1994 JEEP CHEROKEE check engine

30RH/32RH IN-VEHICLE SERVICE
INDEX
page page
Checking Fluid Level and Condition........... 96
Front Band Adjustment.................... 99
Gearshift Linkage Adjustment (YJ)............ 96
Governor and Park Gear Service............ 101
Oil Filter Replacement.................... 100
Park Interlock Cable Adjustment (XJ)......... 97
Park Lock Component Replacement......... 102
Park/Neutral Position Switch Service......... 103
Rear Band Adjustment.................... 99
Recommended Fluid...................... 96
Servicing Transmission Cooler Lines and Fittings. 106
Shift Cable Adjustment (XJ)................ 97
Speedometer Service.................... 103
Transmission Cooler Flow Testing........... 106
Transmission Cooler Reverse Flushing....... 105
Transmission Throttle Cable Adjustment (XJ/YJ) . 98
Valve Body Installation................... 101
Valve Body Removal..................... 100
Valve Body Service...................... 100
RECOMMENDED FLUID
The recommended and preferred fluid for 30RH/
32RH transmissions is Mopar ATF Plus, Type 7176.
Mopar Dexron II is acceptable but should only be
used when ATF Plus is not available.
Transmission fluid capacity is approximately 17
pints (7.9 liters). This is the approximate amount of
fluid required to fill the transmission and torque con-
verter after overhaul.
CHECKING FLUID LEVEL AND CONDITION
(1) Position vehicle on flat, level surface. This is
important in obtaining an accurate fluid level check.
(2) To avoid false readings, which could produce
under or over fill condition, do not check level until
fluid is at normal operating temperature.
(3) Shift transmission into Neutral.
(4) Apply parking brakes.
(5) Operate engine at curb idle speed.
WARNING: WHEN PERFORMING UNDERHOOD OP-
ERATIONS WITH THE ENGINE RUNNING, KEEP
YOUR HANDS WELL AWAY FROM HOT OR ROTAT-
ING ENGINE COMPONENTS. DO NOT WEAR
LOOSE ARTICLES OF CLOTHING WHICH COULD
BECOME ENTANGLED IN ENGINE COMPONENTS
OR ACCESSORIES.
(6) Shift transmission through all gear ranges and
back to Neutral (leave engine running).
(7) Clean exterior of dipstick cap and fill tube be-
fore removing transmission dipstick.
(8) Remove dipstick and inspect fluid level.
²Correct level is to FULL mark
²Acceptable level is between ADD and FULL marks
(9) Check fluid condition. Fluid should be dark to
light red in color and free of dirt or debris.
(10) If fluid is discolored or smells burned but
transmission operation was OK, check cooler flow,
flush cooler and lines and change fluid and filter.
Then road test again to confirm proper operation.(11) If fluid is black or dark brown, burned/turned
to sludge, contains large quantities of metal or fric-
tion material particles, transmission will need over-
haul. Especially if problems were evident during
road test and preliminary diagnosis. Fluid cooler
should also be flow tested and flushed if necessary.
GEARSHIFT LINKAGE ADJUSTMENT (YJ)
(1) Check linkage adjustment by starting engine in
Park and Neutral.
(2) Adjustment is OK if engine starts only in park
and Neutral. Adjustment is incorrect if engine starts
in one but not both positions.
(3) If engine starts in any position other than Park
or Neutral, or if engine will not start at all, park/
neutral position switch may be faulty.
(4) Shift transmission into Park.
(5) Raise vehicle.
(6) Check condition of shift rods, bellcrank, bell-
crank brackets and linkage bushings/grommets (Fig.
1). Tighten, repair, replace worn, damaged parts. Do
not attempt adjustment if linkage components are
worn or damaged.
(7) Loosen shift rod trunnion lock bolt or nut. Be
sure upper shift rod slides freely in trunnion (Fig. 1).
Also be sure shift rods and bellcrank rotate freely
and do not bind at any point.
(8) Verify that manual lever is in Park detent
(Fig. 1). Move lever all the way rearward to be sure
it is in Park.
(9) Check for positive engagement of park lock by
attempting to rotate propeller shaft. Shaft will not
turn when park pawl is engaged.
(10) Adjust shift rod trunnion to a obtain free pin
fit in bellcrank arm and tighten trunnion lock bolt or
nut. Prevent shift rod from turning while tightening
bolt or nut. Gearshift linkage lash must be elimi-
nated to obtain proper adjustment. Eliminate lash by
pulling downward on shift rod and pressing upward
on bellcrank.
21 - 96 30RH/32RH IN-VEHICLE SERVICEJ

(11) Confirm proper adjustment by starting engine
in Park and Neutral. Engine should start in these
positions only.If engine starts in any position
other than Park or Neutral, adjustment is incor-
rect or neutral switch is faulty.
(12) Lower vehicle and verify that steering lock op-
erates correctly.
SHIFT CABLE ADJUSTMENT (XJ)
(1) Shift transmission into Park.
(2) Raise vehicle.
(3) Release cable adjuster clamp to unlock cable
(Figs. 2 and 3). Clamp is at transmission end of ca-
ble.
(4) Unsnap cable from transmission cable bracket
(Figs. 2 and 3).
(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 (XJ)
(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.
Fig. 1 Gearshift Linkage (YJ)
Fig. 2 Shift Cable (XJ)
J30RH/32RH IN-VEHICLE SERVICE 21 - 97

condenser. The auxiliary cooler is a serviceable com-
ponent and can be repaired if necessary.
The main and auxiliary coolers should be thor-
oughly reverse flushed if a transmission failure
contaminates the fluid. Reverse flushing the cooler
and lines will prevent sludge and particles from
flowing back into the transmission after repair.
The same flushing procedure is used for main and
auxiliary coolers. Pressure equipment is preferred for
reverse flushing. However, reverse flushing can be
performed using hand operated equipment as de-
scribed in the following procedure.
REVERSE FLUSHING PROCEDURE
(1) Disconnect cooler lines at transmission. Refer
to Figure 21 for cooler line fitting identification.
Front fitting is outlet to cooler and rear fitting is in-
let from cooler.
(2) Position drain pan under cooler outlet line to
material flushed through cooler and lines.
(3) Reverse flush cooler using hand operated suc-
tion gun filled with mineral spirits. Insert gun nozzle
(or hose) into cooler inlet (return) line. Then force
mineral spirits through Line and cooler.
(4) Continue reverse flushing until fluid exiting in-
let (pressure) line is clear and free of debris/residue.
Replace radiator if fluid cannot be pumped
through cooler.
(5) Clear flushing materials from cooler 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.
(6) Pump one quart of fresh automatic transmis-
sion fluid through cooler and lines before reconnect-
ing cooler lines.
TRANSMISSION COOLER FLOW TESTING
The transmission main and auxiliary coolers
should be flow tested whenever a fluid overheat con-
dition is suspected. An overheat condition is indi-
cated when the fluid changes from the normal red, to
a dark orange, or brown color.
The same method of flow testing is used for both
coolers.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 fitting.
(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.
SERVICING TRANSMISSION COOLER LINES AND
FITTINGS
Fitting Types
The transmission cooler lines are attached with
quick disconnect fittings.
A flange on the cooler line serves as the sealing
mechanism. The wire retainer clip (Fig. 22), secures
the cooler line in the fitting by this flange. The clip
fits behind the flange to hold the line in place.
Three different fitting styles may be used. Type 1
fittings have the retainer clip exposed (Fig. 22). Type
2 fittings have the retainer clip and fitting body en-
cased in a shrink wrap material (Fig. 23). Type 3 fit-
tings have the retainer clip encased in a metal sleeve
crimped onto the fitting body (Fig. 24).
Fitting Release Tool
A release tool isrequiredto disconnect each of the
fitting types. A plastic tool is clipped directly to one
of the cooler lines on models with the type 2 and 3
fittings. This tool can also be used to disconnect type
1 fittings. The tool is needed to spread the wire re-
tainer clip in each fitting. The clip must be opened in
order to release the cooler line from the fitting.
Fig. 21 Identifying Transmission Cooler Lines
Fig. 22 Type 1 Quick Disconnect Fitting
21 - 106 30RH/32RH IN-VEHICLE SERVICEJ

(1) Lubricate converter drive hub and pump seal
with Mopar ATF Plus, or Dexron II transmission
fluid. Then install converter. Turn converter back
and forth to align drive slots in converter hub with
pump gear lugs. Be sure converter is fully seated in
pump (Fig. 5).
(2) Temporarily secure converter with C-clamp or
metal strap attached across converter housing.
(3) Position transmission on jack and secure it
with safety chains.
(4) Raise transmission and align converter with
drive plate.
(5) Move transmission forward. Then raise, lower
or tilt transmission to align converter housing with
engine block dowels.
(6) Install two converter housing lower attaching
bolts and tighten bolts to draw housing toward en-
gine.
(7) Install and tighten converter attaching bolts.
(8) Install and tighten bolts that attach transmis-
sion to engine (Fig. 6).
(9) Install crankshaft position sensor as follows:
CAUTION: Clearance between the sensor pickup
face and driveplate ring gear must be correctly es-
tablished before engine startup. A cardboard
spacer, attached to the sensor face, is used for thispurpose. Failure to establish correct clearance will
result in sensor breakage.
(a) Remove any remaining fragments of original
cardboard spacer from sensor pickup face.
Fig. 5 Checking Torque Converter Seating
Fig. 6 Transmission Attachment
21 - 110 30RH/32RH TRANSMISSION REMOVAL AND INSTALLATIONJ

(b) Align and install new spacer on sensor
pickup face. Spacer has adhesive backing so it will
adhere to sensor face.
(c) Insert sensor into housing until it just
touches ring gear teeth. Then install and tighten
sensor attaching bolt. Correct clearance is estab-
lished when spacer is peeled off by ring gear dur-
ing engine startup.
(10) Install transmission fill tube and O-ring (Fig.
6).
(11) Connect transmission cooler lines to fittings.
Refer to Figure 7 for cooler line identification.(12) Position support stand under transmission
and remove transmission jack.
(13) Install transfer case on transmission adapter.
Tighten attaching nuts to 41 Nzm (30 ft. lbs.) torque.
(14) Install rear crossmember and attach transmis-
sion rear support to crossmember.
(15) Connect vehicle speed sensor wires.
(16) Install inspection cover on converter housing.
(17) Install exhaust pipes and support brackets, if
removed.
(18) Install starter motor.
(19) Connect wires to park/neutral position switch.
(20) Connect gearshift and linkage and throttle ca-
ble.
(21) Connect transfer case shift linkage.
(22) Connect propeller shafts to transfer case
yokes.
(23) Connect front exhaust pipes and catalytic con-
verter support bracket bolts (if removed).
(24) Install skid plate, rear cushion and bracket, if
removed.
(25) Fill transfer case to bottom edge of fill plug
hole with Mopar Dexron II.
(26) Lower vehicle and fill transmission to correct
level with ATF Plus, type 7176 fluid.
(27) Install fan shroud and bolts (if removed).
(28) Check and adjust gearshift linkage if neces-
sary. Then check and adjust throttle cable if neces-
sary.
Fig. 7 Transmission Cooler Line Location And
Identification
J30RH/32RH TRANSMISSION REMOVAL AND INSTALLATION 21 - 111

(2) Verify transmission throttle cable operation.
Repair or replace cable if necessary.
(3) Check engine throttle operation. Operate accel-
erator pedal and observe injector throttle plate move-
ment. Adjust linkage if throttle plate does not reach
wide open position.
(4) Check transmission fluid level when fluid is at
normal operating temperature. Start engine. Shift
transmission through all gear ranges then back to
Neutral. Correct level is to Full or Add mark on dip-
stick with engine at curb idle speed.
(5) Check and adjust park/neutral position switch
if necessary.
(6) Check throttle position sensor adjustment and
operation. Adjust the sensor if necessary.
MANUAL SHIFTING TEST
(1) This test determines if problem is related to
mechanical or electrical component.
(2) Stop engine and disconnect transmission con-
trol module or module fuse.
(3) Road test vehicle. Shift transmission into each
gear range. Transmission should operate as follows:
²lock in Park
²back up in Reverse
²not move in Neutral
²provide first gear only with shift lever in 1-2 posi-
tion
²operate in third gear only with shift lever in 3 po-
sition
²operate in overdrive fourth gear in D position
(4) If transmission operates as described, proceed
to next step. However, if forward gear ranges were
difficult to distinguish (all feel the same), or vehicle
would not back up, refer to diagnosis charts. Do not
perform stall or time lag tests.
CAUTION: Do not overspeed the engine during the
next test step. Ease off the throttle and allow the
vehicle to slow before downshifting.
(5) Continue road test. Manually downshift trans-
mission from D to 3, and from 3 to 1-2 position. Then
manually upshift transmission through forward
ranges again.
(6) If transmission operation is OK, perform stall,
time lag and pressure tests. If transmission shifting
problem is encountered, refer to diagnosis charts.
(7) If a problem still exists, continue testing with
DRB II scan tool.
HYDRAULIC PRESSURE TEST
PRESSURE TEST PROCEDURE
(1) Connect pressure test gauge to test port on pas-
senger side of transmission. Use Adapter 7554 to con-
nect gauge. Be sure test gauge has minimum
capacity of 300 psi (2100 kPa).(2) Be sure transmission fluid is at normal operat-
ing temperature.
(3) Apply parking brakes and block wheels.
WARNING: DO NOT ALLOW ANYONE TO STAND AT
THE FRONT OR REAR OF THE VEHICLE WHILE
PERFORMING THE FOLLOWING STEPS IN THE
PRESSURE TEST.
(4) Check and adjust engine curb idle speed.
(5) Apply service brakes.
(6) Shift transmission into D range and note line
pressure with engine at curb idle speed. Pressure
should be 61-to-70 psi (421-to-481 kPa).
(7) Press accelerator pedal to wide open throttle
position and note line pressure. Pressure should be
173-to-209 psi (1196-to-1442 kPa).
CAUTION: Do not maintain wide open throttle for
more than three or four seconds at a time.
(8) Shift transmission into Reverse and note line
pressure with engine at curb idle speed. Pressure
should be 75-to-90 psi (519-to-618 kPa).
(9) Press accelerator to wide open throttle position
and note line pressure in Reverse. Pressure should
be 213-to-263 psi (1471-to-1814 kPa).
CAUTION: Do not maintain wide open throttle for
more than three or four seconds at a time.
(10) If line pressure is not within specifications,
adjust transmission throttle cable and repeat pres-
sure test.
Fig. 27 Pressure Test Gauge Connection
21 - 168 AW-4 TRANSMISSION DIAGNOSISJ

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