2002 JEEP GRAND CHEROKEE Steering fluid

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)

BINDING AND STICKING
CONDITION POSSIBLE CAUSE CORRECTION
DIFFICULT TO TURN WHEEL
STICKS OR BINDS1. Low fluid level. 1. Fill to proper level.
2. Tire pressure. 2. Adjust tire pressure.
3. Steering component. 3. Inspect and lube.
4. Loose belt. 4. Adjust or replace.
5. Low pump pressure. 5. Pressure test and replace if
necessary.
6. Column shaft coupler binding. 6. Replace coupler.
7. Steering gear worn or out of
adjustment.7. Repair or replace gear.
8. Ball joints binding. 8. Inspect and repair as necessary.
9. Belt routing. 9. Verify belt routing is correct.
4.7L Hydraulic fan motor steering output
lowPressure / Flow test fans steering
output flow
INSUFFICIENT ASST. OR POOR RETURN TO CENTER
CONDITION POSSIBLE CAUSE CORRECTION
HARD TURNING OR MOMENTARY
INCREASE IN TURNING EFFORT1. Tire pressure. 1. Adjust tire pressure.
2. Low fluid level. 2. Fill to proper level.
3. Loose belt. 3. Adjust or replace.
4. Lack of lubrication. 4. Inspect and lubricate steering and
suspension compnents.
5. Low pump pressure or flow. 5. Pressure and flow test and repair
as necessary.
6. Internal gear leak. 6. Pressure and flow test, and repair
as necessary.
7. Belt routing. 7. Verify belt routing is correct.
4.7L8. Low flow / pressure from fan
motor8. Pressure and flow test and repair
as necessary.
STEERING WHEEL
DOES NOT WANT TO RETURN TO
CENTER POSITION1. Tire pressure. 1. Adjust tire pressure.
2. Wheel alignment. 2. Align front end.
3. Lack of lubrication. 3. Inspect and lubricate steering and
suspension compnents.
4. High friction in steering gear. 4. Test and adjust as necessary.
5. Ball joints binding. 5. Inspect and repair as necessary.
NOTE:
Some roads will cause a vehicle to drift, due to the crown in the road.
WJSTEERING 19 - 3
STEERING (Continued)

(8) Start engine and let idle long enough to circu-
late power steering fluid through flow/pressure test
gauge.
(9) Shut off the engine and check the fluid level,
add fluid as necessary. Start engine again and let
idle.
(10) The initial pressure reading should be
345-552 kPa (50-80 psi). If pressure is higher inspect
the hoses for restrictions and repair as necessary.
(11) Increase the engine speed to 1500 RPM and
read the flow meter. The reading should be 2.4 - 2.8
GPM, if the reading is below this specification the
pump should be replaced.
CAUTION: This next step involves testing maximum
pump pressure output and flow control valve oper-
ation. Do not leave valve closed for more than three
seconds as the pump could be damaged.
(12) Close valve fully three times for three seconds
and record highest pressure indicated each time.All
three readings must be at pump relief pressure
specifications and within 345 kPa (50 psi) of
each other.
²Pressures above specifications but not within
345 kPa (50 psi) of each other, replace pump.
²Pressures within 345 kPa (50 psi) of each other
but below specifications, replace pump.
CAUTION: Do not force the pump to operate against
the stops for more than 2 to 4 seconds at a time
because, pump damage will result.
(13) Open the test valve and turn the steering
wheel to the extreme left and right positions against
the stops. Record the highest pressure reading at
each position. Compare readings to the pump specifi-
cations chart. If pressures readings are not within 50
psi. of each other, the gear is leaking internally and
must be repaired.
GEAR INLET SPECIFICATIONS 4.0L & 4.7L
ENGINERELIEF
PRESSURE   50FLOW RATE
(GPM)
4.0L 9653 kPa (1400 psi)
1500 RPM 2.4 - 2.8
GPM
4.7L 9653 kPa (1450 psi)
PUMP MOTOR SPECIFICATIONS 4.7L
ENGINERELIEF
PRESSURE   50FLOW RATE
(GPM)
4.7L 9653 kPa (1900 psi)1100 RPM 2.4-2.8
GPM Minium
@ 200 psi
DIAGNOSIS AND TESTING - 4.7L -
HYDRAULIC
The following procedures are used to test the oper-
ation of the power steering and hydraulic fan sys-
tems on the vehicle. This test will provide the gallons
per minute (GPM) or flow rate of the power steering
pump along with any maximum relief pressure. Per-
form test anytime a power steering system problem
is present. This test will determine if the power
steering pump, hydraulic fan, and power steering
gear are not functioning properly. It will also deter-
mine if the flow coming out of the hydraulic fan
motor is sufficient for the power steering gear. The
following pressure and flow test is performed using
the Power Steering Analyzer Tool kit 6815 (Fig. 2)
and Adapter kit 8630 (Fig. 3).
FLOW TEST - FLOW FROM POWER STEERING
PUMP
(1) Check the power steering belt to ensure it is in
good condition and adjusted properly.
(2) Connect the pressure gauge hose from the
Power Steering Analyzer to Tube 8630-2.
(3) Connect Adapter 8630-3 to Power Steering
Analyzer test valve end.
(4) Disconnect the high pressure hose from the
power steering pump.
(5) Connect Tube 8630-2 to the pump hose fitting.
(6) Connect the power steering hose from the fan
motor to Adapter 8630-3.
(7) Open the test valve completely.
(8) Start engine and let idle long enough to circu-
late power steering fluid through the flow/pressure
test gauge.
(9) Shut off the engine and check the fluid level,
add fluid ass necessary. Start engine again and let
idle.
(10) The initial pressure reading should be 483 -
690 kPa (70 - 100 psi). If pressure is higher inspect
the hoses for restrictions and repair as necessary.
Fig. 3 4.7L HYDRAULIC POWER STEERING TEST
ADAPTERS
WJSTEERING 19 - 5
STEERING (Continued)

(11) Increase the engine speed to 1100 rpm and
read the flow meter. The reading should be 2.6 GPM
minimum, if the reading is below this specification,
the pump should be replaced.
FLOW AND PRESSURE TEST - FLOW FROM
HYDRAULIC FAN MOTOR TO STEERING GEAR
(should be done if necessary after the Pump flow
test)
(1) Connect the pressure gauge hose from the
Power Steering Analyzer to Fitting 8630-1.
(2) Connect Adapter 8630-4 to Power Steering
Analyzer test valve end.
(3) Disconnect the high pressure hose from the
power steering gear.
(4) Connect Fitting 8630-1 to the high pressure
hose.
(5) Connect Adapter 8630-4 to the power steering
gear.
(6) Open the test valve completely.
(7) Start engine and let idle long enough to circu-
late power steering fluid through the flow/pressure
test gauge.
(8) Shut off the engine and check the fluid level,
add fluid ass necessary. Start engine again and let
idle.
(9) The initial pressure reading should be 345-552
kPa (50-80 psi). If pressure is higher inspect the
hoses for restrictions and repair as necessary.(10) Increase the engine speed to 1500 RPM and
read the flow meter. The reading should be 2.4 - 2.8
GPM if the reading is below this specification the fan
should be replaced.
CAUTION: This next step involves testing maximum
fan motor steering relief pressure. Do not leave the
valve closed for more than three seconds.
(11) Close the valve fully three times for three sec-
onds and record highest pressures indicated each
time. All three readings must be at fan motor steer-
ing relief pressures.
(12) Open the test valve and turn the steering
wheel to the extreme left and right positions against
the stops. Record the highest pressure readings at
each position. If pressure readings are not within 50
psi from each other, the gear is leaking internally
and must be repaired.
PUMP MOTOR SPECIFICATIONS 4.7L
ENGINERELIEF
PRESSURE   50FLOW RATE
(GPM)
4.7L 9653 kPa (1900 psi)1100 RPM 2.4-2.8
GPM Minium
@ 200 psi
19 - 6 STEERINGWJ
STEERING (Continued)

ADJUSTMENTS
STEERING GEAR
NOTE: Adjusting the steering gear in the vehicle is
not recommended. Remove gear from the vehicle
and drain the fluid. Then mount gear in a vise to
perform adjustments.
OVER-CENTER
(1) Rotate the stub shaft with Socket 8343 from
stop to stop and count the number of turns.
(2) Center the stub shaft by rotating it from the
stop 1/2 of the total amount of turns.
(3) Place torque wrench and Socket 8343 in a ver-
tical position on the stub shaft. Rotate the wrench 45
degrees each side of the center and record the high-
est rotational torque in this range (Fig. 4) . This is
the Over-Center Rotating Torque.
NOTE: The stub shaft must rotate smoothly without
sticking or binding.
(4) Rotate the stub shaft between 90É and 180É to
the left of center and record the left off-center pre-
load. Repeat this to the right of center and record the
right off-center preload. The average of these two
recorded readings is the Preload Rotating Torque.
(5) The Over-Center Rotating Torque should be
0.45-0.80 N´m (4-7 in. lbs.)higherthan the Preload
Rotating Torque.
(6) If an adjustment to the Over-Center Rotating
Torque is necessary, first loosen the adjuster lock
nut. Then turn the pitman shaft adjuster screw back
(COUNTERCLOCKWISE) until fully extended, then
turn back in (CLOCKWISE) one full turn.
(7) Remeasure Over-Center Rotating Torque. If
necessary turn the adjuster screw and repeat mea-
surement until correct Over-Center Rotating Torque
is reached.
NOTE: To increase the Over-Center Rotating Torque
turn the screw CLOCKWISE.(8) Prevent the adjuster screw from turning while
tightening adjuster lock nut. Tighten the adjuster
lock nut to 37-52 N´m (27-38 ft. lbs.).
SPECIFICATIONS
POWER STEERING GEAR
SPECIFICATIONS
DESCRIPTION SPECIFICATION
Steering Gear
TypeRecirculating Ball
Steering Gear
Overall Ratio12.7:1
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Pitman Shaft Overcenter Drag
New Gear (under 400 miles)0.45-0.80
+ Worm Shaft PreloadÐ 4-7
+ Worm Shaft Preload
Pitman Shaft Overcenter Drag
Used Gear (over 400 miles)0.5-0.6
+ Worm Shaft PreloadÐ 4-5
+ Worm Shaft Preload
Fig. 4 Checking Over-center Rotation Torque
1 - CENTER
19 - 18 GEARWJ
GEAR (Continued)

INSTALLATION
(1) Lubricate new o-ring and teflon rings with
power steering fluid and install on the rack piston/
valve assembly.
(2) Lubricate the rack piston/valve assembly with
power steering fluid.
(3) Slide the assembly into the gear housing.
(4) Install new stub shaft housing o-rings and
install the housing. Tighten the housing bolts to 62
N´m (46 ft. lbs.).
(5) Install new o-ring on the pitman shaft cover.
(6) Install the pitman shaft into the gear housing.
(7) Install the pitman shaft cover bolts and tighten
to 62 N´m (46 ft. lbs.).
(8) Perform over-center rotation torque adjustment
(Refer to 19 - STEERING/GEAR - ADJUSTMENTS)..
(9) Install the steering gear (Refer to 19 - STEER-
ING/GEAR - INSTALLATION).
(10) Fill the power steering pump (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
STUB SHAFT HOUSING
REMOVAL
NOTE: If stub shaft housing, seal or bearing is dam-
aged the housing must be replaced.
(1) Remove the steering gear (Refer to 19 -
STEERING/GEAR - REMOVAL).
(2) Remove stub shaft housing bolts (Fig. 19).
(3) Remove housing from the steering gear (Fig.
20).
(4) Remove stub shaft housing o-rings (Fig. 15).
INSTALLATION
NOTE: If stub shaft housing, seal or bearing is dam-
aged the housing must be replaced.
(1) Grease stub shaft seal withspecial grease-
supplied with new stub shaft housing.
(2) Install new stub shaft housing o-rings.
(3) Install housing on the steering gear.
(4) Install the housing bolts and tighten to 62 N´m
( 46 ft. lbs.).
(5) Install the steering gear (Refer to 19 - STEER-
ING/GEAR - INSTALLATION).
(6) Fill the power steering pump (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
Fig. 19 Stub Shaft Housing
1 - STUB SHAFT HOUSING
2 - BOLTS
3 - STUB SHAFT
Fig. 20 Housing Removal
1 - STEERING GEAR
2 - HOUSING
WJGEAR 19 - 25
RACK PISTON/VALVE ASSEMBLY (Continued)

PUMP
TABLE OF CONTENTS
page page
PUMP
DESCRIPTION - 4.0L, 4.7L................32
OPERATION
OPERATION - 4.7L....................32
OPERATION - 4.0L....................32
DIAGNOSIS AND TESTING - PUMP LEAKAGE . 33
STANDARD PROCEDURE
STANDARD PROCEDURE - INITIAL
OPERATION - 4.0L....................33
STANDARD PROCEDURE - INITIAL
OPERATION - 4.7L....................33
REMOVAL
REMOVAL - 4.0L ENGINE...............34
REMOVAL - 4.7L ENGINE...............34
INSTALLATION
INSTALLATION - 4.0L ENGINE...........34
INSTALLATION - 4.7L ENGINE...........34
SPECIFICATIONS
TORQUE CHART......................35
SPECIAL TOOLS
POWER STEERING PUMP..............36
FLUID COOLER
DESCRIPTION.........................36
REMOVAL.............................36
INSTALLATION.........................37
HOSES - 4.0L
DESCRIPTION
DESCRIPTION - PRESSURE LINE........37
DESCRIPTION - RETURN LINE...........37
OPERATION
OPERATION - PRESSURE LINE..........37
OPERATION - RETURN LINE............37
REMOVAL.............................37
INSTALLATION.........................37
HOSES - 4.7L
DESCRIPTION
DESCRIPTION - 1/2º PRESSURE HOSE....38DESCRIPTION - 1/2º RETURN HOSE......38
DESCRIPTION - 3/8º PRESSURE HOSE....38
DESCRIPTION - 3/8º GEAR OUTLET HOSE . 38
DESCRIPTION - 3/8º RETURN HOSE......38
OPERATION
OPERATION - 1/2º PRESSURE HOSE......38
OPERATION - 1/2º RETURN HOSE........38
OPERATION - 3/8º PRESSURE HOSE......39
OPERATION - 3/8º GEAR OUTLET HOSE . . . 39
OPERATION - 3/8ºRETURN HOSE........39
REMOVAL
REMOVAL - 1/29PRESSURE HOSE.......39
REMOVAL - 1/29RETURN HOSE..........39
REMOVAL - 3/89PRESSURE HOSE.......39
REMOVAL - 3/89RETURN HOSE..........39
REMOVAL - 3/89GEAR OUTLET HOSE.....40
REMOVAL - INLET COOLER HOSE........40
REMOVAL - OUTLET COOLER HOSE......40
INSTALLATION
INSTALLATION - 1/29PRESSURE HOSE....40
INSTALLATION - 1/29RETURN HOSE......40
INSTALLATION - 3/89PRESSURE HOSE....41
INSTALLATION - 3/89RETURN HOSE......41
INSTALLATION - 3/89GEAR OUTLET HOSE . 41
INSTALLATION - INLET COOLER HOSE....41
INSTALLATION - OUTLET COOLER HOSE . . 41
PULLEY
DESCRIPTION
POWER STEERING PUMP PULLEY - 3.1L
DIESEL.............................41
REMOVAL.............................41
INSTALLATION.........................42
RESERVOIR
REMOVAL.............................42
INSTALLATION.........................42
WJPUMP 19 - 31

PUMP
DESCRIPTION - 4.0L, 4.7L
Hydraulic pressure for the power steering system
is provided by a belt driven power steering pump
(Fig. 1) and (Fig. 2). The pump shaft has a
pressed-on drive pulley that is belt driven by the
crankshaft pulley.
OPERATION
OPERATION - 4.7L
The power steering pump is a constant flow rate
and displacement, vane-type pump. The pump has
internal parts that operate submerged in fluid. The
flow control orifice and the pressure relief valve,
which limits the pump pressure, are internal to the
pump. The reservoir is attached to the pump body
with spring clips. The power steering pump is used
to drive the hydraulic engine cooling fan, which sep-
arates the flow to the fan gerotors and the power
steering gear. The power steering pump is connected
to the engine cooling fan by pressure and return
hoses and the pump is connected to the steering gear
via a return hose from the steering cooler (Fig. 2).NOTE: Power steering pumps have different pres-
sure rates and are not interchangeable with other
pumps.OPERATION - 4.0L
The power steering pump is a constant flow rate
and displacement, vane-type pump. The pump inter-
nal parts operate submerged in fluid. The flow con-
trol orifice is part of the high pressure line fitting.
The pressure relief valve inside the flow control valve
limits the pump pressure. The reservoir is attached
to the pump body with spring clips. The power steer-
ing pump is connected to the steering gear by the
pressure and return hoses (Fig. 1).
NOTE: Power steering pumps have different pres-
sure rates and are not interchangeable with other
pumps.
Fig. 1 Pump With Integral Reservoir
1 - CAP
2 - FLUID RESERVOIR (TYPICAL)
3 - HIGH-PRESSURE FITTING
4 - DRIVE PULLEY
5 - PUMP BODY
6 - RESERVOIR CLIP
Fig. 2 4.7L POWER STEERING PUMP
1 - PRESSURE HOSE QUICK CONNECT NUT
2 - CAP
3 - FLUID RESERVOIR
4 - LOW-PRESSURE RETURN FROM THE COOLER
5 - LOW-PRESSURE RETURN FROM THE HYDRAULIC FAN
DRIVE
6 - PUMP BODY
7 - HIGH PRESSURE FITTING
19 - 32 PUMPWJ