1994 JEEP CHEROKEE maint

tle body. Fuel is sprayed into the manifold by the fuel
injectors. The throttle body is mounted on the intake
manifold. It contains an air control passage (Fig. 26)
controlled by an Idle Air Control (IAC) motor. The air
control passage is used to supply air for idle condi-
tions. A throttle valve (plate) is used to supply air for
above idle conditions.
The throttle position sensor (TPS) and idle air con-
trol (IAC) motor are attached to the throttle body.
The accelerator pedal cable, speed control cable and
transmission control cable (when equipped) are con-
nected to the throttle arm.
A (factory adjusted) set screw is used to mechani-
cally limit the position of the throttle body throttle
plate.Never attempt to adjust the engine idle
speed using this screw.All idle speed functions are
controlled by the PCM.
FUEL RAIL
The fuel rail supplies fuel to the injectors and is
mounted to the intake manifold (Fig. 27). The fuelpressure regulator is attached to the rail and the fuel
pressure test port is integral with the rail. The fuel
rail is not repairable.
FUEL PRESSURE REGULATOR
The fuel pressure regulator (Fig. 28) is a mechani-
cal device that is not controlled by the powertrain
control module (PCM).
The fuel pressure regulator used is a vacuum bal-
anced, nonadjustable type. The regulator is mounted
on the output end of the fuel rail and is connected to
intake manifold vacuum. The fuel return tube (to the
fuel tank) is connected to the fuel pressure regulator.
The regulator is calibrated to maintain fuel system
pressure at approximately 214 kPa (31 psi). This is
with vacuum applied while the engine is at idle. Fuel
pressure will be 55-69 kPa (8-10 psi) higher if vac-
uum is not applied to the regulator.
The pressure regulator contains a diaphragm, cali-
brated spring and a fuel return valve (Fig. 29). Fuel
pressure operates on one side of the regulator, while
spring pressure and intake manifold vacuum operate
on the other side. Spring pressure on one side of the
Fig. 27 Fuel RailÐTypical
Fig. 28 Fuel Pressure RegulatorÐTypical
Fig. 25 Throttle BodyÐTypical
Fig. 26 Idle Air Control Passage
14 - 30 FUEL SYSTEMJ

DRB SCAN TOOL
For operation of the DRB scan tool, refer to the ap-
propriate Powertrain Diagnostic Procedures service
manual.
DIAGNOSTIC TROUBLE CODE (DTC)
On the following pages, a list of diagnostic trouble
codes is provided for the 2.5L 4 cylinder and 4.0L 6
cylinder engines. A DTC indicates that the power-
train control module (PCM) has recognized an abnor-
mal signal in a circuit or the system. A DTC may
indicate the result of a failure, but never identify the
failed component directly.
DIAGNOSTIC TROUBLE CODE DESCRIPTIONS
Diagnostic
Trouble
CodeDRB Scan Tool
DisplayDescription of Diagnostic Trouble Code
11* .......... NoCrank Reference
Signal at PCMNo crank reference signal detected during engine cranking.
12* ..........Battery Disconnect Direct battery input to PCM was disconnected within the last 50 Key-on
cycles.
13**.......... NoChange in MAP From
Start to RunNo difference recognized between the engine MAP reading and the
barometric (atmospheric) pressure reading at start-up.
14**.......... MAPSensor Voltage Too
LowMAP sensor input below minimum acceptable voltage.
or
MAP Sensor Voltage Too
HighMAP sensor input above maximum acceptable voltage.
15**.......... NoVehicle Speed Sensor
SignalNo vehicle distance (speed) sensor signal detected during road load
conditions.
17* ..........Engine is Cold Too Long Engine coolant temperature remains below normal operating temperatures
during vehicle travel (thermostat).
21**.......... O2SStays at Center Neither rich or lean condition detected from the oxygen sensor input.
or
O2S Shorted to Voltage Oxygen sensor input voltage maintained above the normal operating range.
22**.......... ECTSensor Voltage Too
HighEngine coolant temperature sensor input above maximum acceptable
voltage.
or
ECT Sensor Voltage Too
LowEngine coolant temperature sensor input below minimum acceptable voltage.
* Check Engine Lamp will not illuminate at all times if this Diagnostic Trouble Code was recorded. Cycle Ignition key as
described in manual and observe code flashed by Check Engine lamp.
** Check Engine Lamp will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
Fig. 47 Data Link Connector Schematic
JFUEL SYSTEM 14 - 51

(4) Remove bearing spacer, races and thrust bear-
ing (Fig. 21).
(5) Remove O-ring seal.
(6) Remove retaining snap ring.
(7) Remove needle bearing, dust seal and lip seal
with an appropriate tool (Fig. 22).
ASSEMBLE
CAUTION: Needle bearing must be installed with
identification on bearing facing tool to prevent dam-
age to bearing.(1) Install needle bearing into adjuster plug with
an appropriate tool.
(2) Install lip seal and dust seal into adjuster plug
with an appropriate tool.
(3) Install retainer snap ring.
(4) Install O-ring seal to adjuster plug.
(5) Install large bearing race, thrust bearing, small
bearing race and bearing spacer to adjuster plug.
(6) Install thrust washer bearing retainer to ad-
juster plug (Fig. 23).
CAUTION: When installing adjuster plug, care
should be taken NOT to cut the seals.
(7) Install adjuster plug into housing with Spanner
Wrench C-4381 (J7624).
(8) Adjust bearing preload, refer to Thrust Bearing
Preload Adjustment.
(9) Install adjuster plug lock nut, and using a
punch (drift) in a notch, tighten securely (Fig. 24).
Hold adjuster plug to maintain alignment of the
marks.
(10) Adjust pitman shaft. Refer to Over-Center Ad-
justment.
INSTALL
(1) Install steering gear. Refer to Power Steering
Gear Replacement in this section.
VALVE REPLACEMENT
REMOVE
(1) Remove steering gear from vehicle. Refer to
Power Steering Gear Replacement in this section.
DISASSEMBLE
(1) Remove adjuster plug, refer to Adjuster Plug
Assembly Replacement.
Fig. 21 Adjustment Plug (Cap) Components
Fig. 22 Needle Bearing Removal
Fig. 23 Install Retainer
19 - 28 STEERINGJ

CLEAN AND INSPECTION
(1) Wash all components in clean solvent and dry
with compressed air.
(2) Check for scores, nicks or burrs on the rack pis-
ton finished surface. Slight wear is normal on the
worm gear surfaces.
ASSEMBLE
(1) Install O-ring seal and teflon ring and lubricate
with power steering fluid.
(2) Install worm shaft to rack piston outside of
housing. Fully seat worm shaft to rack piston and
align worm shaft spiral groove with rack piston ball
guide hole (Fig. 33).
WARNING: MAKE SURE ALL RACK PISTON BALLS
ARE REINSTALLED IN THE RACK PISTON. IM-
PROPER INSTALLATION MAY RESULT IN PER-
SONAL INJURY.There are 24 balls in the rack piston circuit,
12 are black and 12 are silver (Chrome). The
black rack piston balls are smaller than the sil-
ver balls. THE BLACK AND SILVER BALLS
MUST BE INSTALLED ALTERNATELY INTO
THE RACK PISTON AND BALL GUIDE. This
procedure will maintain worm shaft preload.
(3) Lubricate and install rack piston balls through
return guide hole while turning wormshaft COUN-
TERCLOCKWISE.
(4) Install remaining balls to guide using grease or
petroleum jelly at each end to hold in place (Fig. 34).
(5) Install guide onto rack piston and return with
clamp and screws. Tighten screws to 58 Nzm (43 in.
lbs.) torque.
(6) Insert Arbor C-4175 (J-21552) into bore of rack
piston. Hold tool tightly against worm shaft while
Fig. 34 Balls in the Return Guide
Fig. 31 Remove and Install Rack Piston
Fig. 32 Remove and Install Seal on Rack Piston
Fig. 33 Installing Balls in Rack Piston
JSTEERING 19 - 31

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

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

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

rect sequence. The correct sequence is line pressure
adjustment first and throttle pressure adjustment
last.
Line Pressure Adjustment
Measure distance from the valve body to the inner
edge of the adjusting screw with an accurate steel
scale (Fig. 119).
Distance should be 33.4 mm (1-5/16 in.).
If adjustment is required, turn the adjusting screw
in, or out, to obtain required distance setting.
The 33.4 mm (1-5/16 in.) setting is an approxi-
mate setting. Because of manufacturing toler-
ances, it may be necessary to vary from this
dimension to obtain desired pressure.
One complete turn of the adjusting screw changes
line pressure approximately 1-2/3 psi (9 kPa). Turn-
ing the adjusting screw counterclockwise increases
pressure while turning the screw clockwise decreases
pressure.
Throttle Pressure Adjustment
Insert Gauge Tool C-3763 between the throttle le-
ver cam and the kickdown valve stem (Fig. 120).
Push the gauge tool inward to compress the kick-
down valve against the spring and bottom the throt-
tle valve.
Maintain pressure against kickdown valve spring.
Turn throttle lever stop screw until the screw head
touches throttle lever tang and the throttle lever cam
touches gauge tool.
The kickdown valve spring must be fully com-
pressed and the kickdown valve completely
bottomed to obtain correct adjustment.
TRANSMISSION ASSEMBLY TIPS
Do not allow dirt, grease, or foreign material to en-
ter the case or transmission components during as-
sembly. Keep the transmission case and components
clean. Also make sure the tools and workbench area
used for assembly are equally clean.Shop towels used for wiping off your hands and ser-
vice tools must be made oflint freematerials. Lint
will adhere to transmission parts and could interfere
with valve operation, or even restrict fluid passages.
Lubricate the transmission components with ATF
Plus, or Dexron IIŸ during reassembly. Use petro-
leum jelly, Door Eze, or Ru-Glyde on seals and
O-rings to ease installation.
Petroleum jelly can also be used to hold thrust
washers and plates in position during assembly oper-
ations. However,do notuse chassis grease, bearing
grease, white grease, or similar lubricants on any
transmission part. These types of lubricants can
eventually block or restrict fluid passages and valve
operation. Use petroleum jelly only.
Do not force parts into place. Most of the transmis-
sion components are easily installed by hand when
properly aligned. If a part seems extremely difficult
to install, it is either misaligned or incorrectly as-
sembled. Also verify that thrust washers, thrust
plates and seal rings are correctly positioned before
assembly. These parts can interfere with proper as-
sembly if mispositioned or ``left out'' by accident.
TRANSMISSION ASSEMBLY AND ADJUSTMENT
PROCEDURES
SERVO INSTALLATION
(1) Install rear servo piston, spring and spring re-
tainer. Compress rear servo spring and retainer with
Compressor Tool C-3422-B or a large C-clamp.
(2) Install front servo piston, spring and rod guide.
Compress front servo rod guide with Valve Spring
Compressor C-3422-B and install servo snap ring.
OVERRUNNING CLUTCH INSTALLATION
(1) Examine bolt holes in overrunning clutch cam.
Note that one hole isnot threaded(Fig. 121). This
hole must align with blank area in clutch cam bolt
circle (Fig. 122).
Fig. 120 Throttle Pressure Adjustment
Fig. 119 Line Pressure Adjustment
21 - 146 30RH/32RH TRANSMISSION OVERHAULJ