1998 DODGE RAM 1500 Fig

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, if necessary.
(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 rear output bearing snap-ring (Fig. 74)
to output shaft.
(6) Install 4-5 rear case-to front case bolts (Fig. 75)
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.(7) Apply MopartLock 'n Seal Adhesive to remain-
der of rear case-to-front case bolt threads and install
bolts. Tighten bolts to 25-28 N´m (18-21 ft. lbs.),
Fig. 73 Install Rear Case
1 - REAR CASE
2 - FRONT CASE
Fig. 74 Install Output Shaft Retaining Ring
1 - REAR OUTPUT SHAFT
2 - OUTPUT SHAFT BEARING
3 - RETAINING RING
4 - TRANSFER CASE
Fig. 75 Install Case Bolts
1 - REAR CASE
2 - FRONT CASE
3 - BOLT
DRTRANSFER CASE - NV244 GENII 21 - 533
TRANSFER CASE - NV244 GENII (Continued)

SEAL BOOT AND SHIFT MOTOR ASSEMBLY
(1) Install a new seal boot clamp onto the seal
boot.
(2) Install the seal boot (Fig. 76) and clamp onto
the slinger hub and tighten the clamp with Crimp
Tool C-4975-A.
(3) Position the shift motor and mode sensor
assembly onto the transfer case.
(4) Install the bolts (Fig. 77) to hold the shift
motor and mode sensor assembly to the transfer
case. Tighten the bolts to 16-25 N´m (12-18 ft. lbs.).
REAR EXTENSION
(1) Install new seal in rear extension housing seal
with Installer D-163 and Handle C-4171. Verify that
the weep hole in the rubber is oriented downward.
(2) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of rear extension housing.
Keep sealer bead width to maximum of 3/16 inch. Do
not use excessive amount of sealer as excess could be
displaced into output bearing.
(3) Align and install rear extension on retainer
(Fig. 78).
(4) Apply MopartSilicone Sealer to threads of rear
extension housing bolts. Then install and tighten
bolts to 16-24 N´m (12-18 ft. lbs.) torque.
INSTALLATION
(1) Mount transfer case on a transmission jack.
(2) Secure transfer case to jack with chains.
(3) Position transfer case under vehicle.
(4) Align transfer case and transmission shafts
and install transfer case onto the transmission.
(5) Install and tighten transfer case attaching nuts
to 27-34 N´m (20-25 ft. lbs.) torque.
(6) Connect the vent hose.
(7) Connect the shift motor and mode sensor wir-
ing connectors. Secure wire harness to clips on trans-
fer case.
(8) Align and connect the propeller shafts.
(9) Fill transfer case with correct fluid. (Refer to
21 - TRANSMISSION/TRANSFER CASE/FLUID -
STANDARD PROCEDURE)
(10) Install skid plate, if equipped.
(11) Remove transmission jack and support stand.
(12) Lower vehicle and verify transfer case shift
operation.
Fig. 76 Install Seal Boot
1 - SEAL BOOT
2 - SEAL SLINGER
Fig. 77 Install the Shift Motor and Mode Sensor
Assembly Bolts - Typical
1 - TRANSFER CASE
2 - SHIFT MOTOR AND MODE SENSOR ASSEMBLY
3 - BOLT
Fig. 78 Install Rear Extension Bolts
1 - EXTENSION HOUSING
2 - TRANSFER CASE
21 - 534 TRANSFER CASE - NV244 GENIIDR
TRANSFER CASE - NV244 GENII (Continued)

EXTENSION HOUSING SEAL
REMOVAL
(1) Raise and support vehicle.
(2) Remove rear propeller shaft. (Refer to 3 - DIF-
FERENTIAL & DRIVELINE/PROPELLER SHAFT/
PROPELLER SHAFT - REMOVAL)
(3) Using a suitable pry tool or slide-hammer
mounted screw, remove the extension housing seal.
INSTALLATION
(1) Clean fluid residue from sealing surface and
inspect for defects.
(2) Using Installer D-163, install seal in extension
housing (Fig. 79).
(3) Install propeller shaft. (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/PROPELLER SHAFT/PRO-
PELLER SHAFT - INSTALLATION)
(4) Verify proper transfer case fluid level.
(5) Lower vehicle.
Installer, Bushing - 5066
Installer, Bearing - 6953
Cup - 8148
Installer - 8840
Installer, Seal - 8841
Fig. 79 Install Rear Seal in Extension Housing
1 - SPECIAL TOOL C-4171
2 - SPECIAL TOOL D-163
21 - 536 TRANSFER CASE - NV244 GENIIDR
TRANSFER CASE - NV244 GENII (Continued)

FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL
The fill and drain plugs are both in the rear case
(Fig. 80).
(1) Raise vehicle.
(2) Position drain pan under transfer case.
(3) Remove drain and fill plugs and drain lubri-
cant completely.
(4) Install drain plug. Tighten plug to 20-34 N´m
(15-25 ft. lbs.).
(5) Remove drain pan.
(6) Fill transfer case to bottom edge of fill plug
opening with MopartATF +4, Automatic Transmis-
sion fluid.
(7) Install and tighten fill plug to 20-34 N´m
(15-25 ft. lbs.).
(8) Lower vehicle.
FRONT OUTPUT SHAFT SEAL
REMOVAL
(1) Remove the front propeller shaft (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - REMOVAL).
(2) Remove the front propeller shaft seal boot
retaining clamp (Fig. 81).
(3) Remove the front propeller shaft seal boot (Fig.
82).
Fig. 80 Fill/Drain Plug and I.D. Tag Location
1 - I.D. TAG
2 - FILL PLUG
3 - DRAIN PLUG
Fig. 81 Remove Boot Clamp
1 - SEAL BOOT
2 - CLAMP
Fig. 82 Remove Seal Boot
1 - SEAL BOOT
2 - SEAL SLINGER
DRTRANSFER CASE - NV244 GENII 21 - 537

(4) Remove the front output shaft seal slinger by
bending (Fig. 83) the slinger away from the transfer
case.
(5) Using a suitable pry tool, remove the slinger
from the output shaft using care not to damage the
shaft.
(6) Using a screw and a slide hammer, remove the
front output shaft seal.
INSTALLATION
(1) Install the new front output shaft seal with
Installer MB991168A
(2) 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.
(3) Install a new seal boot clamp onto the seal
boot.
(4) Install the seal boot and clamp onto the slinger
hub and tighten the clamp with Crimp Tool
C-4975-A.
(5) Install front propeller shaft (Refer to 3 - DIF-
FERENTIAL & DRIVELINE/PROPELLER SHAFT/
PROPELLER SHAFT - INSTALLATION).
MODE SENSOR
DESCRIPTION
The transfer case mode sensor (Fig. 84) is an elec-
tronic device whose output can be interpreted to indi-
cate the shift motor shaft's rotary position. The
sensor consists of a magnetic ring and four Hall
Effect Transistors to create a 4 channel digital device
(non-contacting) whose output converts the motor
shaft position into a coded signal. The TCCM must
supply 5VDC (+/- 0.5v) to the sensor and monitor the
shift motor position. The four channels are denoted
A, B, C, and D. The sensor is mechanically linked to
the shaft of the cam which causes the transfer case
shifting. The mode sensor draws less than 53 mA.
Fig. 83 Bend Slinger Upward
1 - SEAL SLINGER
2 - BEND UPWARD
Fig. 84 Mode Sensor - Typical
1 - MODE SENSOR
21 - 538 TRANSFER CASE - NV244 GENIIDR
FRONT OUTPUT SHAFT SEAL (Continued)

SHIFT MOTOR
DESCRIPTION
The shift motor (Fig. 85) consists of a permanent
magnet D.C. motor with gear reduction to convert a
high speed-low torque device into a low speed-high
torque device. The output of the device is coupled to
a shaft which internally moves the mode and range
forks that change the transfer case operating ranges.
The motor is rated at 25 amps maximum at 72É F
with 10 volts at the motor leads.
OPERATION
The transfer case shift motor responds to the
Transfer Case Control Module (TCCM) commands to
move the transfer case shift sector bi-directionally, as
required, to obtain the transfer case operating mode
indicated by the instrument panel mounted selector
switch.
REMOVAL
NOTE: New shift motor assemblies are shipped in
the 2WD/AWD position. If a new shift motor assem-
bly will be installed, it will be necessary to shift the
transfer case to the 2WD/AWD position prior to
motor removal.
(1) Raise the vehicle on a suitable hoist.
(2) Disengage the wiring connectors from the shift
motor and mode sensor.
(3) Remove the bolts holding the shift motor and
mode sensor assembly onto the transfer case.
(4) Separate the shift motor and mode sensor
assembly from the transfer case.
INSTALLATION
(1) Verify that the shift sector o-ring is clean and
properly positioned over the shift sector and against
the transfer case.
NOTE: Verify that the shift motor position and sec-
tor shaft orientation are aligned. It may be neces-
sary to manually shift the transfer case if the shift
motor and sector shaft are not aligned.
(2) Position the shift motor and mode sensor
assembly onto the transfer case.
(3) Install the bolts to hold the assembly onto the
transfer case. Tighten the bolts to 16-24 N´m (12-18
ft.lbs.).
CAUTION: If the original shift motor and mode sen-
sor assembly bolts are reused, be sure to use
MoparTLock & Seal or LoctiteŸ 242 to replenish
the lock patch material originally found on the bolts
(4) Engage the wiring connectors to the shift motor
and mode sensor.
(5) Refill the transfer case as necessary.
(6) Lower vehicle and verify transfer case opera-
tion.
Fig. 85 Shift Motor - Shown Inverted - Typical
1 - SHIFT MOTOR
DRTRANSFER CASE - NV244 GENII 21 - 541

IDENTIFICATION
A circular ID tag is attached to the rear case of
each transfer case (Fig. 1). The ID 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
The input gear is splined to the transmission out-
put shaft. The input gear drives the mainshaft
through the planetary assembly and range sleeve.
The front output shaft is operated by a drive chain
that connects the shaft to a drive sprocket on the
mainshaft. The drive sprocket is engaged/disengaged
by the mode fork, which operates the mode sleeve
and hub. The sleeve and hub are not equipped with a
synchronizer mechanism for shifting.
DIAGNOSIS AND TESTING - TRANSFER CASE - NV273
DIAGNOSIS CHART
Condition Possible Cause Correction
Transfer case difficult to shift or will
not shift into desired range.1) Transfer case electronically
controlled shift system malfunction.1) Verify proper operation per the
appropriate diagnostic manual.
2) If vehicle was operated for an
extended period in 4HI mode on
dry surface, driveline torque load
may cause difficulty.2) Drive the vehicle in a straight line
and momentarily release the
accelerator. The transfer case can
then be shifted to the desired mode.
3) Insufficient or incorrect lubricant. 3) Drain and refill transfer case with
the correct quantity of MoparTAT F
+4, Automatic Transmission Fluid.
4) Internal transfer case
components binding, worn, or
damaged.4) Repair or replace components as
necessary.
Transfer case noisy in all drive
modes.1) Insufficient or incorrect lubricant. 1) Drain and refill transfer case with
the correct quantity of MoparTAT F
+4, type 9602, Automatic
Transmission Fluid.
2) Internal transfer case
components binding, worn, or
damaged.2) Repair or replace components as
necessary.
Fig. 1 Transfer Case - Rear View
1 - TRANSFER CASE
2 - IDENTIFICATION TAG
DRTRANSFER CASE - NV273 21 - 543
TRANSFER CASE - NV273 (Continued)

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 - 544 TRANSFER CASE - NV273DR
TRANSFER CASE - NV273 (Continued)