1994 JEEP CHEROKEE automatic transmission

30RH/32RH AUTOMATIC TRANSMISSION
INDEX
page page
General Information....................... 66
Parts Interchangeability.................... 66
Recommended Fluid...................... 66
Specifications and Band Adjustments......... 66Torque Converter........................ 66
Transmission Application................... 66
Transmission Controls and Components....... 66
Transmission Identification.................. 66
GENERAL INFORMATION
TRANSMISSION APPLICATION
Chrysler 30RH and 32RH automatic transmissions
are used in XJ/YJ models. Both transmissions are
three speed, automatics with a gear-type oil pump,
two clutches and bands and a planetary gear system
(Fig. 1). The 30RH is used with 2.5L engines and the
32RH is used with 4.0L engines.
TORQUE CONVERTER
A three element, torque converter is used for all
applications. The converter consists of the impeller,
stator, and turbine.
The converter used with all 30RH/32RH transmis-
sions is equipped with a converter clutch. The clutch
is engaged by an electrical solenoid and mechanical
clutch module on the valve body. The solenoid is op-
erated by the powertrain control module.
The impeller is connected to the engine crankshaft
through the front cover which is welded to the impel-
ler. The turbine is splined to the transmission input
shaft and the stator is splined to the transmission re-
action shaft.
The torque converter is a welded assembly and is
not a repairable component. The converter is serviced
as an assembly.
RECOMMENDED FLUID
The recommended (and preferred) fluid for 30RH/
32RH transmissions is Mopar ATF Plus, Type 7176.
Mopar Dexron II can be used but only if 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.
TRANSMISSION IDENTIFICATION
The transmission identification numbers are
stamped on the left side of the case just above the oil
pan gasket surface (Fig. 2). The first set of numbers
is the transmission part number. The next set of code
numbers set is the date of build. The final set of code
numbers represents the transmission serial number.
SPECIFICATIONS AND BAND ADJUSTMENTS
Service specifications and torque values are located
at the end of this group. Refer to the specifications
during service operations.
The band adjustment specifications for 1994
transmissions are different. Refer to the front
and rear band adjustment procedures in the In-
Vehicle Service section for details.
PARTS INTERCHANGEABILITY
The 1994 version of the 30RH (A904) transmission
is similar to previous models in appearance only. The
current 30RH is quite different and interchanging
new/old parts is definitely not recommended. Differ-
ent component dimensions, fluid passages, input/out-
put shafts, cases, bands, valve bodies and governor
assemblies are just a few of the changed items. The
32RH transmission is also different from previous
models and the same recommendations apply here as
well.
CAUTION: On YJ models with a 2.5L engine and
30RH transmission, special bolts are used to attach
the driveplate to the crankshaft. These bolts have a
smaller hex head for torque converter clearance.
DO NOT interchange these bolts with similar size
bolts for any reason.
TRANSMISSION CONTROLS AND COMPONENTS
The transmission hydraulic control system per-
forms five basic functions, which are:
²pressure supply
²pressure regulation
²flow control
²clutch/band apply and release
²lubrication
Pressure Supply And Regulation
The oil pump generates the fluid working pressure
needed for operation and lubrication. The pump is
driven by the torque converter. The converter is con-
nected to the engine crankshaft through the drive-
plate.
The pressure regulator valve maintains operating
(line) pressure. The regulator valve is located in the
valve body. The amount of line pressure developed is
21 - 66 30RH/32RH AUTOMATIC TRANSMISSIONJ

Fig. 1 30RH/32RH Automatic Transmission
J30RH/32RH AUTOMATIC TRANSMISSION 21 - 67

controlled by throttle pressure, which is dependent
on the degree of throttle opening.
The governor valve is operated by the transmission
output shaft. Governor pressure increases in propor-
tion to vehicle speed.
The throttle valve determines line pressure and
shift speed. The throttle valve also controls upshift
and downshift speeds by regulating pressure in con-
junction with throttle position.
Shift Valves
The manual valve is operated by the gearshift link-
age and provides the operating range selected by the
driver.
The 1-2 shift valve provides automatic 1-2 or 2-1
shifts and the 2-3 shift valve provides automatic 2-3
or 3-2 shifts. The kickdown valve provides forced 3-2
or 3-1 downshifts depending on vehicle speed. Down-
shifts occur when the throttle is opened beyond
downshift detent position which is just before wide
open throttle.
The 2-3 valve throttle pressure plug provides 3-2
downshifts with varying throttle openings and de-
pending on vehicle speed. The 1-2 shift control valve
transmits 1-2 shift pressure to the accumulator pis-
ton to control kickdown band capacity on 1-2 upshifts
and 3-2 downshifts.The shuttle valve has two functions. First is fast
front band release and smooth engagement during
lift-foot 2-3 upshifts. The second is to regulate front
clutch and band application during 3-2 downshifts.
Clutches-Bands-Servos-Accumulator
The front/rear clutch pistons and servo pistons are
actuated by line pressure. When line pressure is re-
moved, the pistons are released by spring tension.
On 2-3 upshifts, the front servo piston is released
by spring tension and hydraulic pressure. The accu-
mulator controls hydraulic pressure on the apply side
of the front servo during 1-2 upshifts and at all
throttle openings.
Converter Clutch Controls
Converter clutch operation is controlled by the
power train control module, and by the solenoid and
clutch module on the valve body. The solenoid is op-
erated by a relay on the engine compartment side of
the dash panel.
Activating the solenoid opens a vent allowing fluid
to flow into the clutch module. When line pressure
exceeds tension of the module valve springs, the
module valves open. This allows fluid to be chan-
neled to the converter clutch through the reaction
shaft support and transmission shaft.
Gearshift And Parking Lock Controls
The gearshift lever provides six operating posi-
tions: Park (P), Reverse (R), Neutral (N), and the D,
2 and 1 forward drive ranges.
Manual 1 position provides first gear only. Overrun
braking occurs in 1 range when the throttle is re-
leased. Upshifts are not provided in 1 range.
Manual 2 range provides first and second gear. A
1-2 upshift will take place but a 2-3 upshift will not
occur.
D position provides 1-2, 2-3 upshifts and 3-2 and
3-1 downshifts.
Park position allows the park rod to move the park
pawl into engagement with the park gear. This pre-
vents rotation of the transmission output shaft. The
park lock mechanism is only engaged when the shift
lever is in the Park detent.
A park/neutral position switch controls engine
starting. The switch is designed to allow engine
starts only in park or neutral positions.
Fig. 2 Transmission Identification
21 - 68 30RH/32RH AUTOMATIC TRANSMISSIONJ

30RH/32RH TRANSMISSION DIAGNOSIS
INDEX
page page
Air Pressure Test........................ 73
Analyzing the Road Test................... 70
Converter Housing Leak Diagnosis........... 73
Converter Stall Test...................... 72
Diagnosis Guides and Charts............... 76
Fluid Level and Condition.................. 69Gearshift Linkage........................ 70
General Information....................... 69
Hydraulic Pressure Test................... 71
Preliminary Diagnosis..................... 69
Road Test.............................. 70
Transmission Throttle Valve Cable Adjustment . . 70
GENERAL INFORMATION
Automatic transmission problems are generally the
result of:
²poor engine performance
²incorrect fluid level
²incorrect cable/linkage adjustment
²incorrect band adjustment
²incorrect hydraulic control pressure adjustments
²hydraulic component malfunctions
²mechanical component malfunctions.
Begin diagnosis by checking the easily accessible
items such as fluid level, fluid condition and control
linkage adjustment. A road test will determine if fur-
ther diagnosis is necessary.
Procedures outlined in this section should be per-
formed in the following sequence to realize the most
accurate results:
²Preliminary diagnosis
²Check fluid Level and condition
²Check control linkage Adjustment
²Road test
²Stall test
²Hydraulic pressure test
²Air pressure tests
²Leak Tests
²Analyze test results and consult diagnosis charts
PRELIMINARY DIAGNOSIS
Two basic procedures are required. One procedure
for vehicles that are driveable and an alternate pro-
cedure for disabled vehicles (will not back up or
move forward).
Vehicle Is Driveable
(1) Check fluid level and condition.
(2) Adjust throttle cable and gearshift linkage if
complaint was based on delayed, erratic, or harsh
shifts.
(3) Road test vehicle and note transmission operat-
ing characteristics.
(4) Perform stall test if complaint is based on slug-
gish, low speed acceleration or abnormal throttle
opening needed to maintain normal speeds with
properly tuned engine.
(5) Perform hydraulic pressure tests.(6) Perform air pressure test to check clutch-band
operation.
Vehicle Is Disabled
(1) Check fluid level and condition.
(2) Check for broken, disconnected throttle link-
age.
(3) Check for cracked, leaking cooler lines, or
loose, missing pressure port plugs.
(4) Raise vehicle, start engine, shift transmission
into gear and note following:
(a) If propeller shafts turn but wheels do not,
problem is with differential or axle shafts.
(b) If propeller shafts do not turn and transmis-
sion is noisy, stop engine. Remove oil pan, and
check for debris. If pan is clear, remove transmis-
sion and check for damaged drive plate, converter,
oil pump or input shaft.
(c) If propeller shafts do not turn and transmis-
sion is not noisy, perform hydraulic pressure test to
determine if problem is a hydraulic or mechanical.
FLUID LEVEL AND CONDITION
(1) Position vehicle on level surface. This is impor-
tant 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) Clean dipstick filler cap and tube before remov-
ing dipstick.
(7) Remove dipstick and inspect fluid level.
²Correct level is to FULL mark
²Acceptable level is between ADD and FULL marks
J30RH/32RH TRANSMISSION DIAGNOSIS 21 - 69

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

AW-4 AUTOMATIC TRANSMISSION
CONTENTS
page page
AW-4 IN-VEHICLE SERVICE............. 173
AW-4 TRANSMISSION DIAGNOSIS........ 167
AW-4 TRANSMISSION OVERHAUL........ 192
AW-4 TRANSMISSION REMOVAL AND
INSTALLATION....................... 189GENERAL INFORMATION................ 156
TRANSMISSION/TRANSFER CASE
SPECIFICATIONS..................... 320
GENERAL INFORMATION
INDEX
page page
Components and Operation................ 157
Description............................ 156
FirstÐThirdÐReverse Gear Components...... 159
Fourth Gear Overdrive Components......... 158
Geartrain Operation and Application Charts.... 159Hydraulic System........................ 160
Torque Converter........................ 158
Transmission Identification................. 157
Transmission Ranges and Shift Lever Positions . 157
DESCRIPTION
The AW-4 is a 4-speed, electronically controlled au-
tomatic transmission (Fig. 1). Running gear consists
of a torque converter, oil pump, three planetary gear
sets, clutch and brake units, hydraulic accumulators,
a valve body with electrical solenoids and a transmis-sion control module (TCM). The AW-4 is used in XJ
models with a 4.0L engine.
Cables are used for shifting and transmission
throttle pressure control. A park/neutral position
switch permits engine starting in Park and Neutral
range only.
Fig. 1 AW-4 Automatic Transmission
21 - 156 TRANSMISSION AND TRANSFER CASEJ

The valve body solenoids are controlled by signals
from the transmission control module (TCM). Signal
sequence is determined by vehicle speed and throttle
position.
Fourth gear is an 0.75:1 ratio overdrive range.
First, second, third and reverse gear are conventional
ranges. Third gear ratio is 1:1. A separate planetary
gear set provides overdrive operation in fourth gear.
TRANSMISSION RANGES AND SHIFT LEVER
POSITIONS
The AW-4 transmission has six ranges and shift le-
ver positions. Park, Reverse and Neutral are conven-
tional and mechanically operated. The 1-2, 3 and D
ranges provide electronically controlled shifting.
The 1-2 position provides first and second gear
only. The 3 position provides first, second and third
gear.
The D range provides first through fourth gear.
Overdrive fourth gear range is available only when
the shift lever is in D position (Fig. 2).
TRANSMISSION IDENTIFICATION
The transmission I.D. plate is attached to the case
(Fig. 3). The plate contains the transmission serial
and model numbers. Refer to the information on this
plate when ordering service parts.
COMPONENTS AND OPERATION
ELECTRONIC CONTROLS
The AW-4 is electronically controlled in the 1, 2, 3
and D ranges. Controls consist of the transmission
control module (TCM), valve body solenoids and var-ious sensors. The sensors monitor vehicle speed,
throttle opening, shift lever position and brake pedal
application.
TRANSMISSION CONTROL MODULE (TCM)
The module determines shift and converter clutch
engagement timing based on signals from the sen-
sors. The valve body solenoids are activated, or deac-
tivated accordingly.
The module has a self diagnostic program. Compo-
nent and circuitry malfunctions can be diagnosed
with the DRB II scan tool. Once a malfunction is
noted and stored in control module memory, it is re-
tained even after the problem has been corrected. To
cancel a stored malfunction, simply disconnect and
reconnect the9Trans.9fuse in the module harness.
TRANSMISSION VALVE BODY SOLENOIDS
The solenoids are mounted on the valve body and
operated by the transmission control module. The so-
lenoids control operation of the converter clutch and
shift valves in response to input signals from the
module.
SENSORS
The sensors include the throttle position sensor
(TPS), transmission output speed sensor, vehicle
speed sensor, park/neutral position switch and brake
switch.
The throttle position sensor is mounted on the
throttle body. It electronically determines throttle po-
sition and relays this information to the transmission
control module to determine shift points and con-
verter clutch engagement.
The transmission speed sensor consists of a rotor
and magnet on the transmission output shaft and a
switch in the extension housing or adapter. The sen-
sor switch is activated each time the rotor and mag-
Fig. 2 AW-4 Shift Lever Positions And Transmission
Ranges
Fig. 3 Transmission Identification
JAW-4 AUTOMATIC TRANSMISSION 21 - 157

net complete one revolution. Sensor signals are sent
to the transmission control module.
The park/neutral position switch is mounted on the
valve body manual shaft. The switch signals shift
linkage and manual valve position to the transmis-
sion control module through an interconnecting har-
ness. The switch prevents engine starting in all gears
other than Park or Neutral.
The brake switch is in circuit with the torque con-
verter clutch solenoid. The switch disengages the
converter clutch whenever the brakes are applied.
The switch is mounted on the brake pedal bracket
and signals the transmission control module when
the pedal is pressed or released.
TORQUE CONVERTER
A four element torque converter is used for all ap-
plications. The converter consists of the front cover
and pump, stator, turbine, and an electronic modu-
lated converter clutch mechanism.
The converter clutch mechanism consists of a slid-
ing clutch piston, clutch springs and the clutch disc
material (Fig. 4). The clutch provides optimum
torque transfer and economy when engaged.
The clutch disc is attached to the converter front
cover. The clutch piston and clutch springs are at-
tached to the turbine hub. The springs dampen en-
gine firing impulses and loads during the initial
phase of converter clutch engagement.
Clutch engagement is controlled by transmission
valve body solenoid number three and by the con-
verter clutch relay valve. The solenoid channels line
pressure to the clutch through the relay valve at
clutch engagement speeds.
Torque converter clutch engagement occurs in sec-
ond gear in 1-2 position; third gear in 3 position and
third and fourth gear in D position.
FOURTH GEAR OVERDRIVE COMPONENTS
The overdrive system consists of the input shaft, one-
way clutch, planetary sun gear, ring gear, planetary car-
rier, direct clutch and overdrive brake (Fig. 5). The
overdrive elements are controlled and applied through
transmission valve body solenoid number two.
In overdrive fourth gear, the brake prevents the
overdrive sun gear from turning. During operation,
the overdrive elements operate as follows:
The overdrive input shaft and planetary carrier ro-
tate as a unit. The sun gear and overdrive direct
clutch drum are in mesh and operate as a single
unit. The direct clutch splines function as the hub for
the overdrive brake. The one-way clutch outer race is
in mesh with the planetary carrier. The inner race is
fixed to the sun gear shaft.
Fig. 5 Fourth Gear Overdrive Components
Fig. 4 Torque Converter With Modulated Clutch
21 - 158 AW-4 AUTOMATIC TRANSMISSIONJ