2002 JEEP GRAND CHEROKEE o2 location

between the rollers and cam. This increased clear-
ance between the rollers and cam results in a free-
wheeling condition. When the inner race attempts to
rotate counterclockwise, the action causes the rollers
to roll in the same direction as the race, aided by the
pushing of the springs. As the rollers try to move in
the same direction as the inner race, they are
wedged between the inner and outer races due to the
design of the cam. In this condition, the clutch is
locked and acts as one unit.
DISASSEMBLY
NOTE: To service the overrunning clutch cam and
the overdrive piston retainer, the transmission
geartrain and the overdrive unit must be removed
from the transmission.
(1) Remove the overdrive piston (Fig. 190).
(2) Remove the overdrive piston retainer bolts.
(3) Remove overdrive piston retainer.
(4) Remove case gasket.
(5) Mark the position of the overrunning clutch
cam in the case (Fig. 191).
(6) Remove the overrunning clutch cam bolts.
(7) Remove the overrunning clutch cam.
CLEANING
Clean the overrunning clutch assembly, clutch cam,
low-reverse drum, and overdrive piston retainer in
solvent. Dry them with compressed air after clean-
ing.
INSPECTION
Inspect condition of each clutch part after cleaning.
Replace the overrunning clutch roller and spring
assembly if any rollers or springs are worn or dam-
aged, or if the roller cage is distorted, or damaged.
Replace the cam if worn, cracked or damaged.
Replace the low-reverse drum if the clutch race,
roller surface or inside diameter is scored, worn or
damaged.Do not remove the clutch race from
the low-reverse drum under any circumstances.
Replace the drum and race as an assembly if
either component is damaged.
Examine the overdrive piston retainer carefully for
wear, cracks, scoring or other damage. Be sure the
retainer hub is a snug fit in the case and drum.
Replace the retainer if worn or damaged.
ASSEMBLY
(1) Examine bolt holes in overrunning clutch cam.
Note that one hole isnot threaded(Fig. 192). This
hole must align with blank area in clutch cam bolt
circle (Fig. 193). Mark hole location on clutch cam
and blank area in case with grease pencil, paint
stripe, or scribe mark for assembly reference.
(2) Mark location of non-threaded hole in clutch
cam and blank area in bolt circle with grease pencil.
(3) Align and install overrunning clutch and cam
in case (Fig. 194). Be sure cam is correctly installed.
Bolt holes in cam are slightly countersunk on one
side. Be sure this side of cam faces rearward (toward
piston retainer).
(4) Verify that non-threaded hole in clutch cam is
properly aligned. Check alignment by threading a
bolt into each bolt hole. Adjust clutch cam position if
necessary.
Fig. 190 Overdrive Piston Removal
1 - OVERDRIVE CLUTCH PISTON
2 - INTERMEDIATE SHAFT
3 - SELECTIVE SPACER
4 - PISTON RETAINER
Fig. 191 Overrunning Clutch Cam Removal
1 - ALIGN MARKS IDENTIFYING NON-THREADED HOLE IN
CAM AND CASE
2 - OVERRUNNING CLUTCH ASSEMBLY
21 - 106 AUTOMATIC TRANSMISSION - 42REWJ
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)

(5) Install and tighten overrunning clutch cam
bolts to 17 N´m (13 ft. lbs.) torque. Note that clutch
cam bolts are shorter than piston retainer bolts.
(6) Install new gasket at rear of transmission case.
Use petroleum jelly to hold gasket in place. Be sure
to align governor feed holes in gasket with feed pas-
sages in case (Fig. 195). Also install gasket before
overdrive piston retainer. Center hole in gasket is
smaller than retainer and cannot be installed over
retainer.(7) Position overdrive piston retainer on transmis-
sion case and align bolt holes in retainer, gasket and
case (Fig. 196). Then install and tighten retainer
bolts to 17 N´m (13 ft. lbs.) torque.
Fig. 192 Location Of Non-Threaded Hole In Clutch
Cam
1 - NON-THREADED HOLE
2 - OVERRUNNING CLUTCH CAM
Fig. 193 Location Of Blank Area In Clutch Cam Bolt
Circle
1 - OVERRUNNING CLUTCH CAM SEAT IN CASE
2 - NON-THREADED HOLE IN CLUTCH CAM ALIGNS HERE
(BLANK AREA) OF SEAT
Fig. 194 Overrunning Clutch Installation
1 - ALIGN MARKS IDENTIFYING NON-THREADED HOLE IN
CAM AND CASE
2 - OVERRUNNING CLUTCH ASSEMBLY
Fig. 195 Installing/Aligning Case Gasket
1 - CASE GASKET
2 - BE SURE GOVERNOR TUBE FEED HOLES IN CASE AND
GASKET ARE ALIGNED
WJAUTOMATIC TRANSMISSION - 42RE 21 - 107
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)

INSPECTION
Check sun gear and driving shell condition.
Replace the gear if damaged or if the bushings are
scored or worn. The bushings are not serviceable.
Replace the driving shell if worn, cracked or dam-
aged.Replace planetary gear sets if gears, pinion pins, or
carrier are damaged in any way. Replace the annulus
gears and supports if either component is worn or
damaged.
Inspect the geartrain spacers, thrust plates, snap-
rings, and thrust washers. Replace any of these parts
that are worn, distorted or damaged. Do not attempt
to reuse these parts.
The planetary gear thrust washers are different
sizes. The large diameter washers go on the front
planetary and the smaller washers go on the rear
planetary. All the washers have four locating tabs on
them. These tabs fit in the holes or slots provided in
each planetary gear.
Inspect the output shaft carefully. Pay particular
attention to the machined bushing/bearing surfaces
on the shaft and the governor valve shaft bore at the
shaft rear.
Replace the output shaft if the machined surfaces
are scored, pitted, or damaged in any way. Also
replace the shaft if the splines are damaged, or
exhibits cracks at any location (especially at the gov-
ernor valve shaft bore).
The annulus gears can be removed from their sup-
ports if necessary. Just remove the snap-rings and
separate the two parts when replacement is neces-
sary. In addition, the annulus gear bushings can be
replaced if severely worn, or scored. However it is not
necessary to replace the bushings if they only exhibit
normal wear. Check bushing fit on the output shaft
to be sure.
ASSEMBLY
(1) Lubricate output shaft and planetary compo-
nents with transmission fluid. Use petroleum jelly to
lubricate and hold thrust washers and plates in posi-
tion.
(2) Assemble rear annulus gear and support if dis-
assembled. Be sure support snap-ring is seated and
that shoulder-side of support faces rearward (Fig.
208).
(3) Install rear thrust washer on rear planetary
gear. Use enough petroleum jelly to hold washer in
place. Also be sure all four washer tabs are properly
engaged in gear slots.
(4) Install rear annulus over and onto rear plane-
tary gear (Fig. 208).
(5) Install assembled rear planetary and annulus
gear on output shaft (Fig. 209). Verify that assembly
is fully seated on shaft.
Fig. 206 Front Planetary And Annulus Gear
Disassembly
1 - FRONT ANNULUS
2 - THRUST WASHER
3 - THRUST PLATE
4 - FRONT THRUST WASHER
5 - FRONT PLANETARY
Fig. 207 Removing Driving Shell, Rear Planetary
And Rear Annulus
1 - REAR ANNULUS
2 - REAR PLANETARY
3 - DRIVING SHELL
4 - OUTPUT SHAFT
WJAUTOMATIC TRANSMISSION - 42RE 21 - 113
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

STATOR
The stator assembly (Fig. 248) is mounted on a sta-
tionary shaft which is an integral part of the oil
pump. The stator is located between the impeller and
turbine within the torque converter case (Fig. 249).
The stator contains an over-running clutch, which
allows the stator to rotate only in a clockwise direc-
tion. When the stator is locked against the over-run-
ning clutch, the torque multiplication feature of the
torque converter is operational.
TORQUE CONVERTER CLUTCH (TCC)
The TCC (Fig. 250) was installed to improve the
efficiency of the torque converter that is lost to the
slippage of the fluid coupling. Although the fluid cou-
pling provides smooth, shock-free power transfer, it is
natural for all fluid couplings to slip. If the impeller
and turbine were mechanically locked together, a
zero slippage condition could be obtained. A hydraulic
piston was added to the turbine, and a friction mate-
rial was added to the inside of the front cover to pro-
vide this mechanical lock-up.
Fig. 248 Stator Components
1 - CAM (OUTER RACE)
2 - ROLLER
3 - SPRING
4 - INNER RACE
Fig. 249 Stator Location
1-STATOR
2 - IMPELLER
3 - FLUID FLOW
4 - TURBINE
Fig. 250 Torque Converter Clutch (TCC)
1 - IMPELLER FRONT COVER
2 - THRUST WASHER ASSEMBLY
3 - IMPELLER
4-STATOR
5 - TURBINE
6 - PISTON
7 - FRICTION DISC
WJAUTOMATIC TRANSMISSION - 42RE 21 - 131
TORQUE CONVERTER (Continued)

VALVE BODY
DESCRIPTION
The valve body consists of a cast aluminum valve
body, a separator plate, and transfer plate. The valve
body contains valves and check balls that control
fluid delivery to the torque converter clutch, bands,
and frictional clutches. The valve body contains the
following components (Fig. 255), (Fig. 256), (Fig.
257), and (Fig. 258):
²Regulator valve
²Regulator valve throttle pressure plug
²Line pressure plug and sleeve
²Kickdown valve
²Kickdown limit valve
²1-2 shift valve
²1-2 control valve
²2-3 shift valve²2-3 governor plug
²3-4 shift valve
²3-4 timing valve
²3-4 quick fill valve
²3-4 accumulator
²Throttle valve
²Throttle pressure plug
²Switch valve
²Manual valve
²Converter clutch lock-up valve
²Converter clutch lock-up timing Valve
²Shuttle valve
²Shuttle valve throttle plug
²Boost Valve
²10 check balls
By adjusting the spring pressure acting on the reg-
ulator valve, transmission line pressure can be
adjusted.
Fig. 255 Upper Housing Control Valve Locations
1 - UPPER HOUSING 8 - MANUAL VALVE
2 - REGULATOR VALVE 9 - 1-2 GOVERNOR PLUG
3 - SWITCH VALVE 10 - GOVERNOR PLUG COVER
4 - REGULATOR VALVE SPRING 11 - THROTTLE PLUG
5 - KICKDOWN VALVE 12 - 2-3 GOVERNOR PLUG
6 - KICKDOWN DETENT 13 - SHUTTLE VALVE PRIMARY SPRING
7 - THROTTLE VALVE AND SPRING
WJAUTOMATIC TRANSMISSION - 42RE 21 - 135

Fig. 256 Shuttle and Boost Valve Locations
1 - SPRING 8 - SHUTTLE VALVE COVER
2 - RETAINER 9 - SHUTTLE VALVE
3 - BOOST VALVE 10 - SHUTTLE VALVE PRIMARY SPRING
4 - BOOST VALVE PLUG 11 - GOVERNOR PLUG COVER
5 - SPRING GUIDES 12 - THROTTLE PLUG
6 - E-CLIP 13 - UPPER HOUSING
7 - SHUTTLE VALVE SECONDARY SPRING 14 - BOOST VALVE COVER
21 - 136 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

Fig. 257 Upper Housing Shift Valve and Pressure Plug Locations
1 - UPPER HOUSING 8 - RETAINER
2 - 1-2 SHIFT VALVE AND SPRING 9 - 1-2 SHIFT CONTROL VALVE AND SPRING
3 - 2-3 SHIFT VALVE AND SPRING 10 - PRESSURE PLUG COVER
4 - 2-3 THROTTLE PLUG 11 - LINE PRESSURE PLUG
5 - LIMIT VALVE HOUSING 12 - PLUG SLEEVE
6 - LIMIT VALVE COVER 13 - THROTTLE PRESSURE SPRING AND PLUG
7 - LIMIT VALVE AND SPRING
WJAUTOMATIC TRANSMISSION - 42RE 21 - 137
VALVE BODY (Continued)

OPERATION
NOTE: Refer to the Hydraulic Schematics for a
visual aid in determining valve location, operation
and design.
CHECK BALLS
CHECK BALL NUMBER DESCRIPTION
1 Allows either the manual valve to put line pressure on the 1-2 governor plug or
the KD Valve to put WOT line pressure on the 1-2 governor plug.
2 Allows either the manual valve to put line pressure on the 2-3 governor plug or
the KD Valve to put WOT line pressure on the 2-3 governor plug.
3 Allows either the Reverse circuit or the 3rd gear circuit to pressurize the front
clutch.
4 Allows either the Manual Low circuit from the Manual Valve or the Reverse
from the Manual Valve circuit to pressurize the rear servo.
5 Directs line pressure to the spring end of the 2-3 shift valve in either Manual
Low or Manual 2nd, forcing the downshift to 2nd gear regardless of governor
pressure.
6 Provides a by-pass around the front servo orifice so that the servo can release
quickly.
7 Provides a by-pass around the rear clutch orifice so that the clutch can release
quickly.
8 Directs reverse line pressure through an orifice to the throttle valve eliminating
the extra leakage and insuring that Reverse line pressure pressure will be
sufficient.
9 Provides a by-pass around the rear servo orifice so that the servo can release
quickly.
ECE (10) Allows the lockup clutch to used at WOT in 3rd gear by putting line pressure
from the 3-4 Timing Valve on the interlock area of the 2-3 shift valve, thereby
preventing a 3rd gear Lock-up to 2nd gear kickdown.
WJAUTOMATIC TRANSMISSION - 42RE 21 - 139
VALVE BODY (Continued)