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

HYDRAULIC FLOW IN DRIVE THIRD GEAR (CONVERTER CLUTCH NOT APPLIED)
21 - 48 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

HYDRAULIC FLOW IN DRIVE THIRD GEAR (CONVERTER CLUTCH APPLIED)
WJAUTOMATIC TRANSMISSION - 42RE 21 - 49
AUTOMATIC TRANSMISSION - 42RE (Continued)

HYDRAULIC FLOW IN DRIVE FOURTH GEAR (CONVERTER CLUTCH NOT APPLIED)
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AUTOMATIC TRANSMISSION - 42RE (Continued)

HYDRAULIC FLOW IN DRIVE FOURTH GEAR (CONVERTER CLUTCH APPLIED)
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AUTOMATIC TRANSMISSION - 42RE (Continued)

SPECIFICATIONS
TRANSMISSION
GENERAL
Component Metric Inch
Planetary end play 0.127-1.22
mm0.005-0.048
in.
Input shaft end play 0.56-2.31
mm0.022-0.091
in.
Clutch pack clearance/
Front.1.70-
3.40mm0.067-0.134
in.
Clutch pack clearance/
Rear.0.559-0.914
mm0.022-0.036
in.
Front clutch 4 discs
Rear clutch 4 discs
Overdrive clutch 3 discs
Component Metric Inch
Direct clutch 6 discs
42RE Band adjustment
from 72 in. lbs.
Front band Back off 3 turns
Rear band Back off 4 turns
Recommended fluid MoparTATF +4, type 9602
GEAR RATIOS
1ST GEAR 2.74:1
2ND GEAR 1.54:1
3RD GEAR 1.0:1
4TH GEAR 0.69:1
REVERSE 2.21:1
THRUST WASHER/SPACER/SNAP-RING DIMENSIONS
Component Metric Inch
Front clutch thrust washer (reaction shaft
support hub)1.55 mm 0.061 in.
Rear clutch thrust washer (clutch retainer) 1.55 mm 0.061 in.
Intermediate shaft thrust plate (shaft hub pilot) Select fit to set end play
Output shaft thrust washer (rear clutch hub) 1.5-1.6 mm 0.060-0.063 in.
Rear clutch pack snap-ring 1.5 mm 0.060 in.
1.95 mm 0.076 in.
2.45 mm 0.098 in.
Planetary geartrain snap-ring (at front of output shaft) Select fit (three thicknesses avalible)
Overdrive piston thrust plate Thrust plate and
spacer are select fit.
Refer to size charts
and selection
procedures in
Overdrive Unit D&A
procedures Intermiediate shaft spacer
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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
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AUTOMATIC TRANSMISSION - 42RE (Continued)

ACCUMULATOR
DESCRIPTION
The accumulator (Fig. 62) is a hydraulic device
that has the sole purpose of cushioning the applica-
tion of a band or clutch. The accumulator consists of
a dual-land piston and a spring located in a bore in
the transmission case. The 3-4 accumulator is located
in a housing attached to the side of the valve body
(Fig. 63).
OPERATION
Both the accumulator and the 3-4 accumulator
function the same. Line pressure is directed to the
small end of the piston when the transmission is
placed into a DRIVE position (Fig. 64), bottoming it
against the accumulator plate. When the 1-2 upshift
occurs (Fig. 65), line pressure is directed to the large
end of the piston and then to the kickdown servo. As
the line pressure reaches the accumulator, the com-
bination of spring pressure and line pressure forces
the piston away from the accumulator plate. This
causes a balanced pressure situation, which results
in a cushioned band application. After the kickdown
servo has become immovable, line pressure will fin-
ish pushing the accumulator up into its bore. When
the large end of the accumulator piston is seated in
its bore, the band or clutch is fully applied.
NOTE: The accumulator is shown in the inverted
position for illustrative purposes.
INSPECTION
Inspect the accumulator piston and seal rings (Fig.
66). Replace the seal rings if worn or cut. Replace the
piston if chipped or cracked.
Check condition of the accumulator inner and
outer springs (Fig. 66). Replace the springs if the
coils are cracked, distorted or collapsed.
Fig. 62 Accumulator
1 - ACCUMULATOR PISTON
2 - PISTON SPRING
Fig. 63 3-4 Accumulator and Housing
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
Fig. 64 Accumulator in DRIVE - FIRST Gear Position
1 - LINE PRESSURE
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BANDS
DESCRIPTION
KICKDOWN (FRONT) BAND
The kickdown, or ªfrontº, band (Fig. 67) holds the
common sun gear of the planetary gear sets. The
front (kickdown) band is made of steel, and faced on
its inner circumference with a friction-type lining.
One end of the band is anchored to the transmissioncase, and the other is acted on with a pushing force
by a servo piston. The front band is a single-wrap
design (the band does not completely encompass/
wrap the drum that it holds).
LOW/REVERSE (REAR) BAND
The low/reverse band, or ªrearº, band (Fig. 68) is
similar in appearance and operation to the front
band. The rear band is slightly different in that it
does not use a link bar, but is acted directly on by
the apply lever. This is referred to as a double-wrap
band design (the drum is completely encompassed/
wrapped by the band). The double-wrap band pro-
vides a greater holding power in comparison to the
single-wrap design.
OPERATION
KICKDOWN (FRONT) BAND
The kickdown band holds the common sun gear of
the planetary gear sets by applying and holding the
front clutch retainer, which is splined to the sun gear
driving shell, and in turn splined directly to the sun
gear. The application of the band by the servo is typ-
ically done by an apply lever and link bar.
LOW/REVERSE (REAR) BAND
The rear band holds the rear planet carrier sta-
tionary by being mounted around and applied to the
low/reverse drum.
Fig. 65 Accumulator in SECOND Gear Position
1 - BOTTOM OF BORE
2 - LINE PRESSURE
3 - SHUTTLE VALVE
Fig. 66 Accumulator Components
1 - INNER SPRING
2 - ACCUMULATOR PISTON
3 - OUTER SPRING
4 - SEAL RINGS
Fig. 67 Front Band
1 - FRONT BAND
2 - TRANSMISSION HOUSING
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BANDS (Continued)

BRAKE TRANSMISSION SHIFT
INTERLOCK MECHANISM
DESCRIPTION
The Brake Transmission Shifter/Ignition Interlock
(BTSI), is a cable and solenoid operated system. It
interconnects the automatic transmission floor
mounted shifter to the steering column ignition
switch (Fig. 71).
OPERATION
The system locks the shifter into the PARK posi-
tion. The interlock system is engaged whenever the
ignition switch is in the LOCK or ACCESSORY posi-
tion. An additional electrically activated feature will
prevent shifting out of the PARK position unless the
brake pedal is depressed approximately one-half an
inch. A magnetic holding device in the shifter assem-
bly is energized when the ignition is in the RUN
position. When the key is in the RUN position and
the brake pedal is depressed, the shifter is unlocked
and will move into any position. The interlock system
also prevents the ignition switch from being turned
to the LOCK or ACCESSORY position, unless the
shifter is fully locked into the PARK position.
DIAGNOSIS AND TESTING - BRAKE
TRANSMISSION SHIFT INTERLOCK
(1) Verify that the key can only be removed in the
PARK position
(2) When the shift lever is in PARK And the shift
handle pushbutton is in the ªOUTº position, the igni-
tion key cylinder should rotate freely from OFF to
LOCK. When the shifter is in any other gear or neu-
tral position, the ignition key cylinder should not
rotate to the LOCK position.
(3) Shifting out of PARK should not be possible
when the ignition key cylinder is in the OFF posi-
tion.
(4) Shifting out of PARK should not be possible
while applying normal pushbutton force and ignition
key cylinder is in the RUN or START positions
unless the foot brake pedal is depressed approxi-
mately 1/2 inch (12mm).
(5) Shifting out of PARK should not be possible
when the ignition key cylinder is in the ACCESSORY
or LOCK positions.
(6) Shifting between any gears, NEUTRAL or into
PARK may be done without depressing foot brake
pedal with ignition switch in RUN or START posi-
tions.
Fig. 71 Ignition Interlock Cable
1 - SHIFT MECHANISM 4 - STEERING COLUMN ASSEMBLY
2 - SHIFTER BTSI LEVER 5 - INTERLOCK CABLE
3 - ADJUSTMENT CLIP
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ADJUSTMENTS - BRAKE TRANSMISSION
SHIFT INTERLOCK
The park interlock cable is part of the brake/shift
lever interlock system. Correct cable adjustment is
important to proper interlock operation. The gear
shift and park lock cables must both be correctly
adjusted in order to shift out of PARK.
ADJUSTMENT PROCEDURE
(1) Remove floor console as necessary for access to
the brake transmission shift interlock cable. (Refer to
23 - BODY/INTERIOR/FLOOR CONSOLE -
REMOVAL)
(2) Shift the transmission into the PARK position.
(3) Turn ignition switch to LOCK position.Be
sure ignition key cylinder is in the LOCK posi-
tion. Cable will not adjust correctly in any
other position.
(4) Pull cable lock button up to release cable (Fig.
72).
(5) Ensure that the cable is free to self-adjust by
pushing cable rearward and releasing.
(6) Push lock button down until it snaps in place.
BTSI FUNCTION CHECK
(1) Verify removal of ignition key allowed in PARK
position only.
(2) When the shift lever is in PARK, and the shift
handle push-button is in the out position, the igni-
tion key cylinder should rotate freely from off to lock.
When the shifter is in any other position, the ignition
key should not rotate from off to lock.
(3) Shifting out of PARK should be possible when
the ignition key cylinder is in the off position.
(4) Shifting out of PARK should not be possible
while applying normal push-button force, and igni-
tion key cylinder is in the run or start positions,
unless the foot brake pedal is depressed approxi-
mately 1/2 inch (12mm).
(5) Shifting out of PARK should not be possible
when the ignition key cylinder is in the accessory or
lock position.
(6) Shifting between any gear and NEUTRAL, or
PARK, may be done without depressing foot brake
with ignition switch in run or start positions.
(7) The floor shifter lever and gate positions
should be in alignment with all transmission detent
positions.
Fig. 72 Brake Transmission Shift Interlock Cable
1 - SHIFT MECHANISM 4 - STEERING COLUMN ASSEMBLY
2 - SHIFTER BTSI LEVER 5 - INTERLOCK CABLE
3 - ADJUSTMENT CLIP
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BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM (Continued)