2002 JEEP GRAND CHEROKEE Parking

PARK POWERFLOW
As the engine is running and the crankshaft is
rotating, the flexplate and torque converter, which
are also bolted to it, are all rotating in a clockwise
direction as viewed from the front of the engine. The
notched hub of the torque converter is connected to
the oil pump's internal gear, supplying the transmis-
sion with oil pressure. As the converter turns, it
turns the input shaft in a clockwise direction. As the
input shaft is rotating, the front clutch hub-rear
clutch retainer and all their associated parts are also
rotating, all being directly connected to the input
shaft. The power flow from the engine through the
front clutch hub and rear clutch retainer stops at the
rear clutch retainer. Therefore, no power flow to the
output shaft occurs because no clutches are applied.
The only mechanism in use at this time is the park-
ing sprag (Fig. 3), which locks the parking gear on
the output shaft to the transmission case.
NEUTRAL POWERFLOW
With the gear selector in the NEUTRAL position
(Fig. 4), the power flow of the transmission is essen-
tially the same as in the park position. The only
operational difference is that the parking sprag has
been disengaged, unlocking the output shaft from the
transmission case and allowing it to move freely.
Fig. 3 Park Powerflow
1 - LEVER ENGAGED FOR PARK
2 - PARK SPRAG
3 - OUTPUT SHAFT
Fig. 4 Neutral Powerflow
1 - PAWL DISENGAGED FOR NEUTRAL
2 - PARK SPRAG
3 - OUTPUT SHAFT
4 - CAM
5-PAWL
21 - 6 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (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)

PROCEDURE TWO
(1) Start engine and apply parking brake.
(2) Shift the transmission into DRIVE for approxi-
mately 2 seconds.
(3) Shift the transmission into REVERSE for
approximately 2 seconds.
(4) Shift the transmission into PARK.
(5) Hook up DRBtscan tool and select engine.
(6) Select sensors.
(7) Read the transmission temperature value.
(8) Compare the fluid temperature value with the
figure. (Fig. 88)
(9) Adjust transmission fluid level shown on the
dipstick according to the figure.NOTE: After adding any fluid to the transmission,
wait a minimum of 2 minutes for the oil to fully
drain from the fill tube into the transmission before
rechecking the fluid level.
(10) Check transmission for leaks.
STANDARD PROCEDURE - FLUID AND FILTER
REPLACEMENT
For proper service intervals (Refer to LUBRICA-
TION & MAINTENANCE/MAINTENANCE SCHED-
ULES - DESCRIPTION). The service fluid fill after a
filter change is approximately 3.8 liters (4.0 quarts).
REMOVAL
(1) Hoist and support vehicle on safety stands.
(2) Place a large diameter shallow drain pan
beneath the transmission pan.
(3) Remove bolts holding front and sides of pan to
transmission (Fig. 89).
(4) Loosen bolts holding rear of pan to transmis-
sion.
(5) Slowly separate front of pan and gasket away
from transmission allowing the fluid to drain into
drain pan.
(6) Hold up pan and remove remaining bolt hold-
ing pan to transmission.
Fig. 88 42/44RE Fluid Fill Graph
Fig. 87 Dipstick Fluid Level Marks - Typical
1 - DIPSTICK
2 - MAXIMUM CORRECT FLUID LEVEL
3 - ACCEPTABLE FLUID LEVEL
WJAUTOMATIC TRANSMISSION - 42RE 21 - 71
FLUID AND FILTER (Continued)

(7) While holding pan level, lower pan and gasket
away from transmission.
(8) Pour remaining fluid in pan into drain pan.
(9) Remove screws holding filter to valve body
(Fig. 90).
(10) Separate filter from valve body and pour fluid
in filter into drain pan.
(11) Dispose of used trans fluid and filter properly.
INSTALLATION
(1) Position a new transmission oil filter onto the
valve body.
(2) Install the screws to hold the filter to the valve
body. Tighten the screws to 4 N´m (35 in.lbs.).
(3) Clean the gasket surfaces of the transmission
oil pan and transmission pan rail.NOTE: The transmission pan oil gasket is reusable.
Inspect the sealing surfaces of the gasket. If the
sealing ribs on both surfaces appear to be in good
condition, clean the gasket of any foreign material
and reinstall.
(4) Position the oil pan gasket onto the oil pan.
(5) Position the oil pan and gasket onto the trans-
mission and install several bolts to hold the pan and
gasket to the transmission.
(6) Install the remainder of the oil pan bolts.
Tighten the bolts to 13.6 N´m (125 in.lbs.).
(7) Lower vehicle and fill transmission. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC/
FLUID - STANDARD PROCEDURE)
STANDARD PROCEDURE - TRANSMISSION
FILL
To avoid overfilling transmission after a fluid
change or overhaul, perform the following procedure:
(1) Remove dipstick and insert clean funnel in
transmission fill tube.
(2) Add following initial quantity of MopartAT F
+4, type 9602, to transmission:
(a) If only fluid and filter were changed, add3
pints (1-1/2 quarts)of ATF +4 to transmission.
(b) If transmission was completely overhauled,
torque converter was replaced or drained, and
cooler was flushed, add12 pints (6 quarts)of ATF
+4 to transmission.
(3) Apply parking brakes.
(4)
Start and run engine at normal curb idle speed.
(5) Apply service brakes, shift transmission
through all gear ranges then back to NEUTRAL, set
parking brake, and leave engine running at curb idle
speed.
(6) Remove funnel, insert dipstick and check fluid
level. If level is low,add fluid to bring level to
MIN mark on dipstick.Check to see if the oil level
is equal on both sides of the dipstick. If one side is
noticably higher than the other, the dipstick has
picked up some oil from the dipstick tube. Allow the
oil to drain down the dipstick tube and re-check.
(7) Drive vehicle until transmission fluid is at nor-
mal operating temperature.
(8) With the engine running at curb idle speed, the
gear selector in NEUTRAL, and the parking brake
applied, check the transmission fluid level.
CAUTION: Do not overfill transmission, fluid foam-
ing and shifting problems can result.
(9) Add fluid to bring level up to MAX arrow
mark.
When fluid level is correct, shut engine off, release
park brake, remove funnel, and install dipstick in fill
tube.
Fig. 89 Transmission Pan
1 - TRANSMISSION
2 - GASKET
3-PAN
Fig. 90 Transmission Filter
1 - TRANSMISSION
2 - FILTER
21 - 72 AUTOMATIC TRANSMISSION - 42REWJ
FLUID AND FILTER (Continued)

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 inter-
fere with normal valve, clutch, and accumulator opera-
tion. Foaming can also result in fluid escaping from the
transmission vent where it may be mistaken 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.
The torque converter fills in both the P (PARK)
and N (NEUTRAL) positions. Place the selector lever
in P (PARK) to be sure that the fluid level check is
accurate.The engine should be running at idle
speed for at least one minute, with the vehicle
on level ground.At normal operating temperature(approximately 82 C. or 180 F.), the fluid level is cor-
rect if it is in the HOT region (cross-hatched area) on
the oil level indicator. The fluid level will be approx-
imately at the upper COLD hole of the dipstick at
70É F fluid temperature.
NOTE: Engine and Transmission should be at nor-
mal operating temperature before performing this
procedure.
(1) Start engine and apply parking brake.
(2) Shift the transmission into DRIVE for approxi-
mately 2 seconds.
(3) Shift the transmission into REVERSE for
approximately 2 seconds.
(4) Shift the transmission into PARK.
(5)
Hook up DRBtscan tool and select transmission.
(6) Select sensors.
(7) Read the transmission temperature value.
(8) Compare the fluid temperature value with the
chart. (Fig. 59)
(9) Adjust transmission fluid level shown on the
dipstick according to the chart.
NOTE: After adding any fluid to the transmission,
wait a minimum of 2 minutes for the oil to fully
drain from the fill tube into the transmission before
rechecking the fluid level.
(10) Check transmission for leaks.
Fig. 59 Transmission Fluid Temperature Chart
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 229
FLUID AND FILTER (Continued)

(2) Apply silicone lubricant to a cloth and wipe it
on door seals to avoid over-spray that can soil pas-
senger's clothing.
(3) Before applying lubricant, the component
should be wiped clean. After lubrication, any excess
lubricant should be removed.
(4) The hood latch, latch release mechanism, latch
striker, and safety latch should be lubricated period-
ically.
(5) The door lock cylinders should be lubricated
twice each year (preferably autumn and spring).
(a) Spray a small amount of lock cylinder lubri-
cant directly into the lock cylinder.
(b) Apply a small amount to the key and insert
it into the lock cylinder.
(c) Rotate it to the locked position and then back
to the unlocked position several times.(d) Remove the key. Wipe the lubricant from it
with a clean cloth to avoid soiling of clothing.
STANDARD PROCEDURE - DRILLING AND
WELDING
When holes must be drilled or punched in an inner
body panel, verify depth of space to the outer body
panel, electrical wiring, or other components. Dam-
age to vehicle can result.
Do not weld exterior panels unless combustible
material on the interior of vehicle is removed from
the repair area. Fire or hazardous conditions, can
result.
Always have a fire extinguisher ready for use when
welding.
SPECIFICATIONS
BODY LUBRICANTS
COMPONENT SERVICE INTERVAL LUBRICANT
Door Hinges As RequiredMulti-Purpose Grease NLGI GC-LB
(Water Resistant) (1)
Door Latches As RequiredMulti-Purpose Grease NLGI GC-LB
(Water Resistant) (1)
Hood Latch, Release Mechanism and
Safety LatchAs Required
(When Performing Other
Underhood Service)Multi-Purpose Grease NLGI GC-LB 2
EP (2)
Hood Hinges As Required Engine Oil
Seat Track and Release Mechanism As RequiredMulti-Purpose Grease NLGI GC-LB 2
EP (2)
Liftgate Hinge As RequiredMulti-Purpose Grease NLGI GC-LB 2
EP (2)
Liftgate Support Arms As Required Engine Oil
Liftgate Latches As Required White Spray Lubricant (3)
Liftgate Release Handle (Pivot and Slide
Contact Surfaces)As RequiredMulti-Purpose Grease NLGI GC-LB 2
EP (2)
Window System Components As Required White Spray Lubricant (3)
Lock Cylinders Twice a Year Lock-Cylinder Lubricant (4)
Parking Brake Mechanism As RequiredMulti-Purpose Grease NLGI GC-LB 2
EP (1)
1 = Mopar Wheel Bearing Grease (High
Temp)
2 = Mopar Multi-Mileage Lubricant
3 = Mopar Spray White Lube
4 = Mopar Lock Cylinder Lubricant
WJBODY 23 - 3
BODY (Continued)

FLOOR CONSOLE
REMOVAL
CAUTION: The ACM should be depowered by dis-
connecting the negative battery cable in any opera-
tion requiring the key to be turned ªONº, while
working in the console area. E.G. console, carpet,
or seat removal or installation; shifter linkage
adjustment or replacement; parking brake cable
replacement or adjustment. Failure to take proper
precautions could result in accidental airbag
deployment and possible personal injury.
(1) Set park brake.
(2) Place transmission shift lever and transfer case
lever in full rearward position.
(3) Remove mat from front bin and remove screws
attaching front of console to floor (Fig. 8).
(4) Remove screws attaching rear bin to console.
(5) Remove rear bin.
(6) Pull rear passenger cupholder outward to
access screws.
(7)
Remove screws attaching rear of console to floor.
(8) Lift the console upward and rearward.
(9) Remove console from vehicle.
INSTALLATION
CAUTION: The ACM should be depowered by dis-
connecting the negative battery cable in any opera-
tion requiring the key to be turned ªONº, while
working in the console area. E.G. console, carpet,
or seat removal or installation; shifter linkage
adjustment or replacement; parking brake cable
replacement or adjustment. Failure to take proper
precautions could result in accidental airbag
deployment and possible personal injury.
(1) Position console in vehicle. Ensure rear passen-
ger HEVAC duct is engaged.
(2) Install screws attaching rear of console to floor.
(3) Position rear bin in console.
(4) Install screws attaching rear bin to console.
(5) Install screws attaching front of console to floor
and place front bin mat in front bin.
(6) Return transmission shift lever and transfer
case lever to original position.
(7) Release park brake.
Fig. 8 Floor Console
1 - REAR BIN
2 - CONSOLE LID
3 - SHIFTER CONSOLE
4 - BRACKET5 - PARKING BRAKE
6 - FRONT PIN
7-MAT
23 - 76 INTERIORWJ