3-4 ACCUMULATOR
(1) Lubricate accumulator piston, seals and hous-
ing piston bore with clean transmission fluid (Fig.
306).
(2) Install new seal rings on accumulator piston.
(3) Install piston and spring in housing.
(4) Install end plate on housing.
TRANSFER PLATE
(1) Install rear clutch and rear servo check balls in
transfer plate (Fig. 307).
(2) Install filter screen in upper housing separator
plate (Fig. 308).
(3) Align and position upper housing separator
plate on transfer plate (Fig. 309).
(4) Install brace plate (Fig. 309). Tighten brace
attaching screws to 4 N´m (35 in. lbs.) torque.
(5) Install remaining separator plate attaching
screws. Tighten screws to 4 N´m (35 in. lbs.) torque.
Fig. 306 3-4 Accumulator and Housing
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
Fig. 307 Rear Clutch And Rear Servo Check Ball
Locations
1 - REAR CLUTCH CHECK BALL
2 - REAR SERVO CHECK BALL
3 - TRANSFER PLATE
Fig. 308 Separator Plate Filter Screen Installation
1 - UPPER HOUSING SEPARATOR PLATE
2 - FILTER SCREEN
Fig. 309 Brace Plate
1 - BRACE
2 - TRANSFER PLATE
3 - SEPARATOR PLATE
DRAUTOMATIC TRANSMISSION - 48RE 21 - 301
VALVE BODY (Continued)
o-ring is properly installed and is free of any debris.
The hub must be smooth to avoid damaging pump
seal at installation.
(2) If a replacement transmission is being
installed, transfer any components necessary, such as
the manual shift lever and shift cable bracket, from
the original transmission onto the replacement trans-
mission.
(3) Lubricate oil pump seal lip with transmission
fluid.
(4) Align converter and oil pump.(5) Carefully insert converter in oil pump. Then
rotate converter back and forth until fully seated in
pump gears.
(6) Check converter seating with steel scale and
straightedge (Fig. 53). Surface of converter lugs
should be at least 13mm (1/2 in.) to rear of straight-
edge when converter is fully seated.
(7) Temporarily secure converter with C-clamp.
(8) Position transmission on jack and secure it
with chains.
(9) Check condition of converter driveplate.
Replace the plate if cracked, distorted or damaged.
Also be sure transmission dowel pins are seated
in engine block and protrude far enough to
hold transmission in alignment.
(10) Apply a light coating of MopartHigh Temp
Grease to the torque converter hub pocket in the rear
pocket of the engine's crankshaft.
(11) Raise transmission (Fig. 54) and align the
torque converter with the drive plate and transmis-
sion converter housing with the engine block.
(12) Move transmission forward. Then raise, lower
or tilt transmission to align the converter housing
with engine block dowels.
(13) Carefully work transmission forward and over
engine block dowels until converter hub is seated in
crankshaft. Verify that no wires, or the transmission
vent hose, have become trapped between the engine
block and the transmission.
(14) Install two bolts to attach the transmission to
the engine.
(15) Install remaining torque converter housing to
engine bolts. Tighten to 68 N´m (50 ft.lbs.).
Fig. 51 Install Primary Oil and Cooler Filters
1 - PRIMARY OIL FILTER
2 - COOLER RETURN FILTER
3 - COOLER RETURN FILTER BYPASS VALVE
4 - VALVE BODY
Fig. 52 Install Input, Output, and Line Pressure
Sensors
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
Fig. 53 Checking Torque Converter Seating - Typical
1 - SCALE
2 - STRAIGHTEDGE
21 - 334 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)
control switch is in the OFF position, the clutch will
engage after the shift to third gear.
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 Partial
EMCC control brings the engine speed within thedesired 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. 125). 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.
(8) Install the transmission in the vehicle.
Fig. 124 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
21 - 404 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
TORQUE CONVERTER (Continued)
TRANSFER CASE - NV241 GENII
TABLE OF CONTENTS
page page
TRANSFER CASE - NV241 GENII
DESCRIPTION........................415
OPERATION..........................415
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV241 GENII..................416
REMOVAL............................417
DISASSEMBLY........................417
CLEANING...........................426
INSPECTION.........................426
ASSEMBLY...........................428
INSTALLATION........................438
SPECIFICATIONS
TRANSFER CASE - NV241 GENII........438
SPECIAL TOOLS
TRANSFER CASE - NV241/NV243........439
EXTENSION HOUSING BUSHING AND SEAL
REMOVAL............................440INSTALLATION........................440
FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL............................441
FRONT OUTPUT SHAFT SEAL
REMOVAL............................441
INSTALLATION........................442
POSITION SENSOR
DESCRIPTION........................442
OPERATION..........................442
REMOVAL............................443
INSTALLATION........................443
SHIFT LEVER
REMOVAL............................444
INSTALLATION........................445
ADJUSTMENTS
ADJUSTMENT - SHIFT LEVER..........446
TRANSFER CASE - NV241
GENII
DESCRIPTION
The NV241 GENII transfer case is a part-time
transfer case with a low-range gear system. It pro-
vides three operating ranges plus a NEUTRAL posi-
tion. The low range position provides a gear
reduction ratio of 2.72:1 for increased low speed
torque capability.
The gear cases and extension are all of aluminum
(Fig. 1). Drive sprockets and an interconnecting drive
chain are used to transmit engine torque to the front/
rear propeller shafts. The mainshaft, input gear and
front output shaft are supported by ball and needle
bearings.
IDENTIFICATION
An identification tag (Fig. 2) is attached to the rear
case of every transfer case. The tag provides the
transfer case model number, assembly number, serial
number, and low range ratio.
The transfer case serial number also represents
the date of build.
OPERATION
OPERATING RANGE
Transfer case operating ranges are:
²2H (2-wheel drive)²4H (4-wheel drive)
²4LO (4-wheel drive low range)
The 2H range is for use on any road surface at any
time.
The 4H and 4LO ranges are for off road use only.
They are not for use on hard surface roads. The only
exception being when the road surface is covered by
ice and snow.
The low range reduction gear system is operative
in 4LO range only. This range is for extra pulling
Fig. 1 Transfer Case - Front View
1 - TRANSFER CASE
2 - MANUAL LEVER
3 - POSITION SENSOR
DRTRANSFER CASE - NV241 GENII 21 - 415
Condition Possible Cause Correction
Noisy in, or jumps out of, four wheel
drive low range.1) Transfer case not completely
engaged in 4L position.1) With the transmission in
NEUTRAL, or the clutch depressed
in the case of a manual
transmission and the vehicle moving
under 3-4 km/h (2-3 mph), shift the
transfer case to NEUTRAL and then
shift into the 4L position.
2) Shift linkage out of adjustment. 2) Adjust linkage.
3) Shift linkage loose or binding. 3) Tighten, lubricate, or repair
linkage as necessary.
4) Range fork damaged, inserts
worn, or fork is binding on the shift
rail.4) Disassemble unit and repair as
necessary.
5) Low range gear worn or
damaged.5) Disassemble unit and repair as
necessary.
Lubricant leaking from output shaft
seal or vent.1) Transfer case overfilled. 1) Drain lubricant to the correct
level.
2) Vent closed or restricted. 2) Clear or replace vent as
necessary.
3) Output shaft seals damaged or
installed incorrectly.3) Replace seal as necessary.
Check to ensure that another
component, the propeller shaft slip
yoke for example, is not causing
damage to seal.
Abnormal tire wear. 1) Extended operation on hard, dry
surfaces in the 4H position.1) Operate vehicle in the 2H
position on hard, dry surfaces.
REMOVAL
(1) Raise and support vehicle.
(2) Remove skid plate, if equipped. (Refer to 13 -
FRAMES & BUMPERS/FRAME/TRANSFER CASE
SKID PLATE - REMOVAL)
(3) Position drain oil container under transfer
case.
(4) Remove transfer case drain plug and drain
lubricant into container.
(5) Disconnect vent hose and transfer case position
sensor connector.
(6) Disconnect shift rod from grommet in transfer
case shift lever, or from floor shift arm whichever
provides easy access. Use channel lock style pliers to
press rod out of lever grommet.
(7) Support transmission with jack stand.
(8) Mark front and rear propeller shafts for assem-
bly reference.(9) Remove front and rear propeller shafts. (Refer
to 3 - DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - REMOVAL)
(10) Support transfer case with suitable jack.
Secure transfer case to jack with safety chains.
(11) Remove nuts attaching transfer case to trans-
mission.
(12) Move transfer case assembly rearward until
free of transmission output shaft.
(13) Lower jack and move transfer case from
under vehicle.
DISASSEMBLY
Position transfer case in a shallow drain pan.
Remove drain plug and drain any remaining lubri-
cant remaining in case.
DRTRANSFER CASE - NV241 GENII 21 - 417
TRANSFER CASE - NV241 GENII (Continued)
(2) Remove retainer (Fig. 36).
(3) Remove front tabbed thrust washer (Fig. 37).
(4) Remove input gear (Fig. 38).
(5) Remove rear tabbed thrust washer from low
range gear (Fig. 39).
CLEANING
Clean the transfer case parts with a standard
parts cleaning solvent. Remove all traces of sealer
from the cases and retainers with a scraper and
3MŸ all purpose cleaner. Use compressed air to
remove solvent residue from oil feed passages in the
case halves, retainers, gears, and shafts.
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.
Fig. 36 Input Gear Retainer Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
3 - RETAINER
Fig. 37 Front Tabbed Thrust Washer Removal
1 - FRONT TABBED THRUST WASHER
Fig. 38 Input Gear Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
Fig. 39 Rear Tabbed Thrust Washer Removal
1 - LOW RANGE GEAR
2 - REAR TABBED THRUST WASHER
21 - 426 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)
(5) Install drive chain around mainshaft sprocket
(Fig. 73). Then position front sprocket over front
shaft.
(6) Raise mainshaft about 2.54 cm (one inch) and
seat front sprocket on front output shaft.
(7) If mainshaft and mode sleeve were unseated
during chain installation, align and reseat mainshaft
in input gear and hub.
(8) Install front sprocket retaining ring (Fig. 74).(9) Install spring and cup on shift rail (Fig. 75).
(10) Insert magnet in front case pocket (Fig. 76).
OIL PUMP AND REAR CASE
CAUTION: Do not remove the bolts holding the oil
pump cover to the rear case half. The oil pump
cover is aligned to the rear output shaft inner bear-
ing race and will become mis-aligned if the bolts
are loosened. If the transfer case failure has gener-
ated any debris which may have become trapped in
the oil pump. the rear case and oil pump assembly
MUST be replaced.
(1) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of front case. Keep sealer
bead width to maximum of 3/16 inch. Do not use
excessive amount of sealer as excess will be displaced
into case interior.
Fig. 73 Install Front Sprocket and Drive Chain
1 - FRONT DRIVE SPROCKET
2 - DRIVE CHAIN
3 - MAINSHAFT
Fig. 74 Front Sprocket Retaining Ring Installation
1 - FRONT SPROCKET
2 - RETAINING RING
Fig. 75 Shift Rail Spring And Cup Installation
1 - CUP
2 - SPRING
Fig. 76 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
21 - 436 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)
(2) Align oil pump with mainshaft and align shift
rail with bore in rear case. Then install rear case and
oil pump assembly (Fig. 77).
(3) Install 4-5 rear case-to front case bolts (Fig. 78)
to hold rear case in position. Tighten bolts snug but
not to specified torque at this time.
CAUTION: Verify that shift rail, and case alignment
dowels are seated before installing any bolts. Case
could be cracked if shaft rail or dowels are mis-
aligned.
(4) Apply LoctiteŸ 242 to remainder of rear case-
to-front case bolt threads and install bolts. Tighten
bolts to 20-27 N´m (15-24 ft. lbs.),
(5) Install rear output bearing snap-ring (Fig. 79)
to output shaft.
SEAL BOOT
(1) Install the front output shaft seal slinger with
Installer 8840. Install the slinger onto the shaft until
the tool contacts the rear of the output shaft.
(2) Install a new seal boot clamp onto the seal
boot.
(3)
Install the seal boot and clamp onto the slinger
hub and tighten the clamp with Crimp Tool C-4975-A.
Fig. 77 Install Rear Case
1 - REAR CASE
2 - FRONT CASE
Fig. 78 Install Case Bolts
1 - REAR CASE
2 - FRONT CASE
3 - BOLT
Fig. 79 Install Output Shaft Retaining Ring
1 - REAR OUTPUT SHAFT
2 - OUTPUT SHAFT BEARING
3 - RETAINING RING
4 - TRANSFER CASE
DRTRANSFER CASE - NV241 GENII 21 - 437
TRANSFER CASE - NV241 GENII (Continued)