2003 JEEP GRAND CHEROKEE Check gauges

DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TEST
An accurate tachometer and pressure test gauges
are required. Test Gauge C-3293-SP has a 300 psi
range and is used at all locations where pressures
exceed 100 psi.
Pressure Test Port Locations
Only two pressure ports are supplied on the trans-
mission case. The torque converter clutch apply and
release ports are located on the right side of the
transmission case (Fig. 2).
To determine the line pressure, there are two avail-
able methods. The DRBtscan tool can be used to
read line pressure from the line pressure sensor. The
second method is to install Line Pressure Adapter
8259 (Fig. 4) into the transmission case and then
install the pressure gauge and the original sensor
into the adapter. This will allow a comparison of the
DRBtreadings and the gauge reading to determe the
accuracy of the line pressure sensor. The DRBtline
pressure reading should match the gauge reading
within  10 psi.
In order to access any other pressure tap locations,
the transmission oil pan must be removed, the pres-
sure port plugs removed and Valve Body Pressure
Tap Adapter 8258-A (Fig. 5) installed. The extensions
supplied with Adapter 8258-A will allow the installa-
tion of pressure gauges to the valve body. Refer to
(Fig. 3) for correct pressure tap location identifica-
tion.
TEST PROCEDURE
All pressure readings should be taken with the
transmission fluid level full, transmission oil at the
normal operating temperature, and the engine at
1500 rpm. Check the transmission for proper opera-
tion in each gear position that is in question or if a
specific element is in question, check the pressure
readings in at least two gear positions that employ
that element. Refer to the Hydraulic Schematics at
the rear of this section to determine the correct pres-
sures for each element in a given gear position.
Fig. 2 Torque Converter Pressure Locations
1 - TCC RELEASE
2 - TO COOLER
3 - TCC APPLY
4 - FROM COOLER
5 - LINE PRESSURE SENSOR
Fig. 3 Pressure Tap Locations
Fig. 4 Line Pressure Adapter 8259
1 - LINE PRESSURE SENSOR PORT
2 - LINE PRESSURE SENSOR
3 - TOOL 8259
4 - PRESSURE TAP
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 181
AUTOMATIC TRANSMISSION - 545RFE (Continued)

TIRES/WHEELS
TABLE OF CONTENTS
page page
TIRES/WHEELS
DIAGNOSIS AND TESTING - TIRE AND
WHEEL RUNOUT......................1
STANDARD PROCEDURE
STANDARD PROCEDURE - TIRE AND
WHEEL BALANCE......................2
STANDARD PROCEDURE - MATCH
MOUNTING...........................4
STANDARD PROCEDURE - TIRE ROTATION . 5
STANDARD PROCEDURE - WHEEL
INSTALLATION........................5
TIRES
DESCRIPTION
DESCRIPTION - TIRES..................6
DESCRIPTION - RADIAL±PLY TIRES.......6
DESCRIPTION - TIRE INFLATION
PRESSURES..........................6
DESCRIPTION - TIRE PRESSURE FOR
HIGH SPEED..........................7
DESCRIPTION - REPLACEMENT TIRES.....7
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRESSURE
GAUGES.............................8
DIAGNOSIS AND TESTING - TREAD WEAR
INDICATORS..........................8
DIAGNOSIS AND TESTING - TIRE WEAR
PATTERNS...........................8
DIAGNOSIS AND TESTING - TIRE NOISE
OR VIBRATION........................8STANDARD PROCEDURE - REPAIRING
LEAKS...............................8
CLEANING.............................9
SPECIFICATIONS
TIRES...............................9
SPECIFICATIONS -.....................9
SPARE TIRE
DESCRIPTION - SPARE / TEMPORARY TIRE . . 10
WHEELS
DESCRIPTION.........................10
DIAGNOSIS AND TESTING - WHEEL
INSPECTION.........................10
STANDARD PROCEDURE - WHEEL
REPLACEMENT.......................10
SPECIFICATIONS
TORQUE CHART......................11
STUDS
REMOVAL.............................11
INSTALLATION.........................11
TIRE PRESSURE MONITORING
DESCRIPTION.........................12
OPERATION...........................12
DIAGNOSIS AND TESTING - TIRE PRESSURE
MONITORING SYSTEM.................12
SENSOR
REMOVAL - TIRE PRESSURE SENSOR/
TRANSMITTER.......................12
INSTALLATION - TIRE PRESSURE SENSOR/
TRANSMITTER.......................13
TIRES/WHEELS
DIAGNOSIS AND TESTING - TIRE AND WHEEL
RUNOUT
Radial runout is the difference between the high
and low points on the tire or wheel (Fig. 1).
Lateral runout is thewobbleof the tire or wheel.
Radial runout of more than 1.5 mm (.060 inch)
measured at the center line of the tread may cause
the vehicle to shake.
Lateral runout of more than 2.0 mm (.080 inch)
measured near the shoulder of the tire may cause the
vehicle to shake.
Sometimes radial runout can be reduced. Relocate
the wheel and tire assembly on the mounting studs
(See Method 1). If this does not reduce runout to an
acceptable level, the tire can be rotated on the wheel.
(See Method 2).
METHOD 1 (RELOCATE WHEEL ON HUB)
(1) Drive vehicle a short distance to eliminate tire
flat spotting from a parked position.
(2) Check wheel bearings and adjust if adjustable
or replace if necessary.
(3) Check the wheel mounting surface.
(4) Relocate wheel on the mounting, two studs
over from the original position.
(5) Tighten wheel nuts until all are properly
torqued, to eliminate brake distortion.
(6) Check radial runout. If still excessive, mark
tire sidewall, wheel, and stud at point of maximum
runout and proceed to Method 2.
METHOD 2 (RELOCATE TIRE ON WHEEL)
NOTE: Rotating the tire on wheel is particularly
effective when there is runout in both tire and
wheel.
WJTIRES/WHEELS 22 - 1

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRESSURE
GAUGES
A quality air pressure gauge is recommended to
check tire pressure. After checking the air pressure,
replace valve cap finger tight.
DIAGNOSIS AND TESTING - TREAD WEAR
INDICATORS
Tread wear indicators are molded into the bottom
of the tread grooves. When tread depth is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band (Fig. 15).
Tire replacement is necessary when indicators
appear in two or more grooves or if localized balding
occurs.
DIAGNOSIS AND TESTING - TIRE WEAR
PATTERNS
Under inflation will cause wear on the shoulders of
tire. Over inflation will cause wear at the center of
tire.
Excessive camber causes the tire to run at an
angle to the road. One side of tread is then worn
more than the other (Fig. 16).
Excessive toe-in or toe-out causes wear on the
tread edges and a feathered effect across the tread
(Fig. 16).
DIAGNOSIS AND TESTING - TIRE NOISE OR
VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, vibration, wheel
defects, or possibly tire imbalance.
To find out if tires are causing the noise or vibra-
tion, drive the vehicle over a smooth road at varying
speeds. Note the noise level during acceleration and
deceleration. The engine, differential and exhaust
noises will change as speed varies, while the tire
noise will usually remain constant.
STANDARD PROCEDURE - REPAIRING LEAKS
For proper repairing, a radial tire must be removed
from the wheel. Repairs should only be made if the
defect, or puncture, is in the tread area (Fig. 17). The
tire should be replaced if the puncture is located in
the sidewall.
Deflate tire completely before removing the tire
from the wheel. Use lubrication such as a mild soap
solution when dismounting or mounting tire. Use
tools free of burrs or sharp edges which could dam-
age the tire or wheel rim.
Before mounting tire on wheel, make sure all rust
is removed from the rim bead and repaint if neces-
sary.
Install wheel on vehicle, and tighten to proper
torque specification (Refer to 22 - TIRES/WHEELS/
WHEELS - SPECIFICATIONS).
Fig. 15 Tread Wear Indicators
1 - TREAD ACCEPTABLE
2 - TREAD UNACCEPTABLE
3 - WEAR INDICATOR
22 - 8 TIRES/WHEELSWJ

(7) Remove the external snap ring that secures the
compressor clutch coil to the nose of the compressor
front housing with snap ring pliers and slide the coil
assembly off of the compressor (Fig. 8).
INSPECTION
Examine the friction surfaces of the clutch pulley
and the clutch plate for wear. The pulley and plate
should be replaced if there is excessive wear or scor-
ing.
If the friction surfaces are oily, inspect the shaft
and nose area of the compressor for refrigerant oil.
Remove the felt wick from around the shaft inside
the nose of the compressor front housing. If the felt
is saturated with refrigerant oil, the compressor
shaft seal is leaking and the compressor must be
replaced.
Check the clutch pulley bearing for roughness or
excessive leakage of grease. Replace the bearing, if
required.
INSTALLATION
(1) Align the dowel pin on the back of the clutch
field coil with the hole in the compressor front hous-
ing and press the field coil into place over the nose of
the compressor.
(2) Install the clutch coil lead wire harness retain-
ing clip on the compressor front housing and tighten
the retaining screw.(3) Install the clutch field coil and snap ring with
snap ring pliers (Special Tool C-4574). The bevel side
of the snap ring must be facing outward. Also, both
eyelets of the snap ring must be to the right or left of
the pin on the compressor. Press in on the snap ring
to be certain that it is properly seated in the groove.
CAUTION: If the snap ring is not fully seated in the
groove it will vibrate out, resulting in a clutch fail-
ure and severe damage to the front housing of the
compressor.
(4) Install the pulley assembly onto the compres-
sor. If necessary, place a block of wood on the friction
surface and tap gently with a hammer (Fig. 9).
CAUTION: Do not mar the pulley friction surface.
(5) Install the pulley assembly retaining snap ring
(bevel side outward) with snap ring pliers (Special
Tool C-4574). Press in on the snap ring to be certain
that it is properly seated in the groove.
(6) If the original clutch plate assembly and pulley
assembly are to be reused, the old shim(s) can be
used. If not, place a stack of shim(s) equal to the old
shim(s) on the shaft against the shoulder.
(7) Install the clutch plate assembly onto the
shaft.
(8) With the clutch plate assembly tight against
the shim(s), measure the air gap between the clutch
plate and the pulley face with feeler gauges. The air
Fig. 8 CLUTCH COIL SNAP RING
1 - SNAP RING PLIERS
2 - CLUTCH COIL
3 - SNAP RING
4 - COMPRESSOR
Fig. 9 PULLEY ASSEMBLY INSTALL
1 - PULLEY ASSEMBLY
2 - WOOD BLOCK
WJCONTROLS 24 - 15
A/C COMPRESSOR CLUTCH (Continued)