1998 DODGE RAM 1500 rear main seal

TRANSFER CASE - NV271
TABLE OF CONTENTS
page page
TRANSFER CASE - NV271
DESCRIPTION........................447
OPERATION..........................448
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV271.......................448
REMOVAL............................450
DISASSEMBLY........................450
CLEANING...........................459
INSPECTION.........................459
ASSEMBLY...........................461
INSTALLATION........................473
SPECIFICATIONS
TRANSFER CASE - NV271.............473
SPECIAL TOOLS
TRANSFER CASE NV271/NV273.........474
EXTENSION HOUSING SEAL AND DUST BOOT
REMOVAL............................476INSTALLATION........................476
FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL............................476
FRONT OUTPUT SHAFT SEAL
REMOVAL............................477
INSTALLATION........................477
POSITION SENSOR
DESCRIPTION........................477
OPERATION..........................477
REMOVAL............................478
INSTALLATION........................478
SHIFT LEVER
REMOVAL............................479
INSTALLATION........................480
ADJUSTMENTS
ADJUSTMENT - SHIFT LEVER..........481
TRANSFER CASE - NV271
DESCRIPTION
The NV271 transfer case is a part-time transfer
case with a low-range gear system. It provides three
operating ranges plus a NEUTRAL position. 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.
Fig. 1 Transfer Case - Front View
1 - TRANSFER CASE
2 - MANUAL LEVER
3 - POSITION SENSOR
DRTRANSFER CASE - NV271 21 - 447

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.
COMPANION FLANGE AND EXTENSION HOUSING
(1) Install two bolts 180É apart into the front out-
put shaft companion flange.
(2) Place holder over the bolts and against the
companion flange (Fig. 3).
(3) Remove and discard the front companion flange
nut.
(4) Remove the companion flange from the front
output shaft. It may be necessary to use Flange
puller 8992 to remove the companion flange.
(5) Use a suitable chisel or pry tool to remove the
rear extension housing dust boot (Fig. 4).
(6) Use a suitable chisel or pry tool to remove the
rear extension housing seal.
Fig. 3 Remove Companion Flange Nut
1 - HOLDER 6719
2 - BOLTS
Fig. 4 Remove Extension Housing Dust Boot
1 - EXTENSION HOUSING
2 - DUST BOOT
21 - 450 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(8) Install front sprocket retaining ring (Fig. 78).
(9) Install rear sprocket retaining ring (Fig. 79).
(10) Install spring onto shift rail (Fig. 80).
(11) Insert magnet in front case pocket (Fig. 81).
REAR CASE
(1) Install the oil pick-up tube and screen into the
rear case half.
(2) 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.
(3) Align mainshaft with he rear output shaft
bearing and align shift rail with bore in rear case.
Then install rear case (Fig. 82). Verify that the case
alignment dowels correctly seat into their mating
recesses.
(4) Install 4-5 rear case-to front case bolts (Fig. 83)
to hold rear case in position. Tighten bolts snug but
not to specified torque at this time.
Fig. 78 Install Front Output Shaft Sprocket
Retaining Ring
1 - FRONT OUTPUT SHAFT
2 - DRIVE SPROCKET
3 - RETAINING RING
Fig. 79 Install Rear Output Shaft Sprocket Retaining
Ring
1 - REAR OUTPUT SHAFT
2 - DRIVE SPROCKET
3 - RETAINING RING
Fig. 80 Install Shift Rail Spring
1 - SHIFT RAIL
2 - SPRING
Fig. 81 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
21 - 470 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

TRANSFER CASE - NV243
TABLE OF CONTENTS
page page
TRANSFER CASE - NV243
DESCRIPTION........................482
OPERATION..........................483
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV243.......................483
REMOVAL............................484
DISASSEMBLY........................484
CLEANING...........................493
INSPECTION.........................493
ASSEMBLY...........................496
INSTALLATION........................505
SPECIFICATIONS
TRANSFER CASE - NV243.............505
SPECIAL TOOLS
TRANSFER CASE - NV243.............506
EXTENSION HOUSING SEAL
REMOVAL............................507
INSTALLATION........................507FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL............................507
FRONT OUTPUT SHAFT SEAL
REMOVAL............................507
INSTALLATION........................508
MODE SENSOR
DESCRIPTION........................509
OPERATION..........................509
SELECTOR SWITCH
DESCRIPTION........................510
OPERATION..........................510
SHIFT MOTOR
DESCRIPTION........................511
OPERATION..........................511
REMOVAL............................511
INSTALLATION........................511
TRANSFER CASE - NV243
DESCRIPTION
The NV243 is an electronically controlled part-time
transfer case with a low range gear reduction system.
The NV243 has three operating ranges plus a NEU-
TRAL position. The low range system provides a gear
reduction ratio for increased low speed torque capa-
bility.
The geartrain is mounted in two aluminum case
halves attached with bolts. The mainshaft front and
rear bearings are mounted in aluminum retainer
housings bolted to the case halves.
OPERATING RANGES
Transfer case operating ranges are:
²2WD (2-wheel drive)
²4HI (4-wheel drive)
²4LO (4-wheel drive low range)
²NEUTRAL
The 2WD range is for use on any road surface at
any time.The 4HI 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 wet or slip-
pery or covered by ice and snow.
The low range reduction gear system is operative
in 4LO range only. This range is for extra pulling
power in off road situations. Low range reduction
ratio is 2.72:1.
SHIFT MECHANISM
Operating ranges are selected with a dash
mounted shift selector switch. The shift selector
switch provides a input to the Transfer Case Control
Module (TCCM) to indicate the driver's desire to
change operating ranges. The TCCM uses this input,
along with input from the transfer case mounted
mode sensor and information from the vehicle's bus,
to determine if a shift is permitted. If the TCCM
decides the shift is permitted, the TCCM controls the
shift motor, mounted to the exterior of the transfer
case, to perform the shift.
21 - 482 TRANSFER CASE - NV243DR

Condition Possible Cause Correction
Transfer case noisy while in, or
jumps out of, 4LO mode.1) Transfer case not completely
engaged in 4LO position.1) While rolling 2-3 MPH and the
transmission in NEUTRAL, or clutch
depressed on vehicles equipped
with a manual transmission, shift
transfer case to the 2WD or 4HI
position, and then back into the 4LO
position.
2) Range fork damaged, inserts
worn, or fork is binding on the shift
rail.2) Repair or replace components as
necessary.
3) Low range gear worn or
damaged.3) Repair or replace components as
necessary.
Lubricant leaking from transfer case
seals or vent.1) Transfer case overfilled. 1) Drain lubricant to the correct
level.
2) Transfer case vent closed or
restricted.2) Clean or replace vent as
necessary.
3) Transfer case seals damaged or
installed incorrectly.3) Replace suspect seal.
Abnormal tire wear. 1) Extended operation in 4HI mode
on dry surfaces,1) Operate vehicle in 2WD mode on
dry surfaces.
REMOVAL
(1) Shift transfer case into 2WD.
(2) Raise vehicle.
(3) Drain transfer case lubricant.
(4) Mark front and rear propeller shafts for align-
ment reference.
(5) Support transmission with jack stand.
(6) Remove the transfer case skid plate, if
equipped.
(7) Disconnect front and rear propeller shafts at
transfer case.
(8) Disconnect transfer case shift motor and mode
sensor wire connectors.
(9) Disconnect transfer case vent hose.
(10) Support transfer case with transmission jack.
(11) Secure transfer case to jack with chains.
(12) Remove nuts attaching transfer case to trans-
mission (Fig. 2).
(13) Pull transfer case and jack rearward to disen-
gage transfer case.
(14) Remove 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.
Fig. 2 Remove Transfer Case - Typical
1 - TRANSMISSION
2 - TRANSFER CASE
3 - MODE SENSOR CONNECTOR
21 - 484 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)

(2) Remove retainer (Fig. 35).
(3) Remove front tabbed thrust washer (Fig. 36).
(4) Remove input gear (Fig. 37).
(5) Remove rear tabbed thrust washer from low
range gear (Fig. 38).
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 INSPECTION
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. 35 Input Gear Retainer Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
3 - RETAINER
Fig. 36 Front Tabbed Thrust Washer Removal
1 - FRONT TABBED THRUST WASHER
Fig. 37 Input Gear Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
Fig. 38 Rear Tabbed Thrust Washer Removal
1 - LOW RANGE GEAR
2 - REAR TABBED THRUST WASHER
DRTRANSFER CASE - NV243 21 - 493
TRANSFER CASE - NV243 (Continued)

OIL PUMP AND REAR CASE
Lubricate the oil pump components with transmis-
sion fluid before installation. Prime the oil pickup
tube by pouring a little oil into the tube before instal-
lation.
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) Install new o-ring in pickup tube inlet of oil
pump.
(2) Insert oil pickup tube into the oil pump.
(3) 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.
(4) Align oil pump with mainshaft and align shift
rail with bore in rear case. Then install rear case and
oil pump assembly (Fig. 73).
(5) Install 4-5 rear case-to front case bolts (Fig. 74)
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.(6) 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.),
(7) Install rear output bearing snap-ring (Fig. 75)
to output shaft.
SEAL BOOT AND SHIFT MOTOR ASSEMBLY
(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. 73 Install Rear Case
1 - REAR CASE
2 - FRONT CASE
Fig. 74 Install Case Bolts - Typical
1 - REAR CASE
2 - FRONT CASE
3 - BOLT
Fig. 75 Install Output Shaft Retaining Ring
1 - REAR OUTPUT SHAFT
2 - OUTPUT SHAFT BEARING
3 - RETAINING RING
4 - TRANSFER CASE
21 - 504 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)

TRANSFER CASE - NV244 GENII
TABLE OF CONTENTS
page page
TRANSFER CASE - NV244 GENII
DESCRIPTION........................512
OPERATION..........................513
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV244.......................513
REMOVAL............................514
DISASSEMBLY........................514
CLEANING...........................523
INSPECTION.........................523
ASSEMBLY...........................525
INSTALLATION........................534
SPECIFICATIONS
TRANSFER CASE - NV244 GENII........535
SPECIAL TOOLS
TRANSFER CASE - NV244 GENII........535
EXTENSION HOUSING SEAL
REMOVAL............................536
INSTALLATION........................536FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL............................537
FRONT OUTPUT SHAFT SEAL
REMOVAL............................537
INSTALLATION........................538
MODE SENSOR
DESCRIPTION........................538
OPERATION..........................539
SELECTOR SWITCH
DESCRIPTION........................539
OPERATION..........................540
SHIFT MOTOR
DESCRIPTION........................541
OPERATION..........................541
REMOVAL............................541
INSTALLATION........................541
TRANSFER CASE - NV244
GENII
DESCRIPTION
The NV244 GENII is an electronically controlled
full and part-time transfer case with no two wheel
drive operation.
A differential in the transfer case is used to control
torque transfer to the front and rear axles. A low
range gear reduction system provides increased low
speed torque capability for off road operation. The
low range provides a 2.72:1 reduction ratio.
The geartrain is mounted in two aluminum case
halves attached with bolts. The mainshaft front and
rear bearings are mounted in aluminum retainer
housings bolted to the case halves.
OPERATING RANGES
NV244 GENII operating ranges are:
²AWD(All-Wheel Drive)
²4HI (Part-time)
²4LO
²NEUTRAL
The AWD mode can be used at any time and on
any road surface.The 4HI (Part-time) and 4LO ranges are for off
road use only. The only time these ranges can be
used is when the road surface is covered with snow,
ice, or other loose slippery material.
SHIFT MECHANISM
Operating ranges are selected with a dash
mounted shift selector switch. The shift selector
switch provides a input to the Transfer Case Control
Module (TCCM) to indicate the driver's desire to
change operating ranges. The TCCM uses this input,
along with the input from the transfer case mounted
mode sensor and information from the vehicle's bus,
to determine if a shift is permitted. If the TCCM
decides the shift is permitted, the TCCM controls the
shift motor, mounted to the exterior of the transfer
case, to perform the shift.
21 - 512 TRANSFER CASE - NV244 GENIIDR