YJ BUMPERS AND FRAME ATTACHED COMPONENTS
INDEX
page page
Generator Splash Shield................... 14
Body.................................. 18
Engine Front Support Cushion............... 15
Frame Crossmember Cover................. 14
Front Bumper........................... 14
Fuel and Brake Fluid Tube Retainer Clip....... 16
Fuel Filter Shield and Bracket............... 17
Fuel Tank Skid Plate...................... 16Muffler and Tailpipe Heat Shields............ 17
Muffler/Tailpipe Hanger Bracket.............. 16
Rear Bumper............................ 18
Rear Jounce Bumper..................... 18
Service Information....................... 14
Tow Hooks............................. 14
Transfer Case Skid Plate.................. 15
SERVICE INFORMATION
In some cases, components in the following proce-
dures either support, or are hidden by other compo-
nents.
FRONT BUMPER
The YJ front bumper is a one-piece rail (Fig. 1). A
front crossmember cover (Fig. 1) is also installed on
all YJ vehicles.
BUMPER REMOVAL
(1) Disconnect and remove the fog lamps, if
equipped.
(2) Remove the nuts and bolts that retain the
bumper extensions to the bumper rail and remove
the extensions.
(3) Remove the nuts and bolts that attach the
bumper rail/tow hooks to the frame rails.(4) Remove the bumper rail from the frame rails.
BUMPER INSTALLATION
(1) Position the front bumper on the frame rails.
(2) Install the bolts and attach the front bumper
rail (and tow hooks, if equipped) to the frame rails.
(3) Tighten the bolts to 102 Nzm (75 ft-lbs) torque.
(4) Position the bumper extensions on the bumper
rail and install the retaining bolts.
(5) Tighten the bolts to 104 Nzm (77 ft-lbs) torque.
(6) Install the fog lamps, if equipped.
FRAME CROSSMEMBER COVER
REMOVAL
(1) Remove the screws that attach the crossmem-
ber cover and support to the frame rails.
(2) Remove the crossmember cover and support
from the frame rails.
INSTALLATION
(1) Position the support and crossmember cover on
the frame rails.
(2) Install the attaching screws.
(3) Tighten the screws to 8 Nzm (72 in-lbs) torque.
TOW HOOKS
REMOVAL
(1) Remove the two bolts that attach the tow hook
to the bumper rail and to the frame rail.
(2) Remove the tow hook.
INSTALLATION
(1) Position the tow hook on the bumper rail and
frame rail.
(2) Install the attaching bolts.
(3) Tighten the bolts to 102 Nzm (75 ft-lbs) torque.
GENERATOR SPLASH SHIELD
REMOVAL
(1) Remove the shield retaining nut and washer
(Fig. 2) from the engine oil pan stud (2.5L engines
only).
Fig. 1 Front Bumper Rail, Crossmember Cover &
Tow Hooks
13 - 14 FRAME AND BUMPERSJ
charges when the PCM supplies a ground. By switch-
ing the ground path on and off, the PCM regulates
ignition timing.
The sensors and switches that provide inputs to the
powertrain control module (PCM) comprise the En-
gine Control System. It is also comprised of the PCM
Outputs (engine control devices that the are operated
by the PCM).
SYSTEM DIAGNOSIS
The powertrain control module (PCM) tests many
of its own input and output circuits. If a Diagnostic
Trouble Code (DTC) is found in a major system, this
information is stored in the PCM memory. Refer to
On-Board Diagnostics in the MFI SystemÐGeneral
Diagnosis section of this group for DTC information.
POWERTRAIN CONTROL MODULE (PCM)
The PCM operates the fuel system. The PCM was
formerly referred to as the SBEC or engine control-
ler. The PCM is a pre-programmed, dual micropro-
cessor digital computer. It regulates ignition timing,
air-fuel ratio, emission control devices, charging sys-
tem, speed control, air conditioning compressor
clutch engagement and idle speed. The PCM can
adapt its programming to meet changing operating
conditions.
On XJ models, the PCM is located in the engine
compartment next to the air cleaner (Fig. 1). On YJ
models, the PCM is located in the engine compart-
ment behind the windshield washer fluid reservoir
(Fig. 2).
The PCM receives input signals from various
switches and sensors. Based on these inputs, the
PCM regulates various engine and vehicle operations
through different system components. These compo-
nents are referred to as PCM Outputs. The sensors
and switches that provide inputs to the PCM are con-
sidered PCM Inputs.The PCM adjusts ignition timing based upon in-
puts it receives from sensors that react to: engine
rpm, manifold absolute pressure, coolant tempera-
ture, throttle position, transmission gear selection
(automatic transmission), vehicle speed and the
brake switch.
The PCM adjusts idle speed based on inputs it re-
ceives from sensors that react to: throttle position,
vehicle speed, transmission gear selection, coolant
temperature and from inputs it receives from the air
conditioning clutch switch and brake switch.
Based on inputs that it receives, the PCM adjusts
ignition coil dwell. The PCM also adjusts the gener-
ator charge rate through control of the generator
field and provides speed control operation.
Powertrain Control Module (PCM) Inputs:
²Generator output
²A/C request (if equipped with factory A/C)
²A/C select (if equipped with factory A/C)
²Auto shut down (ASD) sense
²Intake air temperature sensor
²Battery voltage
²Brake switch
²Engine coolant temperature sensor
²Crankshaft position sensor
²Ignition circuit sense (ignition switch in run posi-
tion)
²Manifold absolute pressure sensor
²Overdrive/override switch
²Oxygen sensor
²Park/neutral switch (auto. trans. only)
²SCI receive (DRB scan tool connection)
²Speed control resume switch
²Speed control set switch
²Speed control on/off switch
²Camshaft position sensor signal
²Throttle position sensor
²Vehicle speed sensor
²Sensor return
²Power ground
Fig. 1 PCM LocationÐXJ Models
Fig. 2 PCM LocationÐYJ Models
14 - 18 FUEL SYSTEMJ
(3) Lower the vehicle.
PARK NEUTRAL SWITCH
Refer to Group 21, Transmissions for park neutral
switch service.
POWER STEERING PRESSURE SWITCHÐ2.5L
ENGINE ONLY
The power steering pressure switch is installed in
the power steering high pressure hose (Figs. 11 or
12).
REMOVAL
(1) Disconnect the electrical connector from the
power steering pressure switch.
(2) Place a small container or shop towel beneath
the switch to collect any excess fluid.
(3) Remove the switch.
INSTALLATION
(1) Install the power steering switch.
(2) Connect the electrical connector to the switch.(3) Check power steering fluid and add as neces-
sary.
(4) Start the engine and again check power steer-
ing fluid. Add fluid if necessary.
POWERTRAIN CONTROL MODULE (PCM)
On XJ models, the PCM is located in the engine
compartment next to the air cleaner (Fig. 13). On YJ
models, the PCM is located in the engine compart-
ment behind the windshield washer fluid reservoir
(Fig. 14).
REMOVAL
(1) Disconnect the negative battery cable at the
battery.
(2) YJ Models Only: Remove the windshield
washer fluid tank.
(3) Loosen the 60-Way connector mounting bolt
(Figs. 13 or 14).
(4) Remove the electrical connector by pulling
straight back.
(5) Remove the three PCM mounting bolts.
(6) Remove PCM.
Fig. 11 Power Steering Pressure SwitchÐYJ Models
Fig. 12 Power Steering Pressure SwitchÐXJ Models
Fig. 13 PCM LocationÐXJ Models
Fig. 14 PCM LocationÐYJ Models
14 - 58 FUEL SYSTEMJ
INSTALLATION
(1) After the PCM electrical connector has been
separated from the PCM, inspect the pins for corro-
sion, being spread apart, bent or misaligned. Also in-
spect the pin heights in the connector. If the pin
heights are different, this would indicate a pin has
separated from the connector. Repair as necessary.
(2) Install PCM. Tighten three mounting bolts to 1
Nzm (9 in. lbs.) torque.
(3) Engage 60-way connector into PCM. Tighten
connector mounting bolt to 4 Nzm (35 in. lbs.) torque.
(4) YJ Models: Install windshield washer fluid
tank.
(5) Connect negative cable to battery.
QUICK-CONNECT FITTINGS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures.
THROTTLE BODY
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect air cleaner hose from throttle body.
(3) Disconnect idle air control motor and throttle
position sensor wire connectors.
(4) Disconnect accelerator cable, throttle cable (au-
tomatic transmission) and speed control cable (if
equipped) from throttle arm (Fig. 15).
(5) Remove throttle body mounting bolts, throttle
body and gasket. Discard old gasket (Fig. 16).
INSTALLATION
(1) Install throttle body and new gasket. Tighten
throttle body mounting bolts to 12 Nzm (9 ft. lbs.)
torque.
(2) Connect idle air control motor and throttle po-
sition sensor wire connectors.
(3) Connect throttle linkage to throttle arm.CAUTION: When the automatic transmission throttle
cable is connected, it MUST be adjusted.
(4) If equipped with an automatic transmission,
connect and adjust the transmission line pressure ca-
ble. Refer to Group 21, Transmissions for adjustment
procedure.
(5) Install air cleaner hose to throttle body.
(6) Connect negative battery cable to battery.
THROTTLE POSITION SENSOR (TPS)
The TPS is mounted to the throttle body (Figs. 17
or 18).
REMOVAL
(1) Disconnect TPS electrical connector.
(2) Remove TPS mounting bolts.
(3) Remove TPS.
INSTALLATION
The throttle shaft end of the throttle body slides
into a socket in the TPS (Fig. 19). The TPS must be
installed so that it can be rotated a few degrees. (If
Fig. 16 Throttle
BodyÐRemoval/InstallationÐTypical
Fig. 17 TPS LocationÐ2.5L Engine
Fig. 15 Cables at Throttle Body
JFUEL SYSTEM 14 - 59
PITMAN SHAFT SEALSÐIN CAR REPLACEMENT
REMOVAL
(1) Remove pitman arm from gear. Refer to Pit-
man Arm Removal in Steering Linkage.
(2) Clean exposed end of pitman shaft and housing.
Use a wire brush to clean the shaft splines.
(3) Remove retaining ring with snap ring pliers
(Fig. 2).
CAUTION: Use care not to score the housing bore
when prying out seals and washers.
(4) Remove backup washer and double lip seal
with screwdriver.
²Start the engine and turn the steering wheel fully
to the LEFT to force out the seals and washers.
²Stop the engine
(5) Remove backup washer and single lip seal with
screwdriver.
(6) Inspect the housing for burrs and remove if
necessary. Inspect the pitman shaft seal surface for
roughness and pitting. If pitted replace shaft.
INSTALLATION
(1) Install single lip seal with Installer or a suit-
able size deep socket (Fig. 3).
(2) Coat the double lip seal and washer with
grease.
(3) Install the backup washer.
(4) Install the double lip seal.
(5) Install the backup washer.
(6) Install the retainer ring with snap ring pliers.
(7) Center the steering gear.
(8) Install the pitman arm. Refer to Pitman Arm
Installation in Steering Linkage.(9) Add power steering fluid. Refer to Power Steer-
ing Initial Operation.
INTERMEDIATE (COUPLING) SHAFT
REMOVAL
(1) Place the front wheels in the straight ahead po-
sition.
(2) Remove the shaft pinch bolt at the steering
gear and column (Fig. 4, 5). Unbolt steering gear
from frame rail to remove shaft. Refer to Steering
Gear Replacement in this section.
INSTALLATION
(1) Align the intermediate (coupler) shaft to the
steering gear and column.
(2) Position the steering gear on the frame. Refer
to Steering Gear Replacement in this section.
(3) Install and tighten the pinch bolts to 34 Nzm
(25 ft. lbs.) torque.
STEERING GEAR REPLACEMENT
REMOVAL
(1) Place the front wheels in the straight ahead po-
sition with the steering wheel centered.
(2) Disconnect and cap the fluid hoses from steer-
ing gear. Refer to Pressure and Return Hose Replace-
ment in this Group.
(3) Remove the column coupler shaft from the gear.
Refer to the removal procedures in this section.
(4) Remove pitman arm from gear. Refer to Pitman
Arm Removal in the Steering Linkage section.
Fig. 2 Pitman Shaft Seals
Fig. 3 Pitman Shaft Seal Installation
JSTEERING 19 - 21
CAUTION: Do not turn stub shaft any farther than
necessary. The recirculating balls will drop out of
the rack piston circuit and fall inside the rack pis-
ton chamber.
(3) Remove O-ring seal (Fig. 17).
ASSEMBLE
²Lubricate O-ring seal with power steering fluid
(1) Install O-ring into housing.
(2) Install plug, tap lightly with a plastic mallet to
seat it.
(3) Install retaining ring with open end 25 mm (1
inch) from access hole (Fig. 18).
INSTALL
(1) Install steering gear. Refer to Power Steering
Gear Replacement in this section.(2) Install pitman arm onto steering gear. Refer to
Steering Linkage in this Group.
ADJUSTER PLUG ASSEMBLY REPLACEMENT
REMOVE
(1) Remove steering gear from vehicle. Refer to
Power Steering Gear Replacement in this section.
DISASSEMBLE
(1) Remove adjuster plug lock nut from housing.
(2) Remove adjuster plug from housing with Span-
ner Wrench C-4381 (J7624) (Fig. 19).
(3) Remove thrust washer bearing retainer from
adjuster plug with screwdriver (Fig. 20).
Fig. 17 End Plug Components
Fig. 18 Installing The Retaining Ring
Fig. 19 Remove/Install Adjustment Plug
Fig. 20 Remove Retainer
JSTEERING 19 - 27
OIL FILTER REPLACEMENT
(1) Raise vehicle.
(2) Remove oil pan and drain fluid.
(3) Remove filter screws and remove oil filter (Fig.
9).
(4) Position new filter on valve body and install fil-
ter screws finger tight.
(5) Tighten filter screws to 4 Nzm (35 in. lbs.) with
inch pound torque wrench.
(6) Position new gasket on oil pan and install pan
on transmission. Tighten pan bolts to 17 Nzm (150 in.
lbs.) torque.
(7) Lower vehicle.
(8) Refill transmission with Mopar ATF Plus, Type
7176. Mopar Dexron II can be used if ATF Plus is not
readily available.
VALVE BODY REMOVAL
(1) Raise vehicle.
(2) Remove oil pan and drain fluid.
(3) Disconnect gearshift and throttle linkage at
transmission levers.
(4) Loosen clamp bolts and remove throttle and
manual valve levers from manual valve shaft.
(5) Disconnect park/neutral position switch wires
and remove switch and switch seal.
(6) Remove valve body oil filter.(7) Remove valve body attaching screws. Lower
valve body slightly and remove accumulator piston
and spring (Fig. 10). Rotate valve body down and
away from case. Pull it forward to disengage park
rod and remove valve body.
(8) Position valve body on bench or on repair stand
for disassembly, cleaning and inspection (Fig. 11).
VALVE BODY SERVICE
The valve body can be disassembled for cleaning
and inspection of the individual components. Valve
body service procedures are detailed in the overhaul
section.
The only serviceable valve body components are:
²park lock rod and E-clip
²switch valve and spring
²pressure adjusting screw bracket
²throttle valve lever
²manual lever
²manual lever shaft seal, washer, E-clip and detent
ball
²fluid filter
²converter clutch solenoid
The remaining valve body components are serviced
only as part of a complete valve body assembly.
Fig. 9 Oil Filter Screw Locations
Fig. 10 Accumulator Piston And Spring
Fig. 8 Rear Band Lever And Adjusting Screw
Location
21 - 100 30RH/32RH IN-VEHICLE SERVICEJ
GOVERNOR DISASSEMBLY
(1) Remove governor weights and spring from body
(Fig. 13).
(2) Remove snap ring and separate inner weight
and outer weight and spring (Fig 13).
(3) Remove bolts attaching governor to park gear
(Fig. 13).
(4) Remove park gear from governor body.
(5) Remove filter screen from park gear or gover-
nor body (Fig. 13).
CLEANING AND INSPECTION
Thoroughly clean all the governor parts in a suit-
able cleaning solution but do not use any type of
caustic cleaning agents.
The weights and valves should fall freely in their
bores when clean and dry. Minor surface scratches
and burrs can be removed with crocus cloth.
Inspect the governor weight spring for distortion.
Replace the spring, if damaged. Clean the filter in
solvent and dry it with compressed air. Replace the
filter, if damaged. Inspect the park gear for chipped
or worn gear teeth or damaged ring grooves. Replace
the gear, if damaged.
GOVERNOR ASSEMBLY
The governor valve used in 30RH/31RH/32RH
transmissions built since the 1992 model year, is
made of aluminum. In addition, the output shaft
has been spotfaced to accept the new aluminum
valve. The aluminum valve must not be used in
previous transmissions. The valve can only be
used with an output shaft that has been spot-
faced for valve end clearance. In addition, thegovernor body and output shaft must be prop-
erly indexed during reassembly. Be sure to in-
dex these components as described in the
Transmission Assembly and Adjustment proce-
dures.
(1) Install filter screen in park gear.
(2) Assemble governor body and park gear. Be sure
oil passages in body and gear are aligned.
(3) Install governor-to-park gear bolts finger tight
only at this time.
(4) Install governor weight snap ring in governor
body. Then install governor weight and spring assem-
bly in governor body.
GOVERNOR INSTALLATION
(1) Align and install park gear/governor assembly
on output shaft.
(2) Align valve shaft bore in governor body with
bore in output shaft.Be sure hole in output shaft
for governor valve shaft is aligned with gover-
nor valve bore in governor body. Valve shaft
will bind if misalignment occurs. Remove and
reposition governor body if necessary.
(3) Install governor valve and shaft. Be sure shaft
slides freely in bore before installing E-clip on shaft.
(4) Install governor valve on shaft and in governor
body. Then install remaining shaft retaining snap
ring.
(5) Install components that retain governor body
and park gear on output shaft as follows:
(a) On models with single snap ring, install snap
ring (Fig. 12). Be sure ring is seated in shaft.
(b) On models with thrust washer and two snap
rings, install thin snap ring first. Then install
thrust washer second and thick snap ring last (Fig.
12).
16(c) Verify correct position of snap rings.Be
sure flat side of each snap ring is toward gov-
ernor body.
(6) Tighten governor-to-park gear bolts to 11 Nzm
(95 in. lbs.).
(7) Install adapter and gasket on transmission.
Tighten adapter bolts to 32 Nzm (24 ft. lbs.).
(8) Install transfer case and rear crossmember.
(9) Connect speedometer cable, or vehicle speed
sensor wires exhaust pipe brackets and brake cable,
if removed.
(10) Align and connect propeller shafts. Tighten
clamp bolts to 19 Nzm (14 ft. lbs.) torque.
(11) Remove supports and lower vehicle.
(12) Check and adjust transmission fluid level.
PARK LOCK COMPONENT REPLACEMENT
COMPONENT REMOVAL
(1) Raise vehicle and remove transfer case and
adapter housing from transmission.
Fig. 13 Governor Components
21 - 102 30RH/32RH IN-VEHICLE SERVICEJ