DODGE RAM 1500 1998 2.G Workshop Manual

OPERATING MODE VERSUS RESISTANCE
SENSOR POSITION OPERATING MODE SENSOR RESISTANCE (ohms)
1 2H 1172-1195
2 4H 677-691
3 NEUTRAL 406-415
4 4L 208-213
5 NOT USED 60-61
REMOVAL
(1) Raise and support the vehicle.
(2) Disengage the transfer case position sensor
connector from the position sensor.
(3) Remove the position sensor from the transfer
case.
INSTALLATION
(1) Inspect the o-ring seal on the transfer case
position sensor. Replace the o-ring if necessary.
(2) Install the transfer case position sensor into
the transfer case. Torque the sensor to 20-34 N´m
(15-25 ft.lbs.).
(3) Engage the transfer case position sensor con-
nector to the position sensor.
(4) Lower vehicle.
(5) Verify proper sensor operation.
Fig. 96 Position Sensor Linear Movement
1 - POSITION 1 - 10mm  0.5mm
2 - POSITION 2 - 12mm  0.5mm
3 - POSITION 3 - 14mm  0.5mm
4 - POSITION 4 - 16mm  0.5mm
5 - POSITION 5 - 18mm  0.5mm
6 - POSITION 6 - 20mm  0.5mm - FULL EXTENSION
21 - 478 TRANSFER CASE - NV271DR
POSITION SENSOR (Continued)

SHIFT LEVER
REMOVAL
(1) Shift transfer case into 2H.
(2) Raise and support the vehicle.
(3) Loosen adjusting trunnion lock bolt and slide
shift rod out of trunnion. If rod lacks enough travel
to come out of trunnion, push trunnion out of shift
lever.
(4) Lower vehicle.
(5) Remove transfer case shifter knob cap.
(6) Remove nut holding shifter knob to shift lever.
(7) Remove shifter knob.
(8) Remove the shift boot from the shifter console.
(9) Remove the bolts securing the shifter mecha-
nism to the floor pan (Fig. 97).
(10) Separate shift lever mechanism from the vehi-
cle.
Fig. 97 Transfer Case Shifter
1 - SHIFTER BOOT 4 - SHIFTER MECHANISM
2 - SHIFTER KNOB 5 - ALIGNMENT PIN
3 - SHIFTER CONSOLE 6 - TRANSFER CASE
DRTRANSFER CASE - NV271 21 - 479

INSTALLATION
(1) If the shifter mechanism does not have a
adjustment locating pin installed, align the adjust-
ment channel on the shifter assembly to the locating
hole in the lower shift lever and install an appropri-
ately sized pin to retain the position (Fig. 98).
(2) Position shift lever in vehicle.
(3) Install the bolts to hold the shifter mechanism
to the floor pan.
(4) Raise vehicle.
(5) Verify that the transfer case is still in the 2H
position. The 2H detent position on the transfer case
shift arm is the second position from full forward.(6) Install trunnion to shift lever, if necessary.
(7) Install shift rod to trunnion, if necessary.
(8) Tighten the shift rod lock bolt to 10 N´m (90
in.lbs.).
(9) Remove the shifter adjustment locating pin
from the adjustment channel and the locating hole.
(10) Lower vehicle.
(11) Install the transfer case shifter console.
(12) Install the shifter boot and the shifter knob
onto the shifter lever.
(13) Install nut to hold shifter knob to shift lever.
(14) Install shifter knob cap.
(15) Verify transfer case operation.
Fig. 98 Transfer Case Shifter
1 - SHIFTER BOOT 4 - SHIFTER MECHANISM
2 - SHIFTER KNOB 5 - ALIGNMENT PIN
3 - SHIFTER CONSOLE 6 - TRANSFER CASE
21 - 480 TRANSFER CASE - NV271DR
SHIFT LEVER (Continued)

ADJUSTMENTS
ADJUSTMENT - SHIFT LEVER
(1) Move shift lever into 2H position.
(2) Raise vehicle.
(3) Loosen shift rod lock bolt at trunnion.
(4) Check shift rod fit in trunnion. Be sure rod
does not bind in trunnion. Lubricate the shift rod
and trunnion if necessary.
(5) Verify that transfer case shift lever is in 2H
detent position. The 2H detent position on the trans-
fer case shift arm is the second position from full for-
ward.
(6) Align the adjustment locating hole on the lower
shifter lever with the adjustment channel on the
shifter bracket assembly (Fig. 99).(7) Insert an appropriately sized pin through into
the adjustment channel and through the locating
hole to hold the shifter in the correct position.
(8) Tighten shift rod lock bolt to 10 N´m (90 in.
lbs.) torque.
(9) Remove the locating pin from the adjustment
channel and locating hole.
(10) Check shift linkage operation. Be sure trans-
fer case shifts into and operates properly in all
ranges.
Fig. 99 Transfer Case Shifter
1 - SHIFTER BOOT 4 - SHIFTER MECHANISM
2 - SHIFTER KNOB 5 - ALIGNMENT PIN
3 - SHIFTER CONSOLE 6 - TRANSFER CASE
DRTRANSFER CASE - NV271 21 - 481
SHIFT LEVER (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

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 - NV243
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 Fill/Drain Plug And I.D. Tag Locations
1 - I.D. TAG
2 - FILL PLUG
3 - DRAIN PLUG
DRTRANSFER CASE - NV243 21 - 483
TRANSFER CASE - NV243 (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 - 484 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)

SHIFT MOTOR ASSEMBLY AND FRONT OUTPUT
SHAFT SEAL
(1) Remove the bolts (Fig. 3) which hold the shift
motor and mode sensor assembly to the transfer
case.
(2) Remove the shift motor and mode sensor
assembly from the transfer case.
(3) Remove the front propeller shaft seal boot
retaining clamp (Fig. 4).(4) Remove the front propeller shaft seal boot (Fig.
5).
(5) Remove the front output shaft seal slinger by
bending (Fig. 6) the slinger ears away from the
transfer case.
Fig. 4 Remove Boot Clamp - Typical
1 - SEAL BOOT
2 - BOOT CLAMP
Fig. 5 Remove Seal Boot - Typical
1 - SEAL BOOT
2 - SEAL SLINGER
Fig. 6 Bend Slinger Ears - Typical
1 - SLINGER
2 - BEND UPWARD
Fig. 3 Remove the Shift Motor and Mode Sensor
Assembly Bolts - Typical
1 - TRANSFER CASE
2 - SHIFT MOTOR AND MODE SENSOR ASSEMBLY
3 - BOLT
DRTRANSFER CASE - NV243 21 - 485
TRANSFER CASE - NV243 (Continued)

(6) Using a suitable pry tool (Fig. 7), remove the
slinger from the output shaft using care not to dam-
age the shaft.
(7) Using a screw and a slide hammer, remove the
front output shaft seal.
REAR EXTENSION
(1) Remove rear extension bolts (Fig. 8).(2) Remove rear extension housing (Fig. 9). Tap
extension once or twice with a plastic mallet to break
sealer bead and loosen it.
(3) Remove output bearing retaining ring with
heavy duty snap-ring pliers (Fig. 10).
Fig. 7 Remove Slinger From Shaft - Typical
1 - SLINGER
2-PRYTOOL
Fig. 8 Remove Rear Extension Bolts
1 - EXTENSION HOUSING
2 - TRANSFER CASE
Fig. 9 Remove Rear Extension
1 - EXTENSION HOUSING
2 - TRANSFER CASE
3 - PRY SLOT
Fig. 10 Remove Output Shaft Retaining Ring
1 - REAR OUTPUT SHAFT
2 - OUTPUT SHAFT BEARING
3 - RETAINING RING
4 - TRANSFER CASE
21 - 486 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)

OIL PUMP AND REAR CASE
(1) Remove rear case-to-front case bolts (Fig. 11).
(2) Loosen rear case with pry tool to break sealer
bead. Insert tool in slot at each end of case (Fig. 12).(3) Unseat rear case from alignment dowels.
(4) Remove rear case and oil pump assembly from
front case (Fig. 13).
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.
(5) Remove the oil pump pickup tube.
FRONT OUTPUT SHAFT AND DRIVE CHAIN
(1) Remove shift rail cup and spring (Fig. 14).
Fig. 11 Remove Case Bolts
1 - REAR CASE
2 - FRONT CASE
3 - BOLT
Fig. 12 Loosen Case Halves
1 - REAR CASE
2 - FRONT CASE
3 - PRY SLOTS
Fig. 13 Remove Rear Case
1 - REAR CASE
2 - FRONT CASE
Fig. 14 Shift Rail Cup And Spring Removal
1 - SHIFT RAIL
2 - SPRING
3 - CUP
DRTRANSFER CASE - NV243 21 - 487
TRANSFER CASE - NV243 (Continued)