1994 JEEP CHEROKEE engine

PRESSURE TEST ANALYSIS
If pressures in D and Reverse are higher than
specified, check for the following:
²throttle cable loose, worn, binding or out of adjust-
ment
²throttle valve, downshift plug, throttle cam, or pri-
mary regulator valve are sticking, worn or damaged
If pressures in D and Reverse are lower than spec-
ified, check for following:
²throttle cable loose, worn, binding or out of adjust-
ment
²throttle valve, downshift plug, throttle cam stick-
ing, worn or damaged
²primary regulator valve sticking, worn, or dam-
aged
²oil pump gears or housing worn or damaged
²overdrive clutch worn or damaged
If pressures are low in D range only, check for fol-
lowing:
²forward clutch worn or damaged
²fluid leakage in D range circuit (component seal
and O-rings)
If pressures are low in Reverse only, check for fol-
lowing:
²shift cable and manual valve out of adjustment
²fluid leakage in reverse circuit (component seal
and O-rings)
²direct clutch worn or damaged
²first/reverse brake worn or damaged
TORQUE CONVERTER STALL TEST
Stall testing checks the holding ability of the trans-
mission clutches and brakes and of the torque con-
verter stator overrunning clutch.
(1) Be sure transmission fluid is at normal operat-
ing temperature.
(2) Connect tachometer to engine. Position tachom-
eter so it can be viewed from drivers seat.
(3) Apply parking brakes and block wheels.
(4) Apply and hold service brakes.
(5) Shift transfer case into 2H position. On models
with NP249 transfer case, leave transfer case in 4H
position.
(6) Start engine.
WARNING: DO NOT ALLOW ANYONE TO STAND AT
THE FRONT OR REAR OF THE VEHICLE DURING
THE TEST.
(7) Shift transmission into D range.
(8) Press accelerator pedal to wide open throttle
position and note maximum engine rpm. Stall speed
should be 2100 to 2400 rpm in D range.
CAUTION: Do not maintain wide open throttle for
more than 3-4 seconds at a time.(9) Release throttle and shift transmission into
Neutral. Allow transmission fluid to cool for 15-20
seconds.
(10) Shift transmission into Reverse.
(11) Press accelerator down to wide open throttle
position and note maximum engine rpm. Stall speed
should be 2100-to-2400 rpm in Reverse.
STALL SPEED TEST ANALYSIS
If engine rpm is lower than specified in D and Re-
verse, check for the following:
²engine output/performance insufficient
²stator overrunning clutch in torque converter not
holding if engine speed was 1500 rpm or less.
If stall speed in D range is higher than specified,
check for the following:
²line pressure low
²forward clutch slipping
²No. 2 one-way clutch not holding
²overdrive one-way clutch not holding
If stall speed in Reverse was higher than specified,
check for the following:
²line pressure low
²direct clutch slipping
²first/ reverse brake slipping
²overdrive one-way clutch not holding
If stall speeds were higher than specified in both D
and Reverse, check for the following:
²low fluid level
²line pressure low
²overdrive one-way clutch not holding
TIME LAG TEST
This test checks general condition of the overdrive
clutch, forward clutch, rear clutch and first/reverse
brake. Condition is indicated by the amount of time
required for clutch/brake engagement with the en-
gine at curb idle speed. Engagement time is mea-
sured for D and Reverse positions. A stop watch is
recommended for test accuracy.
TEST PROCEDURE
(1) Check and adjust transmission fluid level if
necessary.
(2) Bring transmission to normal operating tem-
perature.
(3) Apply parking brakes and turn off air condi-
tioning unit.
(4) Shift transfer case into 2H range. On models
with NP249 transfer case, leave transfer case in 4H
range.
(5) Start engine and check curb idle speed. Adjust
speed if necessary. Curb idle must be correct to en-
sure accurate test results.
(6) Shift transmission into Neutral and set stop
watch.
(7) During following test steps, start stop watch as
soon as shift lever reaches D and Reverse ranges.
JAW-4 TRANSMISSION DIAGNOSIS 21 - 169

(8) Tighten switch adjusting bolt to 13 Nzm(9ft.
lbs.) torque.
(9) Bend at least two washer lock tabs over switch
attaching nut to secure it.
(10) Connect shift linkage rod to shift lever on left
side of case.
(11) Connect switch wires to harness and lower ve-
hicle.
(12) Check switch operation. Engine should start
in Park and Neutral only.
TRANSMISSION VALVE BODY SOLENOIDS
SOLENOID REMOVAL
(1) Remove transmission oil pan drain plug and
drain fluid.
(2) Remove pan bolts and remove oil pan.
(3) Remove oil screen bolts and remove screen (Fig.
7) and gasket. Discard the gasket.(4) Disconnect solenoid wire connector (Fig. 8).
(5) If all solenoids are being removed, mark or tag
wires for assembly reference before disconnecting
them.
(6) Remove bolt attaching solenoids to valve body
and remove solenoids (Fig. 9). Do not allow any valve
body components to fall out when solenoids are re-
moved.
(7) Clean oil filter and pan with solvent and dry
with compressed air.
(8) Remove old sealer material from oil pan and
transmission case.
Solenoid Testing
Test solenoid resistance with an ohmmeter. Con-
nect the ohmmeter leads to the solenoid mounting
bracket and to the solenoid wire terminal (Fig. 10).
Fig. 8 Solenoid Wire Connectors
Fig. 9 Transmission Valve Body Solenoids
Fig. 6 Park/Neutral Position Switch Adjustment
Fig. 7 Oil Screen Removal/Installation
JAW-4 IN-VEHICLE SERVICE 21 - 175

(3) Tighten adaptor housing bolts to 34 Nzm (25 ft.
lbs.) torque.
(4) Install components removed to gain access to
rotor and drive gear.
THROTTLE POSITION SENSOR (TPS) SERVICE
A separate throttle position sensor is used for au-
tomatic transmission applications. The sensor is at-
tached to the base of the throttle body. Refer to
Group 14 for TPS service and adjustment.
TRANSMISSION THROTTLE CABLE REPLACEMENT
THROTTLE CABLE REMOVAL
(1) In engine compartment, disconnect cable from
throttle linkage. Then compress cable mounting ears
and remove cable from engine bracket (Fig. 41).
(2) Raise vehicle.
(3) Remove transmission oil pan.
(4) Disengage cable from throttle valve cam (Fig.
42).
Fig. 41 Transmission Throttle Cable Attachment
Fig. 40 Removing Speed Sensor Rotor
Fig. 39 Removing/Installation Speedometer Drive
Gear
21 - 184 AW-4 IN-VEHICLE SERVICEJ

(5) Remove cable bracket bolt and remove cable
and bracket from case (Fig. 43).
(6) Remove and discard cable seal.
THROTTLE CABLE INSTALLATION
(1) Lubricate and install new seal on cable.
(2) Insert cable in transmission case.
(3) Attach cable to throttle cam (Fig. 42).
(4) Install cable bracket on case and tighten at-
taching bolt to 10 Nzm (7 ft-lbs) torque (Fig. 43).
(5) Remove old sealer material from oil pan and
transmission case. Clean oil pan with solvent and dry
it with compressed air.(6) Apply bead of Mopar or Loctite 599 sealer to oil
pan sealing surface. Sealer bead should be at least 3
mm (1/8 in.) wide. Then install pan and tighten pan
bolts to 7 Nzm (65 in. lbs.) torque.
(7) Install new gasket on oil pan drain plug. Install
and tighten plug to 20 Nzm (15 ft. lbs.) torque.
(8) Connect cable to engine bracket and throttle
linkage.
(9) Fill transmission with Mopar Mercon.
(10) Adjust the cable as described in cable adjust-
ment procedure.
TRANSMISSION THROTTLE CABLE ADJUSTMENT
(1) Shift transmission into Park, shut engine off
and raise hood.
(2) Press cable release button (Fig. 44).
(3) Push cable conduit back into cable sheath as
far as possible (Fig. 45).
(4) Rotate lever on throttle body to wide open
throttle position. Cable will ratchet to correct adjust-
ment point as lever is rotated (Fig. 45).
Fig. 42 Removing/Installing Transmission Throttle
Cable
Fig. 43 Removing/Installing Transmission Throttle
Cable And Bracket
Fig. 44 Throttle Cable Components
Fig. 45 Throttle Cable Adjustment
JAW-4 IN-VEHICLE SERVICE 21 - 185

SHIFT CABLE ADJUSTMENT
(1) Shift transmission into Park.
(2) Raise vehicle.
(3) Release cable adjuster clamp to unlock cable
(Figs. 46 and 47). Clamp is at transmission end of ca-
ble.
(4) Unsnap cable from transmission cable bracket
(Figs. 46 and 47).
(5) Move transmission shift lever fully rearward to
Park detent. Lever is on manual valve shaft at driver
side of case.
(6) Verify positive engagement of park lock by at-
tempting to rotate propeller shaft. Shaft will not ro-
tate when park lock is engaged.
(7) Snap cable into cable bracket.
(8) Lock shift cable by pressing cable adjuster
clamp down until it snaps into place.
(9) Check engine starting. Engine should start only
in Park and Neutral.
(10) Lower vehicle.
PARK INTERLOCK CABLE ADJUSTMENT
(1) Shift transmission into Park.
(2) Turn ignition switch to Lock position.
(3) Remove shift lever bezel and console screws.
Raise bezel and console for access to cable.
(4) Pull cable lock button up to release cable (Fig.
47).
(5) Pull cable forward. Then release cable and
press cable lock button down until it snaps in place.
(6) Check adjustment as follows:(a) Check movement of release shift handle but-
ton (floor shift) or release lever (column shift). You
should not be able to press button inward or move
column lever.
(b) Turn ignition switch to On position.
(c) Press floor shift lever release button or move
column lever. Then shift into Neutral. If cable ad-
justment is correct, ignition switch can not be
turned to Lock position. Perform same check with
transmission in D range.
(7) Move shift lever back to Park and check igni-
tion switch operation. You should be able to turn
switch to Lock position and shift lever release button/
lever should not move.
Fig. 46 Shift Cable
Fig. 47 Park Lock Cable Attachment (XJ)
21 - 186 AW-4 IN-VEHICLE SERVICEJ

TRANSMISSION COOLER SERVICE
Main Cooler
The transmission main cooler is located in the ra-
diator. The main cooler can be flushed when neces-
sary, however, the cooler is not a repairable
component. If the cooler is damaged, plugged, or
leaking, the radiator will have to be replaced.
Auxiliary Cooler
The auxiliary cooler is mounted in front of the ra-
diator at the driver side of the vehicle (Fig. 48). The
cooler can be flushed when necessary, while mounted
in the vehicle. The cooler can also be removed for ac-
cess, repair, or replacement as needed.
The main and auxiliary coolers should both be
flushed whenever a transmission or converter clutch
malfunction generates sludge, debris, or particles of
clutch friction material.
Cooler Service
The main cooler (and radiator) and the auxiliary
cooler can be removed for service or access to other
components. Auxiliary cooler removal requires that
the front bumper and radiator support be removed
for access to the cooler lines and attaching bracket.
REVERSE FLUSHING MAIN AND AUXILIARY
COOLERS AND COOLER LINES
Reverse flushing the cooler and lines will prevent
sludge and particles from flowing back into the
transmission after repair. The flushing procedure ap-
plies to standard (in-radiator) coolers and auxiliary
coolers equally.
Pressure equipment is preferred for reverse flush-
ing. However, reverse flushing can be performed us-
ing hand operated equipment as described in the
following procedure.
(1) Disconnect cooler lines at transmission and at
auxiliary cooler (Figs. 48 and 49).
(2) Position drain pan under cooler line to catch
material flushed through coolers and lines.
(3) Reverse flush each cooler using hand operated
suction gun filled with mineral spirits. Insert gun
nozzle (or hose) into cooler inlet (return) line. Then
force mineral spirits through into line and through
cooler.(4) Continue reverse flushing until fluid exiting in-
let (pressure) line is clear and free of debris/residue.
(5) Replace radiator if fluid cannot be pumped
through main cooler. Replace auxiliary cooler if leaks
are evident, or if fluid cannot be pumped through it.
(6) Clear flushing materials from coolers and lines
with short pulses of compressed air. Insert air gun
nozzle into cooler inlet (return) line and continue
short pulses of air until all fluid is cleared from
cooler and lines.
(7) Pump one quart of fresh automatic transmis-
sion fluid through cooler and lines before reconnect-
ing cooler lines.
FLOW TESTING TRANSMISSION MAIN
COOLER
Cooler flow is checked by measuring the amount of
fluid flow through the cooler in a 20 second time pe-
riod. The test is performed with the engine running
and transmission in neutral. Fluid is then pumped
through the cooler by the transmission oil pump.
(1) Disconnect cooler inlet line at transmission fit-
ting.
(2) Securely attach hose to end of inlet line and po-
sition line in a one quart test container.
(3) Add extra quart of fluid to transmission.
(4) Use stopwatch to check flow test time.
(5) Shift transmission into neutral and set parking
brake.
(6) Start and run engine at curb idle speed and im-
mediately note cooler flow. Approximately one quart
of fluid should flow into test container in 20 second
period.
(7) If cooler flow is intermittent, flows less than
one quart in 20 seconds, or does not flow at all,
cooler is faulty and must be replaced.
TRANSMISSION COOLER LINE FITTINGS
Quick disconnect fittings are used at the transmis-
sion cooler line connections. The fitting seals and
guides are serviceable.
Replace the seals and guides whenever the fittings
exhibit leakage, or will not properly snap into place.
JAW-4 IN-VEHICLE SERVICE 21 - 187

AW-4 TRANSMISSION REMOVAL AND INSTALLATION
INDEX
page page
Oil Pump Seal Replacement............... 189
Torque Converter Stator Clutch Inspection..... 189Transmission and Torque Converter Installation . 190
Transmission and Torque Converter Removal . . 189
TRANSMISSION AND TORQUE CONVERTER
REMOVAL
(1) Raise vehicle.
(2) Drain transmission fluid and reinstall oil pan
drain plug.
(3) Remove upper half of transmission fill tube
(Fig. 50).
(4) Disconnect cooler lines at transmission. Cooler
lines have quick-disconnect fittings. Press fitting re-
lease tabs and pull cooler lines and fittings out of
case or use Special Tool 7555 to disconnect them.
(5) Support engine with safety stand and support
transmission with jack.
(6) Disconnect transmission and transfer case shift
linkage.
(7) Remove necessary exhaust components.
(8) Disconnect vehicle speed sensor wires
(9) Mark position of front and rear propeller shafts
for alignment reference. Then remove shafts from ve-
hicle.
(10) Remove rear crossmember.
(11) Disconnect transmission shift cable at trans-
mission. Then disconnect transmission throttle valve
cable at engine.(12) Disconnect necessary vacuum and fluid hoses.
(13) Remove transfer case from transmission.
(14) Disconnect and remove crankshaft position
sensor.
CAUTION: The crankshaft position sensor can be
damaged if the sensor is still in place when the
transmission is removed. To avoid damage, remove
the sensor before transmission removal.
(15) Remove starter motor.
(16) Remove bolts attaching converter to drive
plate.
(17) Remove bolts attaching converter housing to
engine.
(18) Secure transmission to jack with safety
chains.
(19) Pull transmission rearward for access to con-
verter. Then secure converter in pump with C-clamp
or strap bolted to converter housing.
(20) Remove transmission from under vehicle.
(21) Remove torque converter if converter or oil
pump seal are to be serviced.
TORQUE CONVERTER STATOR CLUTCH
INSPECTION
(1) Insert Rotating Tool 7547 into converter hub
and seat tool in one-way clutch (Fig. 51).
(2) Insert Stopper Tool 7548 in one converter hub
notch and into outer race of rotating tool.
(3) Turn rotating tool clockwise. Converter clutch
should rotate freely and smoothly. Less than 2.5 Nzm
(22 in. lbs.) of torque should be required to rotate
clutch in clockwise direction.
(4) Turn rotating tool in counterclockwise direction.
Converter clutch should lock.
(5)
Replace converter if clutch binds or will not lock.
OIL PUMP SEAL REPLACEMENT
(1) Remove converter.
(2) Remove old seal. Use blunt punch to collapse
seal and pry seal out of pump housing. Do not
scratch or damage seal bore.
(3) Lubricate lip of new seal with Mopar Mercon
transmission fluid and install seal in pump with tool
7549 (Fig. 52).
(4) Lubricate converter drive hub with Mopar Mer-
con transmission fluid.
Fig. 50 Two-Piece Transmission Fill Tube
JAW-4 TRANSMISSION REMOVAL AND INSTALLATION 21 - 189

(5) Align and install converter in oil pump.
TRANSMISSION AND TORQUE CONVERTER
INSTALLATION
(1) Mount transmission on transmission jack. Then
secure transmission to jack with safety chains.
(2) Lubricate converter drive hub and oil pump
seal lip with Mopar Mercon transmission fluid. Then
install converter. Be sure converter is fully seated in
oil pump gears before proceeding. Hold converter in
place with C-clamp or strap attached to converter
housing.
(3) Align and position transmission and converter
on engine.
(4) Remove clamp or strap used to hold torque con-
verter in place.
(5) Move transmission forward seat and it on en-
gine. Be sure torque converter hub is fully seated.
(6)
Install converter housing-to-engine bolts (Fig.
53).
(7) Install converter-to-drive plate bolts.
(8) Install and connect starter motor.
(9) Install and connect crankshaft position sensor.
(10) Install transfer case on transmission. Tighten
transfer case attaching nuts to 41 Nzm (30 ft. lbs.)
torque
(11) Connect transfer case shift linkage and vac-
uum hoses.
(12) Connect exhaust components.
(13) Install rear crossmember and remove jack
used to support transmission assembly.
(14) Connect speed sensor wire harness to sensor.
(15) Connect wire harness to park/neutral position
switch.
(16) Align and connect front and rear propeller
shafts.
Fig. 51 Checking Operation Of Torque Converter
Stator One-Way Clutch
Fig. 52 Installing Oil Pump Seal
21 - 190 AW-4 TRANSMISSION REMOVAL AND INSTALLATIONJ