2002 JEEP GRAND CHEROKEE Air ah

NOTE: The 545RFE utilizes closed loop control of
pump line pressure. The pressure readings may
therefore vary greatly but should always follow line
pressure.
Some common pressures that can be measured to
evaluate pump and clutch performance are the
upshift/downshift pressures and the garage shift
pressures. The upshift/downshift pressure for all
shifts except the 4-5 shift is 120 psi. The upshift
pressure for the 4-5 shift is 130 psi. The garage shift
pressure when performing a N-R shift is 220 psi. The
garage shift pressure for the R-N and N-1 shifts is
120 psi.
DIAGNOSIS AND TESTING - AIR CHECKING
TRANSMISSION CLUTCH OPERATION
Air-pressure testing can be used to check transmis-
sion clutch operation. The test can be conducted with
the transmission either in the vehicle or on the work
bench, as a final check.
Air-pressure testing requires that the oil pan and
valve body be removed from the transmission. The
clutch apply passages are shown (Fig. 6).
NOTE: The air supply which is used must be free of
moisture and dirt. Use a pressure of 30 psi to test
clutch operation.Apply air pressure at each port. If the clutch is
functioning, a soft thump will be heard as the clutch
is applied. The clutch application can also be felt by
touching the appropriate element while applying air
pressure. As the air pressure is released, the clutch
should also release.
DIAGNOSIS AND TESTING - CONVERTER
HOUSING FLUID LEAK
When diagnosing converter housing fluid leaks,
two items must be established before repair.
(1) Verify that a leak condition actually exists.
(2) Determined the true source of the leak.
Some suspected converter housing fluid leaks may
not be leaks at all. They may only be the result of
residual fluid in the converter housing, or excess
fluid spilled during factory fill or fill after repair.
Converter housing leaks have several potential
sources. Through careful observation, a leak source
can be identified before removing the transmission
for repair. Torque converter seal leaks tend to move
along the drive hub and onto the rear of the con-
verter. Pump cover seal tend to run down the cover
and the inside surface of the bellhousing.
Some leaks, or suspected leaks, may be particu-
larly difficult to locate. If necessary, a Mopart
approved dye may be used to locate a leak.
Fig. 5 Valve Body Pressure Tap Adapter 8258-A
1 - 545RFE TRANSMISSION
2 - TOOL 8258-A
Fig. 6 Air Pressure Test Passages
1 - LOW REVERSE CLUTCH
2 - 4TH CLUTCH
3 - 2ND CLUTCH
4 - OVERDRIVE CLUTCH
5 - UNDERDRIVE CLUTCH
6 - REVERSE CLUTCH
21 - 182 AUTOMATIC TRANSMISSION - 545RFEWJ
AUTOMATIC TRANSMISSION - 545RFE (Continued)

TORQUE CONVERTER LEAK POINTS
Possible sources of converter leaks are:
(1) Leaks at the weld joint around the outside
diameter weld (Fig. 7).
(2) Leaks at the converter hub weld (Fig. 7).
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, or
equivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
REMOVAL
CAUTION: The transmission and torque converter
must be removed as an assembly to avoid compo-
nent damage. The converter driveplate, converter
hub o-ring, or oil seal can be damaged if the con-
verter is left attached to the driveplate during
removal. Be sure to remove the transmission and
converter as an assembly.
(1) Disconnect the negative battery cable.
(2) Raise and support the vehicle
(3) Mark propeller shaft and axle yokes for assem-
bly alignment.
(4) Remove the rear propeller shaft
(5) Remove the front propeller shaft.
(6) Remove the engine to transmission collar (Fig.
8).
(7) Remove the exhaust support bracket from the
rear of the transmission.
(8) Disconnect and lower or remove any necessary
exhaust components.
(9) Remove the starter motor.
(10) Rotate crankshaft in clockwise direction until
converter bolts are accessible. Then remove bolts one
at a time. Rotate crankshaft with socket wrench on
dampener bolt.
(11) Disconnect wires from solenoid and pressure
switch assembly, input and output speed sensors, and
line pressure sensor.
Fig. 7 Torque Converter Assembly
1 - TURBINE ASSEMBLY
2-STATOR
3 - CONVERTER HUB
4 - O-RING
5 - IMPELLER ASSEMBLY
6 - CONVERTER CLUTCH PISTON
7 - TURBINE HUB
Fig. 8 Transmission Collar
1 - ENGINE
2 - ENGINE TO TRANSMISSION COLLAR
3 - TRANSMISSION
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 183
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(48) Remove the manual selector shaft seal.
(49) Remove the dipstick tube seal.
CLEANING
The use of crocus cloth is permissible where neces-
sary, providing it is used carefully. When used on
shafts, or valves, use extreme care to avoid rounding
off sharp edges. Sharp edges are vital as they pre-
vent foreign matter from getting between the valve
and valve bore.
Do not reuse oil seals, gaskets, seal rings, or
O-rings during overhaul. Replace these parts as a
matter of course. Also do not reuse snap rings or
E-clips that are bent or distorted. Replace these parts
as well.
Lubricate transmission parts with MopartATF +4,
Type 9602, transmission fluid during overhaul and
assembly. Use petroleum jelly, MopartDoor Ease, or
Ru-Glyde to prelubricate seals, O-rings, and thrust
washers. Petroleum jelly can also be used to hold
parts in place during reassembly.Clean the case in a solvent tank. Flush the case
bores and fluid passages thoroughly with solvent.
Dry the case and all fluid passages with compressed
air. Be sure all solvent is removed from the case and
that all fluid passages are clear.
NOTE: Do not use shop towels or rags to dry the
case (or any other transmission component) unless
they are made from lint-free materials. Lint will stick
to case surfaces and transmission components and
circulate throughout the transmission after assem-
bly. A sufficient quantity of lint can block fluid pas-
sages and interfere with valve body operation.
INSPECTION
Inspect the case for cracks, porous spots, worn
bores, or damaged threads. Damaged threads can be
repaired with Helicoil thread inserts. However, the
case will have to be replaced if it exhibits any type of
damage or wear.
ASSEMBLY
(1) Clean and inspect all components. Replace any
components which show evidence of excessive wear
or scoring.
(2) Install the cooler filter bypass valve.
(3) Torque the bypass valve to specification. The
valve uses a tapered pipe thread and excessive
torque can damage the transmission case. Tighten
the cooler filter bypass valve to 4.5 N´m (40 in.lbs.).
(4) Install a new selector shaft seal using Seal
Installer 8253 (Fig. 31).
Fig. 30 Manual Shaft/Park Lock Components
1 - GUIDE
2 - SNAP-RING
3 - SHAFT
4 - SPRING
5 - PARK PAWL
6 - MANUAL SHAFT/LEVER
7 - PARK ROD
Fig. 31 Install Selector Shaft
1 - SEAL
2 - TOOL 8253
21 - 190 AUTOMATIC TRANSMISSION - 545RFEWJ
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(15) Using a feeler gauge through the opening in
the rear of the transmission case, measure the 2C
clutch pack clearance between the 2C reaction plate
and the transmission case at four different points.
The average of these measurements is the 2C clutch
pack clearance. The correct clutch clearance is 0.455-
1.335 mm (0.018-0.053 in.). The reaction plate is not
selective. If the clutch pack clearance is not within
specification, the reaction plate, all the friction discs,
and steels must be replaced.
(16) Remove the 4C retainer/bulkhead and all of
the 2C clutch components from the transmission
case.
(17) Install the low/reverse clutch assembly (Fig.
35). Make sure that the oil feed hole points toward
the valve body area and that the bleed orifice is
aligned with the notch in the rear of the transmis-
sion case.
(18) Install the snap-ring to hold the low/reverse
clutch retainer into the transmission case (Fig. 35).
The snap-ring is tapered and must be installed with
the tapered side forward. Once installed, verify that
the snap-ring is fully seated in the snap-ring groove.
(19) Air check the low/reverse clutch and verify
correct overrunning clutch operation.
(20) Install the number 12 bearing over the output
shaft and against the rear planetary gear set. The
flat side of the bearing goes toward the planetary
gearset and the raised tabs on the inner race should
face the rear of the transmission.(21) Install the reverse/input planetary assembly
through the low/reverse clutch assembly (Fig. 36).
(22) Install the park sprag onto the output shaft
(Fig. 37).
(23) Install the snap-ring to hold the park sprag
onto the output shaft (Fig. 38).
Fig. 35 Install Low/Reverse Clutch Retainer
1 - LOW/REVERSE OVERRUNNING CLUTCH ASSEMBLY
2 - SNAP-RING
Fig. 36 Install Input/Reverse Planetary Assembly
1 - INPUT/REVERSE PLANETARY ASSEMBLY
2 - BEARING NUMBER 9
3 - BEARING NUMBER 12
Fig. 37 Install Park Sprag Gear
1 - PARK SPRAG GEAR
21 - 192 AUTOMATIC TRANSMISSION - 545RFEWJ
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(24) Install the 2C reaction plate into the trans-
mission case (Fig. 39). The reaction plate is direc-
tional. The plate must be installed with the flat side
toward the front of the transmission.
(25) Install the 2C clutch pack into the transmis-
sion case (Fig. 39).(26) Install the number 8 bearing inside the reac-
tion carrier with the outer race against the reaction
planetary carrier.
(27) Install the reaction planetary gear set and the
number 9 bearing, with the inner race against the
reaction planetary carrier, into the transmission case
(Fig. 40).
(28) Install the flat 2C clutch snap-ring into the
transmission case (Fig. 39).
(29) Install the reaction sun gear into the reaction
planetary gear set.Make surethe small shoulder is
facing the front of the transmission (Fig. 40).
(30) Install the number 7 bearing onto the reaction
sun gear with the inner race against the sun gear
(Fig. 40).
(31) Install the output shaft selective thrust plate
onto the reaction annulus with the oil grooves facing
the annulus gear and the tabs and notches aligned as
shown in (Fig. 41).
(32) Install the number 6 bearing against the out-
put shaft selective thrust plate with the flat side
against the thrust plate (Fig. 40) and the raised tabs
on the inner race facing the front of the transmis-
sion.
(33) Install the reaction annulus into the reaction
planetary gear set (Fig. 40).
(34) Install the 4C retainer/bulkhead into the
transmission case. Make sure that the oil feed holes
are pointing toward the valve body area. Rotate the
reaction annulus during the installation of the 4C
retainer/bulkhead to ease installation.
(35) Install the 4C retainer/bulkhead tapered
snap-ring into the transmission case (Fig. 42) with
the taper toward the front of the case. Make sure
that the open ends of the snap-ring are located in the
case opening toward the valve body area.
(36) Air check the 2C and 4C clutch operation.
Fig. 38 Install Park Sprag Snap-Ring
1 - SNAP-RING
Fig. 39 Install 2C Clutch Pack
1 - SNAP-RING
2 - PLATE
3 - DISC
4 - REACTION PLATE
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 193
AUTOMATIC TRANSMISSION - 545RFE (Continued)

4C RETAINER/BULKHEAD
DISASSEMBLY
(1) Remove the 2C piston belleville spring snap-
ring from the 4C retainer /bulkhead (Fig. 53).
(2) Remove the 2C piston Belleville spring from
the retainer/bulkhead (Fig. 53).
(3) Remove the 2C piston from the retainer/bulk-
head. Use 20 psi of air pressure to remove the piston
if necessary.
(4) Remove the 4C clutch snap-ring from the
retainer/bulkhead (Fig. 53).
(5) Remove the 4C clutch pack from the retainer/
bulkhead (Fig. 53).
(6) Using Spring Compressor 8250 and a suitable
shop press, compress the 4C piston return spring and
remove the snap-ring (Fig. 53).(7) Remove the 4C piston return spring and piston
from the retainer/bulkhead (Fig. 53). Use 20 psi of
air pressure to remove the piston if necessary.ASSEMBLY
(1) Clean and inspect all components. Replace any
components which show evidence of excessive wear
or scoring.
(2) Install new seals on the 2C and 4C pistons
(Fig. 53).
(3) Lubricate all seals with MopartATF +4, type
9602 prior to installation.
(4) Install the 4C piston into the 4C retainer/bulk-
head (Fig. 53).
(5) Position the 4C piston return spring onto the
4C piston.
Fig. 53 4C Retainer/Bulkhead Components
1 - SEAL 8 - REACTION PLATE
2 - 2C PISTON 9 - SNAP-RING
3 - PLATE 10 - RETURN SPRING
4 - DISC 11 - SEAL
5 - 2C BELLEVILLE SPRING 12 - 4C PISTON
6 - SNAP-RING 13 - 4C RETAINER/BULKHEAD
7 - SNAP-RING (SELECT)
21 - 224 AUTOMATIC TRANSMISSION - 545RFEWJ

(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.
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has three primary causes.
(1) Internal clutch slippage, usually caused by low
line pressure, inadequate clutch apply pressure, or
clutch seal failure.
(2) 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.(3) 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 cool-
ers as well. The torque converter should also be
replaced whenever a failure generates sludge and
debris. This is necessary because normal converter
flushing procedures will not remove all contami-
nants.
21 - 228 AUTOMATIC TRANSMISSION - 545RFEWJ
BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM (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)