Transfer JEEP GRAND CHEROKEE 2002 WJ / 2.G Manual PDF

REVERSE POWERFLOW
When the gear selector is moved into the
REVERSE position (Fig. 5), the front clutch and the
rear band are applied. With the application of the
front clutch, engine torque is applied to the sun gear,
turning it in a clockwise direction. The clockwise
rotation of the sun gear causes the rear planet pin-
ions to rotate against engine rotation in a counter-
clockwise direction. The rear band is holding the low
reverse drum, which is splined to the rear carrier.
Since the rear carrier is being held, the torque fromthe planet pinions is transferred to the rear annulus
gear, which is splined to the output shaft. The output
shaft in turn rotates with the annulus gear in a
counterclockwise direction giving a reverse gear out-
put. The entire transmission of torque is applied to
the rear planetary gearset only. Although there is
torque input to the front gearset through the sun
gear, no other member of the gearset is being held.
During the entire reverse stage of operation, the
front planetary gears are in an idling condition.
Fig. 5 Reverse Powerflow
1 - FRONT CLUTCH ENGAGED 5 - OUTPUT SHAFT
2 - OUTPUT SHAFT 6 - INPUT SHAFT
3 - LOW/REVERSE BAND APPLIED 7 - FRONT CLUTCH ENGAGED
4 - INPUT SHAFT 8 - LOW/REVERSE BAND APPLIED
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AUTOMATIC TRANSMISSION - 42RE (Continued)

FIRST GEAR POWERFLOW
When the gearshift lever is moved into the DRIVE
position the transmission goes into first gear (Fig. 6).
As soon as the transmission is shifted from PARK or
NEUTRAL to DRIVE, the rear clutch applies, apply-
ing the rear clutch pack to the front annulus gear.
Engine torque is now applied to the front annulus
gear turning it in a clockwise direction. With the
front annulus gear turning in a clockwise direction, it
causes the front planets to turn in a clockwise direc-
tion. The rotation of the front planets cause the sun
to revolve in a counterclockwise direction. The sun
gear now transfers its counterclockwise rotation tothe rear planets which rotate back in a clockwise
direction. With the rear annulus gear stationary, the
rear planet rotation on the annulus gear causes the
rear planet carrier to revolve in a counterclockwise
direction. The rear planet carrier is splined into the
low-reverse drum, and the low reverse drum is
splined to the inner race of the over-running clutch.
With the over-running clutch locked, the planet car-
rier is held, and the resulting torque provided by the
planet pinions is transferred to the rear annulus
gear. The rear annulus gear is splined to the output
shaft and rotated along with it (clockwise) in an
underdrive gear reduction mode.
Fig. 6 First Gear Powerflow
1 - OUTPUT SHAFT 5 - OVER-RUNNING CLUTCH HOLDING
2 - OVER-RUNNING CLUTCH HOLDING 6 - INPUT SHAFT
3 - REAR CLUTCH APPLIED 7 - REAR CLUTCH APPLIED
4 - OUTPUT SHAFT 8 - INPUT SHAFT
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AUTOMATIC TRANSMISSION - 42RE (Continued)

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
NO DRIVE RANGE
(REVERSE OK)1. Fluid Level Low. 1. Add fluid and check for leaks if drive is
restored.
2. Gearshift Linkage/Cable
Loose/Misadjusted.2. Repair or replace linkage components.
3. Rear Clutch Burnt. 3. Remove and disassemble transmission and
rear clutch and seals. Repair/replace worn or
damaged parts as needed.
4. Valve Body Malfunction. 4. Remove and disassemble valve body. Replace
assembly if any valves or bores are damaged.
5. Transmission Overrunning
Clutch Broken.5. Remove and disassemble transmission.
Replace overrunning clutch.
6. Input Shaft Seal Rings
Worn/Damaged.6. Remove and disassemble transmission.
Replace seal rings and any other worn or
damaged parts.
7. Front Planetary Failed Broken. 7. Remove and repair.
NO DRIVE OR
REVERSE (VEHICLE
WILL NOT MOVE)1. Fluid Level Low. 1. Add fluid and check for leaks if drive is
restored.
2. Gearshift Linkage/Cable
Loose/Misadjusted.2. Inspect, adjust and reassemble linkage as
needed. Replace worn/damaged parts.
3. U-Joint/Axle/Transfer Case
Broken.3. Perform preliminary inspection procedure for
vehicle that will not move. Refer to procedure in
diagnosis section.
4. Filter Plugged. 4. Remove and disassemble transmission. Repair
or replace failed components as needed. Replace
filter. If filter and fluid contained clutch material or
metal particles, an overhaul may be necessary.
Perform lube flow test. Flush oil. Replace cooler
as necessary.
5. Oil Pump Damaged. 5. Perform pressure test to confirm low pressure.
Replace pump body assembly if necessary.
6. Valve Body Malfunctioned. 6. Check and inspect valve body. Replace valve
body (as assembly) if any valve or bore is
damaged. Clean and reassemble correctly if all
parts are in good condition.
7. Transmission Internal
Component Damaged.7. Remove and disassemble transmission. Repair
or replace failed components as needed.
8. Park Sprag not Releasing -
Check Stall Speed, Worn/
Damaged/Stuck.8. Remove, disassemble, repair.
9. Torque Converter Damage. 9. Inspect and replace as required.
21 - 18 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
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AUTOMATIC TRANSMISSION - 42RE (Continued)

(17) Disconnect throttle valve cable from transmis-
sion bracket and throttle valve lever (Fig. 15).
(18) Disconnect transfer case shift cable from the
transfer case shift lever (Fig. 16).
(19) Remove the clip securing the transfer case
shift cable into the cable support bracket.
(20) Disconnect transmission fluid cooler lines at
transmission fittings and clips.
(21) Support rear of engine with safety stand or
jack.(22) Raise transmission slightly with service jack
to relieve load on crossmember and supports.
(23) Remove bolts securing rear support and cush-
ion to transmission and crossmember (Fig. 17).
(24) Remove bolts attaching crossmember to frame
and remove crossmember.
(25) Remove transfer case (Fig. 18) and (Fig. 19).
Fig. 15 Throttle Valve Cable
1 - THROTTLE VALVE CABLE
2 - THROTTLE VALVE LEVER
3 - THROTTLE BODY
Fig. 16 Transfer Case Shift Cable
1 - TRANSFER CASE SHIFT LEVER
2 - TRANSFER CASE SHIFT CABLE
Fig. 17 Rear Transmission Crossmember
1 - CROSSMEMBER
2 - REAR TRANSMISSION MOUNT
Fig. 18 Remove NV247 Transfer Case
1 - NV247 TRANSFER CASE
21 - 28 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

(26) Remove bolts holding the upper transmission
bending braces to the torque converter housing and
the overdrive unit (Fig. 20).
(27) Remove all remaining converter housing bolts.
(28) Carefully work transmission and torque con-
verter assembly rearward off engine block dowels.
(29) Hold torque converter in place during trans-
mission removal.
(30) Lower transmission and remove assembly
from under the vehicle.
(31) To remove torque converter, carefully slide
torque converter out of the transmission.
DISASSEMBLY
(1) Clean transmission exterior with steam gun or
with solvent. Wear eye protection during cleaning
operations.
(2) Place transmission in a vertical position.(3) Measure input shaft end play as follows (Fig.
21).
(a) Attach Adapter 8266-6 to Handle 8266-8.
(b) Attach dial indicator C-3339 to Handle
8266-8.
(c) Install the assembled tool onto the input
shaft of the transmission and tighten the retaining
screw on Adapter 8266-6 to secure it to the input
shaft.
(d) Position the dial indicator plunger against a
flat spot on the oil pump and zero the dial indica-
tor.
(e) Move the input shaft in and out. Record the
maximum travel for assembly reference.
(4) Remove shift and throttle levers from valve
body manual lever shaft.
(5) Place transmission in horizontal position.
(6) Remove transmission oil pan and gasket.
(7) Remove filter from valve body (Fig. 22). Keep
filter screws separate from other valve body screws.
Filter screws are longer and should be kept with fil-
ter.
(8) Remove park/neutral position switch.
(9) Remove hex head bolts attaching valve body to
transmission case (Fig. 23). A total of 10 bolts are
used. Note different bolt lengths for assembly refer-
ence.
Fig. 19 Remove NV242 Transfer Case
1 - NV242 TRANSFER CASE
Fig. 20 Remove Upper Transmission Bending
Braces
1 - TRANSMISSION BENDING BRACES
Fig. 21 Checking Input Shaft End Play
1 - TOOL 8266-8
2 - TOOL 8266-6
3 - TOOL C-3339
WJAUTOMATIC TRANSMISSION - 42RE 21 - 29
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)

PRESSURE TEST
Overdrive clutch Fourth gear only Pressure should be 469-496 kPa (68-72 psi) with
closed throttle and increase to 620-896 kPa (90-130
psi) at 1/2 to 3/4 throttle.
Line pressure (at
accumulator)Closed throttle 372-414 kPa (54-60 psi).
Front servo Third or Fourth gear only No more than 21 kPa (3 psi) lower than line pressure.
Rear servo 1 range No more than 21 kPa (3 psi) lower than line pressure.
R range 1103 kPa (160 psi) at idle, builds to 1862 kPa (270 psi)
at 1600 rpm.
Governor D range closed throttle Pressure should respond smoothly to changes in mph
and return to 0-7 kPa (0-1.5 psi) when stopped with
transmission in D, 1, 2. Pressure above 7 kPa (1.5 psi)
at stand still will prevent transmission from
downshifting.
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fitting, cooler line at trans 18 13 -
Bolt, torque convertor 31 - 270
Bolt, clevis bracket to crossmember 47 35 -
Bolt, clevis bracket to rear support 68 50 -
Bolt, driveplate to crankshaft 75 55 -
Plug, front band reaction 17 13 -
Locknut, front band adj. 34 25 -
Switch, park/neutral 34 25 -
Bolt, fluid pan 17 13 -
Screws, fluid filter 4 - 35
Bolt, oil pump 20 15 -
Bolt, overrunning clutch cam 17 13 -
Bolt, O/D to trans. 34 25 -
Bolt, O/D piston retainer 17 13 -
Plug, pressure test port 14 10 -
Bolt, reaction shaft support 20 15 -
Locknut, rear band 41 30 -
Bolt, speedometer adapter 11 - 100
Screw, vehicle speed sensor 2.5 - 21
Bolt, valve body to case 12 - 100
Sensor, trans speed 27 20 -
Screw, solenoid wiring connector 4 - 35
Screw, solenoid to transfer plate 4 - 35
21 - 56 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

(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)