THROTTLE BODY
DESCRIPTION
The throttle body is located on the intake manifold.
Fuel does not enter the intake manifold through the
throttle body. Fuel is sprayed into the manifold by
the fuel injectors.
OPERATION
Filtered air from the air cleaner enters the intake
manifold through the throttle body. The throttle body
contains an air control passage controlled by an Idle
Air Control (IAC) motor. The air control passage is
used to supply air for idle conditions. A throttle valve
(plate) is used to supply air for above idle conditions.
Certain sensors 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 body linkage 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.
REMOVAL
REMOVAL - 4.0L
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 Powertrain Control Module (PCM).
(1) Remove air cleaner duct and air resonator box
at throttle body.
(2) Disconnect throttle body electrical connectors
at MAP sensor, IAC motor and TPS (Fig. 35).
Fig. 33 Oxygen Sensor LocationsÐ4.0L Engine
14 - 52 FUEL INJECTIONWJ
O2S SENSOR (Continued)
STEERING
TABLE OF CONTENTS
page page
STEERING
DESCRIPTION - POWER STEERING SYSTEM . . 1
OPERATION - POWER STEERING SYSTEM . . . 1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER
STEERING SYSTEM....................2
DIAGNOSIS AND TESTING - STEERING
FLOW AND PRESSURE.................4DIAGNOSIS AND TESTING - 4.7L -
HYDRAULIC..........................5
COLUMN...............................7
GEAR.................................16
LINKAGE..............................26
PUMP.................................31
STEERING
DESCRIPTION - POWER STEERING SYSTEM
The power steering pump (Fig. 1) is a constant
flow rate and displacement vane type pump. The
pump reservoir is attached to the pump body. The
pump is connected to the steering by the pressure
and return hoses. The steering gear (Fig. 1) used is a
recirculating ball type gear. A tilt and non-tilt column
provide steering input.
The power steering system consists of:
OPERATION - POWER STEERING SYSTEM
The rack piston balls act as a rolling thread
between the worm shaft and rack piston. The worm
shaft is supported by a thrust bearing at the lower
end and a bearing assembly at the upper end. When
the worm shaft is turned from input from the steer-
ing column the rack piston moves. The rack piston
teeth mesh with the pitman shaft. Turning the worm
shaft turns the pitman shaft, which moves the steer-
ing linkage.
Fig. 1 POWER STEERING GEAR & PUMP 4.0L
1 - STEERING GEAR
2 - PRESSURE HOSE
3 - PUMP
4 - RETURN HOSE
5 - RESERVOIR
WJSTEERING 19 - 1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER STEERING SYSTEM
STEERING NOISE
There is some noise in all power steering systems. One of the most common is a hissing sound evident at a
standstill parking. Or when the steering wheel is at the end of it's travel. Hiss is a high frequency noise similar
to that of a water tap being closed slowly. The noise is present in all valves that have a high velocity fluid passing
through an orifice. There is no relationship between this noise and steering performance.
CONDITION POSSIBLE CAUSES CORRECTION
OBJECTIONAL HISS OR
WHISTLE1. Steering intermediate shaft to dash panel
seal.1. Check and repair seal at dash
panel.
2. Noisy valve in power steering gear. 2. Replace steering gear.
RATTLE OR CLUNK 1. Gear mounting bolts loose. 1. Tighten bolts to specification.
2. Loose or damaged suspension
components/track bar.2. Inspect and repair suspension.
3. Loose or damaged steering linkage. 3. Inspect and repair steering
linkage.
4. Internal gear noise. 4. Replace gear.
5. Pressure hose in contact with other
components.5. Reposition hose.
CHIRP OR SQUEAL 1. Loose belt. 1. Adjust or replace.
2. Belt routing. 2. Verify belt routing is correct.
WHINE OR GROWL 1. Low fluid level. 1. Fill to proper level.
2. Pressure hose in contact with other
components.2. Reposition hose.
3. Internal pump noise. 3. Replace pump.
4. Air in the system. 4. Perform pump initial operation.
SUCKING AIR SOUND 1. Loose return line clamp. 1. Replace clamp.
2. O-ring missing or damaged on hose
fitting.2. Replace o-ring.
3. Low fluid level. 3. Fill to proper level.
4. Air leak between pump and reservoir. 4. Repair as necessary.
SCRUBBING OR
KNOCKING1. Wrong tire size. 1. Verify tire size.
2. Wrong gear. 2. Verify gear.
19 - 2 STEERINGWJ
STEERING (Continued)
GEAR
TABLE OF CONTENTS
page page
GEAR
DESCRIPTION.........................16
OPERATION...........................16
REMOVAL.............................16
INSTALLATION.........................16
ADJUSTMENTS
STEERING GEAR.....................18
SPECIFICATIONS
POWER STEERING GEAR..............18
SPECIAL TOOLS
POWER STEERING GEAR..............19
PITMAN SHAFT
REMOVAL.............................20INSTALLATION.........................20
PITMAN SHAFT BEARING
REMOVAL.............................22
INSTALLATION.........................22
PITMAN SHAFT SEAL
REMOVAL.............................22
INSTALLATION.........................23
RACK PISTON/VALVE ASSEMBLY
REMOVAL.............................23
INSTALLATION.........................25
STUB SHAFT HOUSING
REMOVAL.............................25
INSTALLATION.........................25
GEAR
DESCRIPTION
The power steering gear is a recirculating ball type
gear (Fig. 1) .
The following gear components can be serviced:
²Pitman Shaft and Cover
²Pitman Shaft Bearings
²Pitman Shaft Oil Seal/Dust Seal
²Stud Shaft Housing with Seal
²O-Rings and Teflon Rings
NOTE: If rack piston assembly is damaged the gear
must be replaced.
OPERATION
The gear acts as a rolling thread between the
worm shaft and rack piston. The worm shaft is sup-
ported by a thrust bearing at the lower end and a
bearing assembly at the upper end. When the worm
shaft is turned the rack piston moves. The rack pis-
ton teeth mesh with the pitman shaft. Turning the
worm shaft turns the pitman shaft, which turns the
steering linkage.
REMOVAL
(1) Place the front wheels in the straight ahead
position with the steering wheel centered and locked.
(2) Remove the air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
(3) Drain or siphon the power steering system.(4) Remove the pressure and return lines (Fig.
2)from the steering gear. Refer to hose removal in
this section.
(5) Remove the column coupler shaft bolt (Fig.
2)and remove the shaft from the gear.
(6) Raise and support the vehicle.
(7) Remove the left front wheel and tire assembly.
(8) Remove the pitman arm from gear with Puller
C-4150A.
(9) Remove the windshield washer reservoir,(Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WASHER
RESERVOIR - REMOVAL).
(10) Remove the steering gear mounting bolts.
Remove the steering gear out of the engine compart-
ment (Fig. 3).
INSTALLATION
(1) Position the steering gear on the frame rail and
install the bolts. Tighten the bolts to 108 N´m (80 ft.
lbs.) torque.
(2) Install the pitman arm and tighten nut to 251
N´m (185 ft. lbs.).
(3) Install windshield washer reservoir,(Refer to 8 -
ELECTRICAL/WIPERS/WASHERS/WASHER RES-
ERVOIR - INSTALLATION).
(4) Install the wheel and tire assembly.
(5) Remove the support and lower the vehicle.
(6) Install the pressure and return hoses to the
steering gear and tighten to 20-38 N´m (14-28 ft.
lbs.).
(7) Install the column coupler shaft.
(8) Install the air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
19 - 16 GEARWJ
LINKAGE
TABLE OF CONTENTS
page page
LINKAGE
DESCRIPTION
STEERING LINKAGE ± RIGHT HAND DRIVE
(RHD) VEHICLES......................26
DESCRIPTION........................26
SPECIFICATIONS
TORQUE CHART......................28
SPECIAL TOOLS
STEERING LINKAGE...................28
DAMPER
DESCRIPTION.........................28
OPERATION...........................28
REMOVAL.............................28
INSTALLATION.........................29
DRAG LINK
DESCRIPTION.........................29OPERATION...........................29
REMOVAL.............................29
INSTALLATION.........................29
PITMAN ARM
DESCRIPTION.........................29
OPERATION...........................29
REMOVAL.............................29
INSTALLATION.........................30
TIE ROD END
DESCRIPTION.........................30
OPERATION...........................30
REMOVAL.............................30
INSTALLATION.........................30
LINKAGE
DESCRIPTION
STEERING LINKAGE ± RIGHT HAND DRIVE
(RHD) VEHICLES
Vehicles equipped with right hand drive (RHD)
steering utilize the same components of left hand
drive vehicles. The RHD Steering linkage is designed
as a mirror image of left hand drive linkage with the
exception of the steering damper (Fig. 1), which is
mounted on the same side of the vehicle weather
RHD or LHD. See figure below for reference. All
specifications are the same as LHD. Refer to Group
19, Steering of the gasoline engine service manual for
additional information.
DESCRIPTION
The steering linkage consists of a pitman arm,
drag link, tie rod, and steering dampener (Fig. 2) .
An adjustment sleeve on the tie rod is used to set
wheel toe position. The sleeve on the drag link is
used for steering wheel centering.
CAUTION: If any steering components are replaced
or serviced an alignment must be performed, to
ensure the vehicle meets all alignment specifica-
tions.
CAUTION: Components attached with a nut and cot-
ter pin must be torqued to specification. Then if the
slot in the nut does not line up with the cotter pin
hole, tighten nut until it is aligned. Never loosen the
nut to align the cotter pin hole.
19 - 26 LINKAGEWJ
Fig. 1 Right Hand Drive Steering Linkage
1 - PITMAN ARM
2 - STEERING DAMPENER
Fig. 2 Steering Linkage
1 - DRAG LINK
2 - PITMAN ARM
3 - TIE ROD END
4 - TIE ROD
5 - DAMPER
6 - TIE ROD END
WJLINKAGE 19 - 27
LINKAGE (Continued)
SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Pitman Arm
Shaft Nut251 185 Ð
Drag Link
Pitman Arm Nut88 65 Ð
Drag Link
Knuckle Nut47 35 Ð
Drag Link
Clamp Nuts41 30 Ð
Tie Rod
Knuckle Nut47 35 Ð
Tie Rod
Clamp Nuts41 30 Ð
Steering Damper
Axle Bolt88 65 Ð
Steering Damper
Tie Rod Nut41 30 Ð
SPECIAL TOOLS
STEERING LINKAGEDAMPER
DESCRIPTION
The damper is mounted to the axle housing and
the tie rod end. The damper consists of steel tube
shock absorber with a permanent bushed end.
OPERATION
The steering damper provides steering system
damping.
REMOVAL
(1) Remove the nut from the ball stud at the tie
rod.
(2) Remove the steering damper from the tie rod.
(3) Remove the steering damper nut and bolt from
the axle bracket (Fig. 3) .Puller C-3894±A
Remover Pitman C-4150A
19 - 28 LINKAGEWJ
LINKAGE (Continued)
INSTALLATION
(1) Install the steering damper to the axle bracket
and tie rod.
(2) Install the steering damper bolt in the axle
bracket and tighten bolt to 88 N´m (65 ft. lbs.).
(3) Install the nut at the tie rod and tighten to 41
N´m (30 ft. lbs.).
DRAG LINK
DESCRIPTION
The drag link and ends are comprised of two forged
ends connected by a steel adjusting tube. The drag
link connects the steering gear pitman arm to the
steering knuckle. The larger offset end is attached to
the pitman arm.
OPERATION
The sleeve is used for steering wheel centering.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove right wheel and tire assembly.
(3) Remove the cotter pins and nuts at the right
steering knuckle and pitman arm (Fig. 4) .
(4) Remove the drag link from the steering
knuckle and pitman arm Puller C-3894-A.
(5) Loosen adjustment sleeve clamp bolts and
unscrew the tie rod ends from the adjustment sleeve.
INSTALLATION
(1) Screw the tie rod ends into the adjustment
sleeve.
(2) Install the drag link onto the right steering
knuckle and pitman arm.(3) Tighten the nut at the steering knuckle to 47
N´m (35 ft. lbs.). Tighten the pitman nut to 88 N´m
(65 ft. lbs.). Install new cotter pins.
(4) Position clamp bolts to their original position
and tighten to 41 N´m (30 ft. lbs.).
(5) Install right wheel and tire assembly.
(6) Remove support and lower the vehicle.
(7) Center the steering wheel.
PITMAN ARM
DESCRIPTION
The pitman arm is attached at one end of the
steering gear's sector shaft. The other end is con-
nected to the drag link.
OPERATION
The pitman arm transfers rotary motion into side
to side motion.
REMOVAL
(1) Remove the cotter pin and nut from the drag
link at the pitman arm (Fig. 5) .
(2) Remove the drag link ball stud from the pit-
man arm with a puller.
(3) Remove the nut and washer from the steering
gear shaft. Mark the pitman shaft and pitman arm
for installation reference. Remove the pitman arm
from steering gear with Puller C-4150A.
Fig. 3 Steering Damper
1 - DAMPER
2 - TIE ROD
Fig. 4 Drag Link
1 - STEERING GEAR
2 - PITMAN ARM
3 - CLAMP
4 - DRAG LINK
5 - CLAMP
WJLINKAGE 19 - 29
DAMPER (Continued)