1994 JEEP CHEROKEE engine

can be caused by leaking hydraulic circuits or stick-
ing valves. Unless the problem is an obvious one, do
not remove and disassemble the transmission until
hydraulic and air pressure tests have been per-
formed.
HYDRAULIC PRESSURE TEST
Hydraulic test pressures range from a low of one
psi (6.895 kPa) governor pressure, to 300 psi (2068.5
kPa) at the rear servo pressure port in reverse.
Use 100 psi Pressure Gauge C-3292 to check pres-
sure at the accumulator, front servo, governor and
fluid cooler line. Use 300 psi Gauge C-3293 to check
pressure at the rear servo. The 300 psi gauge can be
used at any other port when more than one gauge is
required for testing.
PRESSURE TEST PORT LOCATIONS
There are pressure test ports at the accumulator,
front servo, rear servo and governor.
Line pressure is checked at the accumulator port
on the right side of the case (Fig. 4). The front servo
release pressure port is at the right side of the case
just behind the filler tube opening (Fig. 4).
The rear servo pressure port is at the right rear of
the transmission case (Fig. 5).
On4x2models, the governor pressure port is at
the left side of case at the transmission rear (Fig. 5).
On4x4transmissions, the test port is in the driver
side of the adapter housing (Fig. 6).
PRESSURE TEST PROCEDURE
Connect a tachometer to the engine. Position the
tachometer so it can be observed from under the ve-
hicle. Raise the vehicle on hoist that will allow the
wheels to rotate freely.
Test One-Transmission In 1 Range
This test checks pump output, pressure regula-
tion, and condition of the rear clutch and rear
servo circuits. Use 300 psi Test Gauge C-3293 for
this test
(1) Connect test gauges to line pressure and rear
servo ports (Figs. 4-6).Be sure pressure test gauge
is connected to rear servo port.
(2) Disconnect throttle and gearshift rods at trans-
mission.
(3) Start and run engine at 1000 rpm.
(4) Move valve body selector lever forward into 1
range.
(5) Read pressures on both gauges as transmission
throttle lever is moved from full forward to full rear-
ward position.
(6) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually in-
crease to 90-96 psi (620-662 kPa) as lever is moved
rearward.
(7) Rear servo pressure should be same as line
pressure within 3 psi.
Test Two-Transmission In 2 Range
This test checks pump output and pressure
regulation. Use 100 psi Test Gauge C-3292 for
this test.
(1) Connect test gauge to line pressure port (Fig.
4).
(2) Start and run engine at 1000 rpm.
(3) Move valve body selector lever one detent rear-
ward from full forward position. This is 2 range.
(4) Move transmission throttle lever from full for-
ward to full rearward position and read pressure at
both gauges.
Fig. 4 Front Servo And Line Pressure Test Ports
Fig. 5 Rear Servo And Governor Pressure Test
Ports (4 x 2 Transmission)
Fig. 6 Governor Pressure Test Port (4 x 4
Transmission)
J30RH/32RH TRANSMISSION DIAGNOSIS 21 - 71

(5) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually in-
crease to 90-96 psi (620-662 kPa) as lever is moved
rearward.
Test Three-Transmission In D Range
This test checks pressure regulation and con-
dition of the front and rear clutch circuits.
Both test gauges are required for this test.
(1) Connect one test gauge to line pressure port
and other gauge to front servo pressure port (Fig. 4).
Either gauge can be used at either port.
(2) Start and run engine at 1600 rpm.
(3) Move selector lever two detents rearward from
full forward position. This is D range.
(4) Read pressures on both gauges as transmission
throttle lever is moved from full forward to full rear-
ward position.
(5) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually in-
crease as lever is moved rearward.
(6) Front servo is pressurized only in D range and
should be same as line pressure within 3 psi (21
kPa), up to downshift point.
Test Four-Transmission In Reverse
This test checks pump output, pressure regu-
lation and the front clutch and rear servo cir-
cuits. Use 300 psi Pressure Test Gauge C-3293
for this test.
(1) Connect pressure test gauge to rear servo port
(Fig. 5).
(2) Start and run engine at 1600 rpm for test.
(3) Move valve body selector lever four detents
rearward from full forward position. This is Reverse
range.
(4) Move throttle lever all way forward then all the
way rearward and note gauge readings.
(5) Pressure should be 145 - 175 psi (1000-1207
kPa) with lever forward and increase to 230 - 280 psi
(1586-1931 kPa) as lever is moved rearward.
Test Five-Governor Pressure
This test checks governor operation by mea-
suring governor pressure response to changes
in engine speed. It is usually not necessary to
check governor operation unless shift speeds
are incorrect or if the transmission will not
shift up or down. Use 100 psi Pressure Test
Gauge C-3292 for this test.
(1) Connect test gauge to governor pressure port
(Figs. 5 and 6).
(2) Move selector lever to D range.
(3) Apply service brakes. Start and run engine at
curb idle speed and note pressure. At idle and with
wheels stopped, pressure should be zero to 1-1/2 psi
maximum. If pressure exceeds this figure, governor
valve or weights are sticking open.(4) Slowly increase engine speed and observe
speedometer and pressure test gauge. Governor pres-
sure should increase in proportion to vehicle speed
(approximately 1 psi for every 1 mph shown on
speedometer).
(5) Governor pressure rise should be smooth and
drop back to 0 to 1-1/2 psi when throttle is closed
and wheels are stopped.
(6) Compare results of pressure tests with analysis
chart (Fig. 7).
CONVERTER STALL TEST
Stall testing involves determining maximum engine
rpm obtainable at full throttle with the rear wheels
locked and the transmission in D range. This test
checks the holding ability of the converter overrun-
ning clutch and both of the transmission clutches.
When stall testing is completed, refer to the Stall
Speed Specifications chart and Stall Speed Diagnosis
guides.
WARNING: NEVER ALLOW ANYONE TO STAND IN
FRONT OF THE VEHICLE DURING A STALL TEST.
ALWAYS BLOCK THE FRONT WHEELS AND APPLY
THE SERVICE AND PARKING BRAKES DURING THE
TEST.
Fig. 7 Pressure Test Analysis Chart
21 - 72 30RH/32RH TRANSMISSION DIAGNOSISJ

STALL TEST PROCEDURE
(1) Connect tachometer to engine.
(2) Check and adjust transmission fluid level.
(3) Start and run engine until transmission fluid
reaches normal operating temperature.
(4) Block front wheels.
(5) Fully apply service and parking brakes.
(6) Open throttle completely for no more than five
seconds and record maximum engine rpm registered
on tachometer.
CAUTION: Stall testing causes a rapid increase in
transmission fluid temperature. Do not hold the
throttle open any longer than five seconds. If more
than one stall test is required, run the engine at
1000 rpm with the transmission in Neutral for at
least 20 seconds to cool the fluid.
(7) If engine speed exceeds maximum shown in
stall speed chart, release accelerator immediately.
This indicates that transmission clutch slippage is
occurring.
(8) Shift transmission into Neutral. Run engine for
20 seconds to cool fluid. Then stop engine, shift
transmission into Park and release brakes.
(9) Stall speeds should be in 1700-2000 rpm range.
(10) Refer to Stall Test Diagnosis.
STALL TEST DIAGNOSIS
Stall Speed Too High
If the stall speed exceeds specifications by more
than 200 rpm, transmission clutch slippage is indi-
cated.
Stall Speed Too Low
Low stall speeds with a properly tuned engine in-
dicate a torque converter overrunning clutch prob-
lem. The condition should be confirmed by road
testing prior to converter replacement.
The converter overrunning clutch is slipping when
stall speeds are 250 to 350 rpm below specified min-
imum. And when the vehicle operates properly at
highway speeds but has poor low speed acceleration.
Stall Speed Normal
If stall speeds are normal but abnormal throttle
opening is required to maintain highway speeds, the
converter overrunning clutch is seized and the torque
converter must be replaced.
Converter Noise During Test
A whining noise caused by fluid flow is normal
during a stall test. However, loud metallic noises in-
dicate a damaged converter. To confirm that noise is
originating from the converter, operate the vehicle at
light throttle in Drive and Neutral on a hoist and lis-
ten for noise coming from the converter housing.
AIR PRESSURE TEST
Air pressure testing can be used to check clutch
and band operation with the transmission either in
the vehicle, or on the work bench as a final check af-
ter overhaul.
Air pressure testing requires that the oil pan and
valve body be removed from the transmission.
The servo and clutch apply passages are shown in
Figure 8.
Air Test Procedure
(1) Place one or two fingers on the clutch housing
and apply air pressure through front clutch apply
passage (Fig. 8). Piston movement can be felt and a
soft thud heard as the clutch applies.
(2) Place one or two fingers on the clutch housing
and apply air pressure through rear clutch apply pas-
sage (Fig. 8). Piston movement can be felt and a soft
thud heard as the clutch applies.
(3) Apply air pressure to the front servo apply pas-
sage. The servo rod should extend and cause the
band to tighten around the drum. Spring tension
should release the servo when air pressure is re-
moved.
(4) Apply air pressure to the rear servo apply pas-
sage. The servo rod should extend and cause the
band to tighten around the drum. Spring tension
should release the servo when air pressure is re-
moved.
CONVERTER HOUSING LEAK DIAGNOSIS
Two items must be established when diagnosing
leaks from the converter housing area. First, it must
be verified that a leak condition actually exists. And
second, the true source of the leak must be deter-
mined.
Fig. 8 Air Pressure Test Passages
J30RH/32RH TRANSMISSION DIAGNOSIS 21 - 73

Some suspected converter housing fluid leaks may
not be leaks at all. Residual fluid in the housing, or
excess fluid spilled during factory fill or refill after
repair can be mistaken for a leak. In addition, a rear
main seal leak can also be mistaken for a pump seal
leak if care is exercised.
Converter housing leaks have several potential
sources. Through careful observation, a leak source
can be identified before removing the transmission
for repair.
Pump seal leaks tend to move along the drive hub
and onto the rear of the converter. Pump O-ring or
pump body leaks follow the same path as a seal leak
(Fig. 9).
Pump vent or pump attaching bolt leaks are gener-
ally deposited on the inside of the converter housing
and not on the converter itself (Fig. 9).
Pump seal or gasket leaks usually travel down the
inside of the converter housing.
Front band lever pin plug leaks are generally de-
posited on the housing and not on the converter.
LEAK DIAGNOSIS PROCEDURE
(1) Raise the rear of the vehicle and allow accumu-
lated fluid to drain out of the converter housing.
(2) Check and adjust the transmission fluid level.
(3) Raise the vehicle. Remove the converter hous-
ing dust cover and wipe as much fluid as possible
from the converter housing.
(4) Fabricate a test probe (Fig. 10). Then attach
the probe to the converter housing with one of the
dust shield bolts (Fig. 10).
(5) Have a helper run the engine at 2500 rpm
(with the transmission in Neutral) for two minutes;
then stop the engine.
(6) Inspect the test probe and converter housing. If
a leak is evident, note the color of the fluid. Trans-
mission fluid is red. Engine oil ranges in color from
brown to green, or to black when the oil is dirty.(7) If the probe upper surface is dry, the converter
and seal are not at fault. A path of fluid across the
probe upper surface indicates a converter or seal
leak. Fluid leakingunderthe probe is coming from
the pump housing area (Fig. 11).
(8) Fluid leaking under the probe could be from
the: pump seal and/or bushing, pump vent, kickdown
lever shaft access plug, pump bolts, or porous spots
in the pump body or transmission case (Fig. 11).
(9) If porous spots in the transmission case or
pump body are the suspected leak source, pressurize
the transmission as described in Leak Testing With
Air Pressure.
LEAK TESTING WITH AIR PRESSURE
This test involves closing off the transmission
openings and pressurizing the transmission to 8 psi
with Air Pump Tool 7700. A soapy water solution is
applied to suspected leak points before and during
the pressure test. Leaks will be indicated by the
presence of air bubbles coming through the solution.
Some transmission openings such as the fill tube
and front cooler line fitting can be closed off with a
rubber plug or similar device. Plugs can secured with
wire or duct tape.
Fig. 9 Typical Converter Housing Leak Paths
Fig. 10 Leak Test Probe
Fig. 11 Pump Area Inspection Points
21 - 74 30RH/32RH TRANSMISSION DIAGNOSISJ

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

THROTTLE CABLE ADJUSTMENT
PROCEDURE
Cable adjustment is performed entirely in the
engine compartment. It is not necessary to raise
the vehicle for access to any other components.
(1) Shift transmission into Park and shut engine
off.
(2) Press cable release button (Fig. 5).
(3) Push cable conduit back into cable adjuster
body as far as possible (Fig. 6).
(4) Rotate throttle body lever to wide open throttle
position. Cable will ratchet to correct adjustment
point as lever is rotated (Fig. 6).
FRONT BAND ADJUSTMENT
The front band adjusting screw is located on the
left side of the transmission case above the manual
valve and throttle valve levers.
(1) Raise vehicle.
(2) Loosen band adjusting screw locknut. Then
back locknut off 4-5 turns.
(3) Clean adjusting screw threads with Mopar rust
penetrant if necessary. Then lubricate threads withMopar spray lube or petroleum jelly. Be sure screw
turns freely in case. This is necessary for accurate
adjustment.
(4) Tighten band adjusting screw to 8 Nzm (72 in.
lbs.) torque with inch-pound torque wrench.If
Adapter Extension C-3705 is needed in order to
reach adjusting screw, tighten screw to only 5-6
Nzm (47-50 in. lbs.) torque (Fig. 7).
(5) Back off front band adjusting screw as follows:
²On 30RH (2.5L), back adjusting screw off
2-1/2 turns
²On 32RH (4.0L), back adjusting screw off
2-1/4 turns
(6) Hold adjuster screw in position and tighten
locknut to 41 Nzm (30 ft. lbs.) torque.
(7) Lower vehicle.
REAR BAND ADJUSTMENT
The transmission oil pan must be removed for ac-
cess to the rear (low-reverse) band adjusting screw.
(1) Raise vehicle.
(2) Remove transmission oil pan and drain fluid.
(3) Loosen band adjusting screw locknut 5-6 turns.
Be sure adjusting screw turns freely in lever.
(4) Tighten adjusting screw as follows: On 32Rh
transmission, tighten screw to 8 Nzm (72 in. lbs.)
torque. On 30RH transmission, tighten adjusting
screw to 5 Nzm (41 in. lbs.) torque (Fig. 8).
(5) Back off rear band adjusting screw as follows:
²On 30RH (2.5L), back adjusting screw off 7
turns
²On 32RH (4.0L), back adjusting screw off 4
turns
(6) Hold adjusting screw in place and tighten lock-
nut to 34 Nzm (25 ft. lbs.) torque.
(7) Position new gasket on oil pan and install pan
on transmission. Tighten pan bolts to 17 Nzm (150 in.
lbs.) torque.
(8) Lower vehicle and refill transmission with rec-
ommended fluid.
Fig. 5 Throttle Valve Cable Components
Fig. 6 Throttle Valve Cable Adjustment
Fig. 7 Front Band Adjustment
J30RH/32RH IN-VEHICLE SERVICE 21 - 99

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