Brake line JEEP GRAND CHEROKEE 2003 WJ / 2.G Service Manual

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Coil On Plug NO. 8 (4.7L) BK Right Side of Engine Near Fuel
Injector No.814, 15
Coil Rail (4.0L) BK Right Rear of Engine 10, 11
Compact Disc Changer BK Near Radio N/S
Compact Disc Changer BK Right Rear Quarter Panel 37
Controller Antilock Brake BK Left Front Engine Compartment 3, 4
Coolant Level Sensor LT GY Right Rear of Engine 5
Crankcase Heater (Diesel) BK Near T/O for G105 8
Crankshaft Position Sensor
(Diesel)BK Rear of Engine Near Transmission
Bell HousingN/S
Crankshaft Position Sensor
(Gas)BK Rear of Engine Near Transmission
Bell Housing10, 11, 14, 15, 17
Data Link Connector BK Under Lower Driver's Side of
Instrument Panel20, 21, 22
Diagnostic Junction Port BK At Steering Column 23
Driver Airbag Squib 1 BK In Steering Wheel N/S
Driver Airbag Squib 2 BK In Steering Wheel N/S
Driver Blend Door Motor/
Actuator (AZC)BK On HVAC Housing N/S
Driver Cylinder Lock Switch GY In Driver Door 24, 25
Driver Door Lock Motor/Ajar
SwitchBK In Driver Door 24, 25
Driver Door Module - C1 WT In Driver Door 24, 25
Driver Door Module - C2 BK In Driver Door N/S
Driver Door Module - C3 BK In Driver Door N/S
Driver Front Door Courtesy
LampBK In Driver Door N/S
Driver Front Power Window
MotorBK In Driver Door 24, 25
Driver Heated Seat Back
(Premium I/III)GN At Driver Seat N/S
Driver Heated Seat Cushion
(Premium I/III)BK At Driver Seat N/S
Driver Heated Seat Switch WT Center of Instrument Panel 19 20, 21
Driver Lumbar Motor
(Midline/Premium)BK At Driver Seat N/S
Driver Lumbar Switch
(Midline/Premium)WT At Driver Seat N/S
Driver Power Mirror BK At Driver Door N/S
Driver Power Seat Front Riser
MotorRD At Driver Seat N/S
Driver Power Seat Front Riser
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Horizontal
MotorBK At Driver Seat N/S
8W - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONWJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Driver Power Seat Horizontal
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Rear Riser
MotorRD At Driver Seat N/S
Driver Power Seat Rear Riser
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Recliner
MotorBK At Driver Seat N/S
Driver Power Seat Recliner
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Switch
(Midline/Premium)GN At Driver Seat N/S
Driver Rear Power Window
MotorBK In Left Rear Door 28
Driver Rear Power Window
SwitchBL In Left Rear Door 28
Driver Seat Belt Switch At Switch N/S
EGR Solenoid (Diesel) BK Left Front Fender 7, 8
Electric Brake BL Near Junction Block N/S
Electronic Speed Control Servo BK Right Front of Engine Compartment 5
Engine Control Module C1
(Diesel)BK Left Front of Engine 7, 8
Engine Control Module C2
(Diesel)BK Left Front of Engine 7, 8
Engine Coolant Temperature
Sensor (Diesel)BK Top of Engine N/S
Engine Coolant Temperature
Sensor (GAS)BK Front of Engine 9, 13
Engine Oil Pressure Sensor BK Side of Engine 10, 11, 13
EVAP/Purge Solenoid BK Left Front Fender Near Controller
Antilock Brake3
Front Power Outlet RD Center of Instrument Panel 19, 20
Front Washer Pump WT Left Front of Engine Compartment 3, 4
Front Wiper Motor BK Left Side of Cowl 3, 4
Fuel Injector No.1 BK At Injector 7, 9, 13
Fuel Injector No.2 BK At Injector 7, 9, 14, 15
Fuel Injector No.3 BK At Injector 7, 9, 13
Fuel Injector No.4 BK At Injector 7, 9, 14, 15
Fuel Injector No.5 BK At Injector 9, 13
Fuel Injector No.6 BK At Injector 9, 14, 15
Fuel Injector No.7 (4.7L) BK At Injector 13
Fuel Injector No.8 (4.7L) BK At Injector 14, 15
Fuel Pressure Sensor (Diesel) BK Right Front of Engine N/S
Fuel Pressure Solenoid
(Diesel)BK Top of Engine N/S
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 5
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Output Speed Sensor (4.0L) GY Left Side of Transmission 12
Output Speed Sensor (4.7L) BK Left Side of Transmission 16
Overhead Map/Courtesy Lamp WT At Overhead Console N/S
Oxygen Sensor 1/1 Upstream
(4.0L)GY Left Side of Engine at Exhaust 9, 12
Oxygen Sensor 1/1 Upstream
(4.7L)GY Left Side of Engine at Exhaust 17
Oxygen Sensor 1/2
Downstream (4.0L)BK Rear of Transmission 9, 12
Oxygen Sensor 1/2
Downstream (4.7L)BK Rear of Transmission 17
Oxygen Sensor 2/1 Upstream Rear of Transmission N/S
Oxygen Sensor 2/2
DownstreamRear of Transmission N/S
Park Brake Switch Center Console Area, Near Airbag
Control Module20, 21, 22
Park/Neutral Position Switch
(4.0L)BK Left Side of Transmission 12
Park/Neutral Position Switch
(Diesel)BK Left Side of Transmission N/S
Passenger Airbag YL Passenger Side of Instrument Panel 19, 20
Passenger Blend Door
Motor/Actuator (AZC)BK Passenger Side of Instrument Panel N/S
Passenger Door Lock
Motor/Ajar SwitchBK In Passenger Door 26, 27
Passenger Door Module - C1 WT In Passenger Door 26, 27
Passenger Door Module - C2 BK In Passenger Door N/S
Passenger Front Door
Courtesy LampBK In Passenger Door N/S
Passenger Front Power
Window MotorBK In Passenger Door 26, 27
Passenger Heated Seat Back
(Premium I/III)GN At Passenger Seat N/S
Passenger Heated Seat
Cushion (Premium I/III)BK At Passenger Seat N/S
Passenger Heated Seat Switch BK Center of Instrument Panel 19, 20, 21
Passenger Lumbar Motor
(Midline/Premium)BK At Passenger Seat N/S
Passenger Lumbar Switch
(Midline/Premium)WT At Passenger Seat N/S
Passenger Power Mirror BK In Passenger Door N/S
Passenger Power Seat Front
Riser MotorRD At Passenger Seat N/S
Passenger Power Seat
Horizontal MotorRD At Passenger Seat N/S
8W - 91 - 8 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONWJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Passenger Power Seat Rear
Riser MotorRD At Passenger Seat N/S
Passenger Power Seat
Recliner Motor (Midline/
Premium)BK At Passenger Seat N/S
Passenger Power Seat Switch
(Midline/Premium)GN At Passenger Seat N/S
Passenger Rear Power
Window MotorBK In Right Rear Door 29
Passenger Rear Power
Window SwitchBL In Right Rear Door 29
Passenger Seat Belt Switch t Switch N/S
Power Amplifier - C1 WT Under Rear Seat 34, 36
Power Amplifier - C2 WT Under Rear Seat 34, 36
Power Connector WT Center of Instrument Panel 21, 22
Powertrain Control Module -
C1 (Gas)BK Rear of Engine Compartment 5, 10, 11, 14, 15, 18
Powertrain Control Module -
C2 (Gas)WT Rear of Engine Compartment 5, 10, 11, 14, 15, 18
Powertrain Control Module -
C3 (Gas)WT Rear of Engine Compartment N/S
Radiator Fan Motor BK At Radiator 5
Radiator Fan Relay BK Right Side of Engine Compartment 5
Radio - C1 GY Center of Instrument Panel 19, 20
Radio - C2 BK Center of Instrument Panel 19, 20
Rain Sensor BK Front Center Overhead N/S
Rear Power Outlet RD Right Rear Quarter Panel 37
Rear Washer Pump BK Left Front of Engine Compartment 3, 4
Rear Window Defogger BK Right Upper Coner of Liftgate 38
Rear Wiper Motor BK In Liftgate 38
Recirculation Door Motor/
Actuator (AZC)BK Center of Instrument Panel N/S
Red Brake Warning Indicator
SwitchGY At Master Cylinder 4
Remote Keyless Module
(Japan)BL In Driver Door 25
Right Courtesy Lamp BK At Lamp 20 21, 22
Right Curtain Airbag BK Near Right C Pillar 37
Right Door Handle Courtesy
LampBK At Lamp N/S
Right Fog Lamp BK At Right Front Fascia 5
Right Front Door Speaker WT In Right Front Door 25, 26
Right Front Impact Sensor BK Near Right Verticle Radiator Support N/S
Right Front Park Lamp WT At Lamp N/S
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 9
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

INSTALLATION
A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
(1) Install the oil pump on the cylinder block using
a replacement gasket. Tighten the bolts to 23 N´m
(17 ft. lbs.) torque.
(2) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(3) Fill the oil pan with oil to the specified level.
INTAKE MANIFOLD
DESCRIPTION
The intake manifold (Fig. 83) is made of cast alu-
minum and uses eleven bolts to mount to the cylin-
der head. This mounting style improves sealing and
reduces the chance of leaks.
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
NOTE: THE ENGINE INTAKE AND EXHAUST MANI-
FOLD MUST BE REMOVED AND INSTALLED
TOGETHER. THE MANIFOLDS USE A COMMON
GASKET AT THE CYLINDER HEAD.
(1) Disconnect the battery negative cable.
(2) Remove air cleaner inlet hose from the resona-
tor assembly.
(3) Remove the air cleaner assembly.
(4) Remove the throttle cable, vehicle speed control
cable (if equipped) and the transmission line pres-
sure cable (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - AW4/THROTTLE VALVE
CABLE - REMOVAL).
(5) Disconnect the following electrical connections
and secure their harness out of the way:
²Throttle Position Sensor
²Idle Air Control Motor
²Coolant Temperature Sensor (at thermostat
housing)
²Intake Air Temperature Sensor
²Oxygen Sensor
²Crank Position Sensor
²Six (6) Fuel Injector Connectors
²Manifold Absolute Pressure (MAP) Sensor.
(6) Disconnect HVAC, and Brake Booster vacuum
supply hoses at the intake manifold.
(7) Perform the fuel pressure release procedure.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(8) Disconnect and remove the fuel system supply
line from the fuel rail assembly.
(9) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(10) Remove the power steering pump from the
intake manifold and set aside.
(11) Raise the vehicle.
(12) Disconnect the exhaust pipes from the engine
exhaust manifolds.
(13) Lower the vehicle.
(14) Remove the intake manifold and exhaust
manifold bolts and manifolds (Fig. 84).
INSTALLATION
If the manifold is being replaced, ensure all the fit-
ting, etc. are transferred to the replacement mani-
fold.
(1) Install a new engine exhaust/intake manifold
gasket over the alignment dowels on the cylinder
head.
(2) Position the engine exhaust manifolds to the
cylinder head. Install fastener Number 3 and finger
tighten at this time (Fig. 84).
Fig. 83 Intake Manifold 4.0L Engine
WJENGINE - 4.0L 9 - 57
OIL PUMP (Continued)

INTAKE MANIFOLD
DESCRIPTION
The intake manifold is made of a composite mate-
rial and features long runners which maximizes low
end torque. The intake manifold uses single plane
sealing which consist of eight individual press in
place port gaskets to prevent leaks. Eight studs and
two bolts are used to fasten the intake to the head.
DIAGNOSIS AND TESTINGÐINTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove air cleaner housing and throttle body
resonator (Fig. 104).
(3) Disconnect throttle and speed control cables.
(4) Disconnect electrical connectors for the follow-
ing components:
²Manifold Absolute Pressure (MAP) Sensor
²Intake Air Temperature (IAT) Sensor
²Throttle Position (TPS) Sensor
²Coolant Temperature (CTS) Sensor
²Idle Air Control (IAC) Motor
(5) Disconnect vapor purge hose, brake booster
hose, speed control servo hose, positive crankcase
ventilation (PCV) hose.
Fig. 102 Measuring Clearance Over Rotors
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Fig. 103 Oil Pump and Primary Timing Chain
Tensioner Tightening Sequence
Fig. 104 Throttle Body Resonator
1 - THROTTLE BODY RESONATOR
2 - BOLT
3 - BOLT
9 - 136 ENGINE - 4.7LWJ
OIL PUMP (Continued)

(8) Inspect system body grounds for loose or dirty
connections. Refer to Group 8, Wiring for ground
locations.
(9) Verify crankcase ventilation (CCV) operation.
Refer to Emission Control System for additional
information.
(10) Inspect all fuel line quick-connect fittings for
damage or leaks.
(11) Verify hose connections to all ports of vacuum
fittings on intake manifold, and for emission system
are tight and not leaking.
(12) Inspect accelerator cable, transmission throt-
tle cable (if equipped) and speed control cable connec-
tions (if equipped). Check their connections to
throttle body linkage for any binding or restrictions.
(13) Verify vacuum booster hose is firmly con-
nected to fitting on intake manifold. Also check con-
nection to brake vacuum booster.(14) Inspect air cleaner inlet and air cleaner ele-
ment for dirt or restrictions.
(15) Inspect radiator grille area, radiator fins and
air conditioning condenser for restrictions.
(16) 4.0L Engine: Verify MAP, Intake Manifold Air
Temperature (IAT) sensor, TPS and Idle Air Control
(IAC) motor connectors are firmly connected (Fig. 9).
Be sure throttle body mounting bolts (Fig. 9)are
tight.
(17) 4.7L Engine: Verify Intake Manifold Air Tem-
perature (IAT) sensor, TPS and Idle Air Control (IAC)
motor connectors are firmly connected (Fig. 10). Be
sure throttle body mounting bolts (Fig. 10)are tight.
Fig. 8 Crankshaft Position SensorÐ4.7L V-8 Engine
1 - CRANKSHAFT POSITION SENSOR
2-STARTER
3 - ELEC. CONNECTOR
Fig. 9 IAT, MAP, IAC, TPS Sensor LocationsÐ4.0L
Engine
1 - MOUNTING BOLTS (4)
2 - THROTTLE BODY
3 - IAC MOTOR
4 - ELEC. CONN.
5 - TPS
6 - MAP SENSOR
7 - ELEC. CONN.
8 - IAT SENSOR
9 - ELEC. CONN.
14 - 34 FUEL INJECTIONWJ
FUEL INJECTION (Continued)

Test Four - Transmission In Reverse
NOTE: This test checks pump output, pressure reg-
ulation and the front clutch and rear servo circuits.
Use 300 psi Test Gauge C-3293-SP for this test.
(1) Leave vehicle on hoist and leave gauge C-3292
in place at accumulator port.
(2) Move 300 psi Gauge C-3293-SP back to rear
servo port.
(3) Have helper start and run engine at 1600 rpm
for test.
(4) Move transmission shift lever four detents
rearward from full forward position. This is Reverse
range.
(5) Move transmission throttle lever fully forward
then fully rearward and note reading at Gauge
C-3293-SP.
(6) Pressure should be 145 - 175 psi (1000-1207
kPa) with throttle lever forward and increase to 230 -
280 psi (1586-1931 kPa) as lever is gradually moved
rearward.
Test Five - Governor Pressure
NOTE: This test checks governor operation by mea-
suring governor pressure response to changes in
vehicle speed. It is usually not necessary to check
governor operation unless shift speeds are incor-
rect or if the transmission will not downshift. The
test should be performed on the road or on a hoist
that will allow the rear wheels to rotate freely.
(1) Move 100 psi Test Gauge C-3292 to governor
pressure port.
(2) Move transmission shift lever two detents rear-
ward from full forward position. This is D range.
(3) Have helper start and run engine at curb idle
speed. Then firmly apply service brakes so wheels
will not rotate.
(4) Note governor pressure:
²Governor pressure should be no more than 20.6
kPa (3 psi) at curb idle speed and wheels not rotat-
ing.
²If pressure exceeds 20.6 kPa (3 psi), a fault
exists in governor pressure control system.
(5) Release brakes, slowly increase engine speed,
and observe speedometer and pressure test gauge (do
not exceed 30 mph on speedometer). Governor pres-
sure should increase in proportion to vehicle speed.
Or approximately 6.89 kPa (1 psi) for every 1 mph.
(6) Governor pressure rise should be smooth and
drop back to no more than 20.6 kPa (3 psi), after
engine returns to curb idle and brakes are applied to
prevent wheels from rotating.
(7) Compare results of pressure test with analysis
chart.Test Six - Transmission In Overdrive Fourth Gear
NOTE: This test checks line pressure at the over-
drive clutch in fourth gear range. Use 300 psi Test
Gauge C-3293-SP for this test. The test should be
performed on the road or on a chassis dyno.
(1) Remove tachometer; it is not needed for this
test.
(2) Move 300 psi Gauge to overdrive clutch pres-
sure test port. Then remove other gauge and reinstall
test port plug.
(3) Lower vehicle.
(4) Turn OD switch on.
(5) Secure test gauge so it can be viewed from
drivers seat.
(6) Start engine and shift into D range.
(7) Increase vehicle speed gradually until 3-4 shift
occurs and note gauge pressure.
(8) Pressure should be 469-496 kPa (68-72 psi)
with closed throttle and increase to 620-827 kPa (90-
120 psi) at 1/2 to 3/4 throttle. Note that pressure can
increase to around 896 kPa (130 psi) at full throttle.
(9) Return to shop or move vehicle off chassis
dyno.
PRESSURE TEST ANALYSIS CHART
TEST CONDITION INDICATION
Line pressure OK during
any one testPump and regulator
valve OK
Line pressure OK in R
but low in D, 2, 1Leakage in rear clutch
area (seal rings, clutch
seals)
Pressure low in D Fourth
Gear RangeOverdrive clutch piston
seal, or check ball
problem
Pressure OK in 1, 2 but
low in D3 and RLeakage in front clutch
area
Pressure OK in 2 but low
in R and 1Leakage in rear servo
Front servo pressure in 2 Leakage in servo; broken
servo ring or cracked
servo piston
Pressure low in all
positionsClogged filter, stuck
regulator valve, worn or
faulty pump, low oil level
Governor pressure too
high at idle speedGovernor pressure
solenoid valve system
fault. Refer to diagnostic
book.
21 - 14 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

(8) Engine starts must be possible with shifter
lever in PARK or NEUTRAL gate positions only.
Engine starts must not be possible in any other gate
positions other than PARK or NEUTRAL.
(9) With shifter lever handle push-button not
depressed and lever detent in:
²PARK position- apply forward force on center of
handle and remove pressure. Engine start must be
possible.
²PARK position- apply rearward force on center
of handle and remove pressure. Engine start must be
possible.
²NEUTRAL position- engine start must be possi-
ble.
²NEUTRAL position, engine running and brakes
applied- Apply forward force on center of shift han-
dle. Transmission should not be able to shift into
REVERSE detent.
ELECTRONIC GOVERNOR
DESCRIPTION
Governor pressure is controlled electronically. Com-
ponents used for governor pressure control include:
²Governor body
²Valve body transfer plate
²Governor pressure solenoid valve
²Governor pressure sensor
²Fluid temperature thermistor
²Throttle position sensor (TPS)
²Transmission speed sensor
²Powertrain control module (PCM)
GOVERNOR PRESSURE SOLENOID VALVE
The solenoid valve is a duty-cycle solenoid which
regulates the governor pressure needed for upshifts
and downshifts. It is an electro-hydraulic device
located in the governor body on the valve body trans-
fer plate (Fig. 73).
GOVERNOR PRESSURE SENSOR
The governor pressure sensor measures output
pressure of the governor pressure solenoid valve (Fig.
74).
GOVERNOR BODY AND TRANSFER PLATE
The transfer plate is designed to supply transmis-
sion line pressure to the governor pressure solenoid
valve and to return governor pressure.
The governor pressure solenoid valve is mounted in
the governor body. The body is bolted to the lower
side of the transfer plate (Fig. 74).
GOVERNOR PRESSURE CURVES
There are four governor pressure curves pro-
grammed into the transmission control module. The
different curves allow the control module to adjust
governor pressure for varying conditions. One curve
is used for operation when fluid temperature is at, or
below, ±1ÉC (30ÉF). A second curve is used when fluid
temperature is at, or above, 10ÉC (50ÉF) during nor-
mal city or highway driving. A third curve is used
during wide-open throttle operation. The fourth curve
is used when driving with the transfer case in low
range.
OPERATION
Compensation is required for performance varia-
tions of two of the input devices. Though the slope of
the transfer functions is tightly controlled, offset may
vary due to various environmental factors or manu-
facturing tolerances.
The pressure transducer is affected by barometric
pressure as well as temperature. Calibration of the
zero pressure offset is required to compensate for
shifting output due to these factors.
Fig. 73 Governor Pressure Solenoid Valve
1 - SOLENOID FILTER
2 - GOVERNOR PRESSURE SOLENOID
Fig. 74 Governor Pressure Sensor
1 - GOVERNOR BODY
2 - GOVERNOR PRESSURE SENSOR/TRANSMISSION FLUID
TEMPERATURE THERMISTOR
WJAUTOMATIC TRANSMISSION - 42RE 21 - 65
BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM (Continued)

(1) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.
(2) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to reverse flush cooler and lines after
repair
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failure
due to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The transmission cooler and lines should be
reverse flushed whenever a malfunction generates
sludge and/or debris. The torque converter should
also be replaced at the same time.
Failure to flush the cooler and lines will result in
recontamination. Flushing applies to auxiliary coolers
as well. The torque converter should also be replaced
whenever a failure generates sludge and debris. This
is necessary because normal converter flushing proce-
dures will not remove all contaminants.
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transmssion has too much fluid, the
geartrain churns up foam and cause the same condi-
tions which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can
interfere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transmission vent where it may be mis-
taken for a leak.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
The transmission has a dipstick to check oil level.
It is located on the right side of the engine. Be sure
to wipe all dirt from dipstick handle before removing.
Fluid level is checked with the engine running at
curb idle speed, the transmission in NEUTRAL and
the transmission fluid at normal operating tempera-
ture.The engine should be running at idle
speed for at least one minute, with the vehicle
on level ground.
The transmission fluid level can be checked two
ways.
PROCEDURE ONE
(1) Transmission fluid must be at normal operat-
ing temperature for accurate fluid level check. Drive
vehicle if necessary to bring fluid temperature up to
normal hot operating temperature of 82ÉC (180ÉF).
(2) Position vehicle on level surface.
(3) Start and run engine at curb idle speed.
(4) Apply parking brakes.
(5) Shift transmission momentarily into all gear
ranges. Then shift transmission back to NEUTRAL.
(6) Clean top of filler tube and dipstick to keep
dirt from entering tube.
(7) Remove dipstick (Fig. 87) and check fluid level
as follows:
(a) Correct acceptable level is in crosshatch area.
(b) Correct maximum level is to MAX arrow
mark.
(c) Incorrect level is at or below MIN line.
(d) If fluid is low, add only enough MopartAT F
+4, type 9602, to restore correct level. Do not over-
fill.
21 - 70 AUTOMATIC TRANSMISSION - 42REWJ
FLUID AND FILTER (Continued)