lock JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

OPERATION
The converter impeller (Fig. 115) (driving member),
which is integral to the converter housing and bolted
to the engine drive plate, rotates at engine speed.
The converter turbine (driven member), which reacts
from fluid pressure generated by the impeller, rotates
and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into the
turbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
ing the trailing edges of the turbine's blades it con-
tinues in a ªhinderingº direction back toward the
impeller. If the fluid is not redirected before it strikes
the impeller, it will strike the impeller in such a
direction that it would tend to slow it down.
STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 116).
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-
clockwise direction. When this happens the over-run-ning clutch of the stator locks and holds the stator
from rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.4:1. As the turbine
begins to match the speed of the impeller, the fluid
that was hitting the stator in such as way as to
cause it to lock-up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston and friction
material to the front cover, a total converter engage-
ment can be obtained. The result of this engagement
is a direct 1:1 mechanical link between the engine
and the transmission.
The clutch can be engaged in second, third, fourth,
and fifth gear ranges depending on overdrive control
switch position. If the overdrive control switch is in
the normal ON position, the clutch will engage after
the shift to fourth gear, and above approximately 72
km/h (45 mph). If the control switch is in the OFF
Fig. 115 Torque Converter Fluid Operation - Typical
1 - APPLY PRESSURE 3 - RELEASE PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD 4 - THE PISTON MOVES SLIGHTLY REARWARD
21 - 268 AUTOMATIC TRANSMISSION - 545RFEWJ
TORQUE CONVERTER (Continued)

position, the clutch will engage after the shift to
third gear, at approximately 56 km/h (35 mph) at
light throttle.
The TCM controls the torque converter by way of
internal logic software. The programming of the soft-
ware provides the TCM with control over the L/R-CC
Solenoid. There are four output logic states that can
be applied as follows:
²No EMCC
²Partial EMCC
²Full EMCC
²Gradual-to-no EMCC
NO EMCC
Under No EMCC conditions, the L/R Solenoid is
OFF. There are several conditions that can result in
NO EMCC operations. No EMCC can be initiated
due to a fault in the transmission or because the
TCM does not see the need for EMCC under current
driving conditions.
PARTIAL EMCC
Partial EMCC operation modulates the L/R Sole-
noid (duty cycle) to obtain partial torque converter
clutch application. Partial EMCC operation is main-
tained until Full EMCC is called for and actuated.
During Partial EMCC some slip does occur. Partial
EMCC will usually occur at low speeds, low load and
light throttle situations.
FULL EMCC
During Full EMCC operation, the TCM increases
the L/R Solenoid duty cycle to full ON after PartialEMCC control brings the engine speed within the
desired slip range of transmission input speed rela-
tive to engine rpm.
GRADUAL-TO-NO EMCC
This operation is to soften the change from Full or
Partial EMCC to No EMCC. This is done at mid-
throttle by decreasing the L/R Solenoid duty cycle.
REMOVAL
(1) Remove transmission and torque converter
from vehicle.
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive flats for sharp
edges, burrs, scratches, or nicks. Polish the hub and
flats with 320/400 grit paper or crocus cloth if neces-
sary. Verify that the converter hub o-ring is properly
installed and is free from debris. The hub must be
smooth to avoid damaging the pump seal at installa-
tion.
(1) Lubricate oil pump seal lip with transmission
fluid.
(2) Place torque converter in position on transmis-
sion.
CAUTION: Do not damage oil pump seal or con-
verter hub o-ring while inserting torque converter
into the front of the transmission.
(3) Align torque converter to oil pump seal open-
ing.
(4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears.
(6) Check converter seating with a scale and
straightedge (Fig. 117). Surface of converter lugs
should be at least 13 mm (1/2 in.) to rear of straight-
edge when converter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
Fig. 116 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 269
TORQUE CONVERTER (Continued)

REMOVAL
(1) Remove the valve body from the transmission
(Fig. 119).
(2) Remove the screws holding the transmission
solenoid/TRS assembly onto the valve body (Fig. 120).
(3) Separate the transmission solenoid/TRS assem-
bly from the valve body.
INSTALLATION
(1) Place TRS selector plate in the PARK position.
(2) Position the transmission solenoid/TRS assem-
bly onto the valve body. Be sure that both alignment
dowels are fully seated in the valve body and that
the TRS switch contacts are properly positioned in
the selector plate
(3) Install the screws to hold the transmission
solenoid/TRS assembly onto the valve body.
(4) Tighten the solenoid assembly screws adjacent
to the arrows cast into the bottom of the valve body
first. Tighten the screws to 5.7 N´m (50 in.lbs.).
(5) Tighten the remainder of the solenoid assembly
screws to 5.7 N´m (50 in.lbs.).
(6) Install the valve body into the transmission.
TRANSMISSION
TEMPERATURE SENSOR
DESCRIPTION
The transmission temperature sensor is a ther-
mistor that is integral to the Transmission Range
Sensor (TRS).
OPERATION
The transmission temperature sensor is used by
the TCM to sense the temperature of the fluid in the
sump. Since fluid temperature can affect transmis-
sion shift quality and convertor lock up, the TCM
requires this information to determine which shift
schedule to operate in.
Calculated Temperature
A failure in the temperature sensor or circuit will
result in calculated temperature being substituted for
actual temperature. Calculated temperature is a pre-
dicted fluid temperature which is calculated from a
combination of inputs:
²Battery (ambient) temperature
²Engine coolant temperature
²In-gear run time since start-up
Fig. 119 Valve Body Bolts
1 - VALVE BODY TO CASE BOLT (6)
Fig. 120 Ttransmission Solenoid/TRS Assembly
Screws
1 - SOLENOID PACK BOLTS (15)
21 - 272 AUTOMATIC TRANSMISSION - 545RFEWJ
TRANSMISSION SOLENOID/TRS ASSEMBLY (Continued)

(2) Remove seal plug from low range fork lockpin
access hole. Then move shift sector to align low range
fork lockpin with access hole.
(3) Remove range fork lockpin with size number
one easy-out tool as follows:
(a) Insert easy-out tool through access hole in
side of transfer case and into lock-pin.
(b) Tap easy-out tool into lock-pin with hammer
until tool is securely engaged into the lock-pin.
(c) Install a t-handle, such as from a tap and die
set, onto the easy-out tool.
(d) Securely tighten the t-handle onto the tool.
(e) In one motion, pull upward and turn the
t-handle counter-clockwise to remove the lock-pin.
(4) Remove shift rail by pulling it straight up and
out of fork (Fig. 27).
(5) Remove mode fork and mainshaft as assembly
(Fig. 28).
(6) Remove mode shift sleeve and mode fork
assembly from mainshaft (Fig. 29). Note position of
mode sleeve in fork and remove sleeve.
Fig. 27 Shift Rail Removal
1 - SHIFT RAIL
2 - MODE FORK
Fig. 28 Mainshaft And Mode Fork Removal
1 - MAINSHAFT ASSEMBLY
2 - MODE FORK
Fig. 29 Separate Mode Fork And Sleeve
1 - MAINSHAFT
2 - MODE SLEEVE
3 - MODE FORK ASSEMBLY
21 - 288 TRANSFER CASE - NV242WJ
TRANSFER CASE - NV242 (Continued)

INSPECTION
MAINSHAFT/SPROCKET/HUB
Inspect the splines on the hub and shaft and the
teeth on the sprocket. Minor nicks and scratches can
be smoothed with an oilstone. However, replace any
part that is damaged.
Check the contact surfaces in the sprocket bore
and on the mainshaft. Minor nicks and scratches can
be smoothed with 320-400 grit emery cloth but do not
try to salvage the shaft if nicks or wear is severe.
INPUT GEAR AND PLANETARY CARRIER
Check the teeth on the gear (Fig. 46). Minor nicks
can be dressed off with an oilstone but replace the
gear if any teeth are broken, cracked, or chipped. The
bearing surface on the gear can be smoothed with
300-400 grit emery cloth if necessary.
Examine the carrier body and pinion gears for
wear or damage. The carrier will have to be replaced
as an assembly if the body, pinion pins, or pinion
gears are damaged.
Check the lock ring and both thrust washers for
wear or cracks. Replace them if necessary. Also
replace the lock retaining ring if bent, distorted, or
broken.
Fig. 46 Input Gear And Carrier Components
1 - PLANETARY CARRIER 4 - CARRIER LOCK RING
2 - REAR THRUST WASHER 5 - CARRIER LOCK RETAINING RING
3 - FRONT THRUST WASHER 6 - INPUT GEAR
Fig. 45 Mainshaft And Sprocket Gear Removal
1 - MAINSHAFT GEAR
2 - SPROCKET GEAR
3 - BOTTOM CASE
WJTRANSFER CASE - NV242 21 - 293
TRANSFER CASE - NV242 (Continued)

REAR OUTPUT SHAFT/YOKE/DRIVE CHAIN
Check condition of the seal contact surfaces of the
yoke slinger (Fig. 49). This surface must be clean and
smooth to ensure proper seal life. Replace the yoke
nut and seal washer as neither part should be
reused.
Inspect the shaft threads, sprocket teeth, and bear-
ing surfaces. Minor nicks on the teeth can be
smoothed with an oilstone. Use 320-400 grit emery to
smooth minor scratches on the shaft bearing sur-
faces. Rough threads on the shaft can be chased if
necessary. Replace the shaft if the threads are dam-
aged, bearing surfaces are scored, or if any sprocket
teeth are cracked or broken.
Examine the drive chain and shaft bearings.
Replace the chain and both sprockets if the chain is
stretched, distorted, or if any of the links bind.
Replace the bearings if rough, or noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear condition carefully. The gear
is only serviced as part of the front case. If the gear
is damaged, it will be necessary to replace the gear
and front case as an assembly. Do not attempt to
remove the gear (Fig. 50)
FRONT-REAR CASES AND FRONT RETAINER
Inspect the cases and retainer for wear and dam-
age. Clean the sealing surfaces with a scraper and
3M all purpose cleaner. This will ensure proper
sealer adhesion at assembly. Replace the input
retainer seal; do not reuse it.Check case condition. If leaks were a problem, look
for gouges and severe scoring of case sealing sur-
faces. Also make sure the front case mounting studs
are in good condition.
Check the front case mounting studs and vent
tube. The tube can be secured with LoctiteŸ 271 or
680 if loose. The stud threads can be cleaned up with
a die if necessary. Also check condition of the fill/
drain plug threads in the rear case. The threads can
be repaired with a thread chaser or tap if necessary.
Or the threads can be repaired with HelicoilŸ stain-
less steel inserts if required.
OIL PUMP/OIL PICKUP
Examine the oil pump pickup parts. Replace the
pump if any part appears to be worn or damaged. Do
not disassemble the pump as individual parts are not
available. The pump is only available as a complete
assembly. The pickup screen, hose, and tube are the
only serviceable parts and are available separately.
ASSEMBLY
Lubricate transfer case components with automatic
transmission fluid or petroleum jelly (where indi-
cated) during assembly.
CAUTION: The bearing bores in various transfer
case components contain oil feed holes. Make sure
replacement bearings do not block the holes.
Fig. 49 Seal Contact Surface Of Yoke Slinger
1 - FRONT SLINGER (PART OF YOKE)
2 - SEAL CONTACT SURFACE MUST BE CLEAN AND SMOOTH
Fig. 50 Low Range Annulus Gear
1 - FRONT CASE
2 - LOW RANGE ANNULUS GEAR
WJTRANSFER CASE - NV242 21 - 295
TRANSFER CASE - NV242 (Continued)

(18) Install shift rail (Fig. 81). Be sure rail is
seated in both shift forks.
(19) Rotate shift sector to align lockpin hole in low
range fork with access hole in case.
(20) Insert an easy-out in range fork lockpin to
hold it securely for installation (Fig. 82). Lockpin is
slightly tapered on one end. Insert tapered end into
fork and rail.
(21) Insert lockpin through access hole and into
shift fork (Fig. 82). Then remove easy-out and seat
the pin with pin punch.
(22) Install plug in lockpin access hole.
(23) Install detent plunger, detent spring and
detent plug in case (Fig. 83).
Fig. 81 Shift Rail Installation
1 - SHIFT RAIL
2 - MODE FORK
Fig. 82 Installing Low Range Fork Lockpin
1 - LOW RANGE FORK LOCK PIN
2 - ACCESS HOLE
3 - EASY-OUT
Fig. 83 Detent Pin, Spring And Plug Installation
1 - PLUNGER
2 - O-RING
3 - PLUG
4 - SPRING
21 - 304 TRANSFER CASE - NV242WJ
TRANSFER CASE - NV242 (Continued)

CONDITION POSSIBLE CAUSE CORRECTION
NOISY INÐOR JUMPS OUT OF
4WD LOW RANGE1. Transfer case not completely
engaged in 4WD LOW (possibly
from shift to 4L while rolling)1. Stop vehicle, shift transfer case
to neutral, then shift back to 4WD
LOW
2. Shift linkage loose, binding, or is
misadjusted2. Tighten, lubricate, or repair
linkage as necessary. Adjust linkage
if necessary
3. Range fork cracked, inserts
worn, or fork is binding on shift rail3. Disassemble unit and repair as
necessary
4. Annulus gear or lockplate worn
or damaged4. Disassemble unit and repair as
necessary
LUBRICANT LEAKING FROM
OUTPUT SHAFT SEALS OR FROM
VENT1. Transfer case over filled 1. Drain to correct level
2. Vent closed or restricted 2. Clear or replace vent if necessary
3. Output shaft seals damaged or
installed correctly3. Replace seals. Be sure seal lip
faces interior of case when installed.
Also be sure yoke seal surfaces are
not scored or nicked. Remove
scores and nicks with fine
sandpaper or replace yoke(s) if
necessary.
REMOVAL
(1) Shift transfer case into NEUTRAL.
(2) Raise vehicle.
(3) Remove transfer case drain plug and drain
transfer case lubricant.
(4) Mark front and rear propeller shaft yokes for
alignment reference.
(5) Support transmission with jack stand.
(6) Remove rear crossmember and skid plate, if
equipped (Fig. 4).
(7) Disconnect front propeller shaft from transfer
case at companion flange. Remove rear propeller
shaft from vehicle. (Refer to 3 - DIFFERENTIAL &
DRIVELINE/PROPELLER SHAFT/PROPELLER
SHAFT - REMOVAL)
CAUTION: Do not allow propshafts to hang at
attached end. Damage to joint can result.
(8) Disconnect transfer case cable from range
lever.
(9) Disconnect transfer case vent hose (Fig. 5).
(10) Support transfer case with transmission jack.
(11) Secure transfer case to jack with chains.
(12) Remove nuts attaching transfer case to trans-
mission.
(13) Pull transfer case and jack rearward to disen-
gage transfer case (Fig. 5).
(14) Remove transfer case from under vehicle.
DISASSEMBLY
Position transfer case on shallow drain pan.
Remove drain plug and drain lubricant remaining in
case.
Fig. 4 Crossmember Removal
1 - CROSSMEMBER
2 - REAR TRANSMISSION MOUNT
WJTRANSFER CASE - NV247 21 - 317
TRANSFER CASE - NV247 (Continued)

(7) Remove range clutch sleeve, blockout spring,
locking clutch, and locking clutch spring from main-
shaft (Fig. 20).
(8) Remove shift sector. Rotate and tilt sector as
needed to remove it (Fig. 21).
(9) Remove shift sector bushing and O-ring (Fig.
22).
INPUT GEAR/LOW RANGE ASSEMBLY
(1) Turn front case on side so front bearing
retainer is accessible.
(2) Remove front bearing retainer bolts (Fig. 23).
(3) Remove front bearing retainer as follows:(a) Loosen retainer with flat blade screwdriver
to break sealer bead.To avoid damaging case
and retainer, position screwdriver blade only
in slots provided in retainer (Fig. 24).
(b) Then remove retainer from case and gear.
Fig. 20 Range Clutch Sleeve, Blockout Spring,
Locking Clutch and Spring
1 - LOCKING CLUTCH SPRING
2 - BLOCKOUT SPRING
3 - SNAP-RING
4 - RANGE CLUTCH SLEEVE
5 - LOCKING CLUTCH
6 - DRIVE SPROCKET HUB
Fig. 21 Shift Sector Removal
1 - SHIFT SECTOR
Fig. 22 Sector Bushing And O-Ring Removal
1 - SHIFT SECTOR BUSHING
2 - O-RING
Fig. 23 Front Bearing Retainer Bolt Removal
1 - FRONT BEARING RETAINER
21 - 322 TRANSFER CASE - NV247WJ
TRANSFER CASE - NV247 (Continued)

ASSEMBLY
Lubricate transfer case components with Mopart
Transfer Case Lubricant or petroleum jelly (where
indicated) during assembly.
CAUTION: The bearing bores in various transfer
case components contain oil feed holes. Make sure
replacement bearings do not block the holes.
BEARINGS AND SEALS
(1) Remove front output shaft seal from front case
with pry tool (Fig. 33).
(2) Remove snap-ring that retains front output
shaft bearing in front case (Fig. 34).
(3) Using tool 6953, remove bearing from front
case (Fig. 35).
(4) Using tool 6953, install new bearing.
(5) Install snap-ring to hold bearing into case.
Fig. 33 Remove Front Output Shaft Seal
1 - OUTPUT SHAFT SEAL
2 - PRYBAR
Fig. 34 Output Shaft Front Bearing Snap-Ring
Removal
1 - FRONT CASE
2 - OUTPUT SHAFT FRONT BEARING
3 - BEARING SNAP-RING
Fig. 35 Remove Output Shaft Front Bearing
1 - HANDLE C-4171
2 - REMOVER/INSTALLER 6953
21 - 326 TRANSFER CASE - NV247WJ
TRANSFER CASE - NV247 (Continued)