 thrust bearing is
between overrunning clutch hub and output shaft).
7. O/D Check Valve/Bleed Orifice
Failure.7. Check for function/secure orifice insert in O/D
piston retainer.
DELAYED 3-4
UPSHIFT (SLOW TO
ENGAGE)1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Throttle Valve Cable Mis-
adjusted.2. Adjust throttle valve cable.
3. Overdrive Clutch Pack
Worn/Burnt.3. Remove unit and rebuild clutch pack.
4. TPS Faulty. 4. Test with DRBTscan tool and replace as
necessary
5. Overdrive Clutch Bleed Orifice
Plugged.5. Disassemble transmission and replace orifice.
6. Overdrive Solenoid or Wiring
Shorted/Open.6. Test solenoid and check wiring for loose/
corroded connections or shorts/grounds. Replace
solenoid if faulty and repair wiring if necessary.
7. Overdrive Excess Clearance. 7. Remove unit. Measure end play and select
proper spacer.
8. O/D Check Valve Missing or
Stuck.8. Check for presence of check valve. Repair or
replace as required.
TORQUE
CONVERTER LOCKS
UP IN SECOND
AND/OR THIRD
GEARLockup Solenoid, Relay or Wiring
Shorted/Open.Test solenoid, relay and wiring for continuity,
shorts or grounds. Replace solenoid and relay if
faulty. Repair wiring and connectors as necessary.
HARSH 1-2, 2-3, 3-4
OR 3-2 SHIFTSLockup Solenoid Malfunction. Remove valve body and replace solenoid
assembly.
21 - 24 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

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
WJAUTOMATIC TRANSMISSION - 42RE 21 - 27
AUTOMATIC TRANSMISSION - 42RE (Continued)

(23) Check seal rings on reaction shaft support
hub. Verify that seal rings are hooked together and
that the thrust washer is properly positioned (Fig.
55). Use petroleum jelly to hold thrust washer in
place if necessary.(24) Lubricate oil pump body seal with petroleum
jelly. Lubricate pump shaft seal lip with petroleum
jelly.
(25) Thread two Pilot Stud Tools C-3288-B into
bolt holes in oil pump bore flange (Fig. 56).
(26) Align and install oil pump gasket (Fig. 56).
Fig. 53 Installing Front/Rear Clutch Assemblies
1 - INPUT SHAFT
2 - FRONT CLUTCH
3 - REAR CLUTCH
Fig. 54 Front Band Linkage Installation
1 - BAND LEVER
2 - BAND STRUT
3 - FRONT BAND
Fig. 55 Reaction Shaft Support Seal Rings And
Thrust Washer
1 - REACTION SHAFT SUPPORT HUB
2 - THRUST WASHER
3 - SEAL RINGS
Fig. 56 Installing Pilot Studs And Oil Pump Gasket
1 - OIL PUMP GASKET
2 - PILOT STUD TOOLS C-3288-B
WJAUTOMATIC TRANSMISSION - 42RE 21 - 39
AUTOMATIC TRANSMISSION - 42RE (Continued)

(11) Move transmission forward. Then raise, lower
or tilt transmission to align converter housing with
engine block dowels.
(12) Carefully work transmission forward and over
engine block dowels until converter hub is seated in
crankshaft.
(13) Install two bolts to attach converter housing
to engine.
(14) Install the upper transmission bending braces
to the torque converter housing and the overdrive
unit. Tighten the bolts to 41 N´m (30 ft.lbs.).
(15) Install remaining torque converter housing to
engine bolts. Tighten to 68 N´m (50 ft.lbs.).
(16) Install rear transmission crossmember.
Tighten crossmember to frame bolts to 68 N´m (50
ft.lbs.).
(17) Install rear support to transmission. Tighten
bolts to 47 N´m (35 ft.lbs.).
(18) Lower transmission onto crossmember and
install bolts attaching transmission mount to cross-
member. Tighten clevis bracket to crossmember bolts
to 47 N´m (35 ft.lbs.). Tighten the clevis bracket to
rear support bolt to 68 N´m (50 ft.lbs.).
(19) Remove engine support fixture.
(20) Install crankshaft position sensor. (Refer to 14
- FUEL SYSTEM/FUEL INJECTION/CRANKSHAFT
POSITION SENSOR - INSTALLATION)
(21) Install new plastic retainer grommet on any
shift cable that was disconnected. Grommets should
not be reused. Use pry tool to remove rod from grom-
met and cut away old grommet. Use pliers to snap
new grommet into cable and to snap grommet onto
lever.
(22) Connect gearshift and throttle valve cable to
transmission.
(23) Connect wires to park/neutral position switch
and transmission solenoid connector. Be sure trans-
mission harnesses are properly routed.CAUTION: It is essential that correct length bolts be
used to attach the converter to the driveplate. Bolts
that are too long will damage the clutch surface
inside the converter.
(24) Install all torque converter-to-driveplate bolts
by hand.
(25) Verify that the torque converter is pulled
flush to the driveplate. Tighten bolts to 31 N´m (270
in. lbs.).
(26) Install converter housing access cover. Tighten
bolt to 23 N´m (200 in.lbs.).
(27) Install the bell housing brace to the torque
converter cover and the engine to transmission bend-
ing brace. Tighten the bolts and nut to 41 N´m (30
ft.lbs.).
(28) Install starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - INSTALLA-
TION) and cooler line bracket.
(29) Connect cooler lines to transmission.
(30) Install transmission fill tube. Install new seal
on tube before installation.
(31) Install exhaust components.
(32) Install transfer case. Tighten transfer case
nuts to 35 N´m (26 ft.lbs.).
(33) Install the transfer case shift cable to the
cable support bracket and the transfer case shift
lever.
(34) Align and connect propeller shaft(s).
(35) Adjust gearshift linkage and throttle valve
cable if necessary.
(36) Lower vehicle.
(37) Fill transmission with MopartATF +4, type
9602, fluid.
21 - 42 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

(3) Install new oil seal in housing using Seal
Installer C-3995-A (Fig. 84).
EXTENSION HOUSING SEAL
REMOVAL
(1) Raise vehicle.
(2) Mark propeller shaft and axle yoke for align-
ment reference.
(3) Disconnect and remove propeller shaft.
(4) Remove old seal with Seal Remover C-3985-B
(Fig. 85) from overdrive housing.
INSTALLATION
(1) Place seal in position on overdrive housing.
(2) Drive seal into overdrive housing with Seal
Installer C-3995-A (Fig. 86).
(3) Carefully guide propeller shaft slip yoke into
housing and onto output shaft splines. Align marks
made at removal and connect propeller shaft to rear
axle pinion yoke.
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has two primary causes.
Fig. 83 Bushing Removal - Typical
1 - REMOVER 6957
2 - EXTENSION HOUSING BUSHING
Fig. 84 Extension Housing Seal Installation
1 - SPECIAL TOOL C-3995-A OR C-3972-A
2 - SPECIAL TOOL C-4471
Fig. 85 Removing Overdrive Housing Yoke Seal
1 - SPECIAL TOOL C-3985-B
2 - SEAL
Fig. 86 Installing Overdrive Housing Seal
1 - SPECIAL TOOL C-3995-A OR C-3972-A
2 - SPECIAL TOOL C-4471
WJAUTOMATIC TRANSMISSION - 42RE 21 - 69
EXTENSION HOUSING BUSHING (Continued)

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 snap-ring is
used to cushion the application of the clutch pack.
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
clutch retainer. The check-valve is needed to elimi-
nate the possibility of plate drag caused by centrifu-
gal force acting on the residual fluid trapped in the
clutch piston retainer.
DISASSEMBLY
(1) Remove waved snap-ring and remove pressure
plate, clutch plates and clutch discs (Fig. 92).
(2) Compress clutch piston spring with Compressor
Tool C-3575-A (Fig. 93). Be sure legs of tool are
seated squarely on spring retainer before compress-
ing spring.
(3) Remove retainer snap-ring and remove com-
pressor tool.
(4) Remove spring retainer and clutch spring. Note
position of retainer on spring for assembly reference.
(5) Remove clutch piston from clutch retainer.
Remove piston by rotating it up and out of retainer.
(6) Remove seals from clutch retainer piston bore
and clutch retainer hub. Discard both seals as they
are not reusable.
INSPECTION
Inspect the front clutch components. Replace the
clutch discs if warped, worn, scored, burned or
charred, or if the facing is flaking off. Replace the
steel plates if heavily scored, warped, or broken. Be
sure the driving lugs on the plates are in good con-
dition. The lugs must not be bent, cracked or dam-
aged in any way.
Replace the clutch spring and spring retainer if
either is distorted, warped or broken.Check the lug grooves in the clutch retainer. The
steel plates should slide freely in the slots. Replace
the retainer if the grooves are worn or damaged.
Check action of the check ball in the retainer (Fig.
94). The ball must move freely and not stick.
NOTE: Inspect the clutch retainer bushings care-
fully (Fig. 95). The retainer bushings are NOT ser-
viceable. It will be necessary to replace the retainer
if either bushing is scored, or worn.
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.
ASSEMBLY
NOTE: The 42RE transmission uses four plates and
discs for the front clutch.
(1) Soak clutch discs in transmission fluid while
assembling other clutch parts.
(2) Install new seals in the clutch retainer lower
groove and on outer diameter of the retainer hub. Be
sure lip of each seal faces interior of clutch retainer.
(3) Lubricate lips of the retainer seals with liberal
quantity of MopartDoor Ease. Then lubricate
retainer hub, bore and piston with light coat of trans-
mission fluid.
(4) Install clutch piston in retainer (Fig. 96). Use
twisting motion to seat piston in bottom of retainer.
CAUTION: Never push the clutch piston straight in.
This will fold the seals over causing leakage and
clutch slip.
(5) Position spring in clutch piston (Fig. 97).
(6) Position spring retainer on top of piston spring.
Make sure retainer is properly installed (Fig. 92).
(7) Compress piston spring and retainer with Com-
pressor Tool C-3575-A (Fig. 93). Then install new
snap-ring to secure spring retainer and spring.
(8) Install clutch plates and discs (Fig. 92). Install
steel plate then disc until all plates and discs are
installed. The front clutch uses 4 clutch discs and
plates in a 42RE transmission.
(9) Install pressure plate and waved snap-ring
(Fig. 92).
Clearance should be 1.70 to 3.40 mm (0.067 to
0.134 in.). If clearance is incorrect, clutch discs,
plates, pressure plates and snap-ring may have to be
changed.
21 - 74 AUTOMATIC TRANSMISSION - 42REWJ
FRONT CLUTCH (Continued)

INCORRECT if the engine starts in one but not both
positions. If the engine starts in any position other
than PARK or NEUTRAL, or if the engine will not
start at all, the park/neutral position switch or TRS
may be faulty.
(1) Shift transmission into PARK.
(2) Remove floor console as necessary for access to
the shift cable adjustment. (Refer to 23 - BODY/IN-
TERIOR/FLOOR CONSOLE - REMOVAL)
(3) Loosen the shift cable adjustment screw (Fig.
106).
(4) Raise vehicle.
(5) Unsnap cable eyelet from transmission shift
lever (Fig. 107).
(6) Verify transmission shift lever is in PARK
detent by moving lever fully rearward. Last rearward
detent is PARK position.
(7) Verify positive engagement of transmission
park lock by attempting to rotate propeller shaft.
Shaft will not rotate when park lock is engaged.
(8) Snap cable eyelet onto transmission shift lever.
(9) Lower vehicle
(10) Tighten the shift cable adjustment screw to 7
N´m (65 in.lbs.).
(11) Verify correct operation.
(12) Install any floor console components removed
for access. (Refer to 23 - BODY/INTERIOR/FLOOR
CONSOLE - INSTALLATION)
OIL PUMP
DESCRIPTION
The oil pump (Fig. 108) is located in the pump
housing inside the bell housing of the transmission
case. The oil pump consists of an inner and outer
gear (Fig. 109), a housing, and a cover that also
serves as the reaction shaft support.
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate, the clearance between the gear teeth
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction draws
fluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.
Fig. 106 Shift Cable at the Shifter
1 - SHIFT LEVER PIN
2 - ADJUSTMENT SCREW
3 - SHIFT CABLE
4 - SHIFTER ASSEMBLY BRACKET
Fig. 107 Shift Cable at Transmission
1 - TRANSMISSION SHIFTER CABLE
2 - THROTTLE VALVE CABLE
3 - TRANSFER CASE SHIFTER CABLE
4 - TRANSFER CASE SHIFTER CABLE BRACKET RETAINING
BOLT(S)
5 - THROTTLE VALVE CABLE BRACKET RETAINING BOLT
6 - ELECTRICAL CONNECTORS
7 - TRANSMISSION FLUID LINES
21 - 80 AUTOMATIC TRANSMISSION - 42REWJ
GEARSHIFT CABLE (Continued)