sensor DODGE RAM 2003 Service Repair Manual

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.
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.
DRTRANSFER CASE - NV271 21 - 625
TRANSFER CASE - NV271 (Continued)

SHIFT FORKS AND MAINSHAFT
(1) Shift transfer case into NEUTRAL.
(2) Remove nut that retains the shift lever to sec-
tor shaft. Then remove shift lever (Fig. 19) and
spacer from the shaft.
(3) Remove the sector support with Socket 9033.
(4) Remove the transfer case position sensor (Fig.
20).(5) Loosen detent plug (Fig. 21).
(6) Remove detent plug, spring, and plunger (Fig.
22). Note that the plug has an O-ring seal. Remove
and discard this seal.
Fig. 19 Remove Manual Shift Lever
1 - SHIFT SECTOR
2 - SECTOR SUPPORT
3 - MANUAL SHIFT LEVER
Fig. 20 Remove Position Sensor
1 - FRONT CASE
2 - POSITION SENSOR
Fig. 21 Loosen the Detent Plug
1 - FRONT CASE HALF
2 - DETENT PLUG
Fig. 22 Remove Detent plug, Spring, and Plunger
1 - FRONT CASE HALF
2 - DETENT PLUG
3 - SPRING
4 - PLUNGER
21 - 630 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(13) Install the transfer case position sensor (Fig.
71). Tighten the sensor to 20-34 N´m (15-25 ft. lbs.)
torque.
(14) Install manual shift lever and spacer onto sec-
tor shaft (Fig. 72).
(15) Install washer and nut on sector shaft to
secure shift lever. Apply 1-2 drops MopartLock N'
Seal, or equivalent, to nut threads before installation.
Then tighten nut to 27-34 N´m (20-25 ft. lbs.) torque.(16) Install new o-ring on detent plug (Fig. 73).
(17) Install detent plunger, spring, and plug (Fig.
74). Tighten the plug to 16-25 N´m (12-18 ft. lbs.).
Fig. 71 Install Position Sensor
1 - FRONT CASE
2 - POSITION SENSOR
Fig. 72 Install Manual Shift Lever
1 - SHIFT SECTOR
2 - SECTOR SUPPORT
3 - MANUAL SHIFT LEVER
Fig. 73 O-Ring Installation On Detent Plug
1 - O-RING
2 - DETENT PLUG
Fig. 74 Install Detent plug, Spring, and Plunger
1 - FRONT CASE HALF
2 - DETENT PLUG
3 - SPRING
4 - PLUNGER
21 - 644 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(7) Install the front companion flange onto the
front output shaft.
(8) Install two bolts 180É apart into the front out-
put shaft companion flange.
(9) Place holder over the bolts and against the
companion flange (Fig. 90).
(10) Install a new front companion flange nut.
Tighten the companion flange nut to 176-271 N´m
(130-200 ft.lbs.).
INSTALLATION
(1) Align and seat transfer case on transmission.
Be sure transfer case input gear splines are aligned
with transmission output shaft. Align splines by
rotating transfer case rear output shaft yoke if nec-
essary. Do not install any transfer case attaching
nuts until the transfer case is completely seated
against the transmission.
(2) Install and tighten transfer case attaching
nuts. Tighten nuts to 30-41 N´m (20-30 ft.lbs.).
(3) Remove jack stand from under transmission.
(4) Align and connect propeller shafts. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - INSTALLATION)
(5) Connect vent hose and transfer case position
sensor connector.
(6) Connect shift rod to transfer case lever or floor
shift arm. Use channel lock style pliers to press rod
back into lever grommet.
(7) Adjust shift linkage, if necessary.(8) Fill transfer case with recommended transmis-
sion fluid and install fill plug.
(9) Install skid plate, if equipped. (Refer to 13 -
FRAMES & BUMPERS/FRAME/TRANSFER CASE
SKID PLATE - INSTALLATION)
(10) Lower vehicle
SPECIFICATIONS
TRANSFER CASE - NV271
TORQUE SPECIFICATIONS
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Plug, Detent 16-25 12-18 -
Plug, Drain/Fill 20-34 15-25 -
Bolt, Extension Housing 27-34 20-25 -
Bolt, Case Half 27-34 20-25 -
Nut, Range Lever 27-34 20-25 -
Sector Support 27-34 20-25 -
Nuts, Mounting 30-41 20-30 -
Position Sensor 20-34 15-25 -
Nut, Companion Flange 176-271 130-200 -
Fig. 90 Install Companion Flange Nut
1 - HOLDER 6719
2 - BOLTS
DRTRANSFER CASE - NV271 21 - 649
TRANSFER CASE - NV271 (Continued)

POSITION SENSOR
DESCRIPTION
The transfer case position sensor is an electronic
device whose output can be interpreted to indicate
the transfer case's current operating mode. The sen-
sor consists of a five position, resistive multiplexed
circuit which returns a specific resistance value to
the Powertrain Control Module (PCM) for each trans-
fer case operating mode. The sensor is located on the
top of the transfer case, just left of the transfer case
centerline and rides against the sector plate rooster-comb. The PCM supplies 5VDC (+/- 0.5V) to the sen-
sor and monitors the return voltage to determine the
sector plate, and therefore the transfer case, position.OPERATION
During normal vehicle operation, the Powertrain
Control Module (PCM) monitors the transfer case
position sensor return voltage to determine the oper-
ating mode of the transfer case. Refer to the Operat-
ing Mode Versus Resistance table for the correct
resistance for each position (Fig. 96).
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 - 654 TRANSFER CASE - NV271DR

TRANSFER CASE - NV243
TABLE OF CONTENTS
page page
TRANSFER CASE - NV243
DESCRIPTION........................658
OPERATION..........................659
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV243.......................659
REMOVAL............................660
DISASSEMBLY........................660
CLEANING...........................668
INSPECTION.........................668
ASSEMBLY...........................670
INSTALLATION........................679
SPECIFICATIONS
TRANSFER CASE - NV243.............680
SPECIAL TOOLS
TRANSFER CASE - NV241/NV243........680
EXTENSION HOUSING BUSHING AND SEAL
REMOVAL............................682
INSTALLATION........................682FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL............................682
FRONT OUTPUT SHAFT SEAL
REMOVAL............................683
INSTALLATION........................683
MODE SENSOR
DESCRIPTION........................684
OPERATION..........................684
SELECTOR SWITCH
DESCRIPTION........................685
OPERATION..........................685
SHIFT MOTOR
DESCRIPTION........................686
OPERATION..........................686
REMOVAL............................686
INSTALLATION........................686
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 - 658 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 - 660 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.
(6) Using a suitable pry tool (Fig. 7), remove the
slinger from the output shaft using care not to dam-
age the shaft.
Fig. 4 Remove Boot Clamp - Typical
1 - SEAL BOOT
2 - BOOT CLAMP
Fig. 3 Remove the Shift Motor and Mode Sensor
Assembly Bolts - Typical
1 - TRANSFER CASE
2 - SHIFT MOTOR AND MODE SENSOR ASSEMBLY
3 - BOLT
Fig. 5 Remove Seal Boot - Typical
1 - SEAL BOOT
2 - SEAL SLINGER
Fig. 6 Bend Slinger Ears - Typical
1 - SLINGER
2 - BEND UPWARD
Fig. 7 Remove Slinger From Shaft - Typical
1 - SLINGER
2-PRYTOOL
DRTRANSFER CASE - NV243 21 - 661
TRANSFER CASE - NV243 (Continued)

(9) Install spring and cup on shift rail (Fig. 71).
(10) Insert magnet in front case pocket (Fig. 72).
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.
(4) Position the shift motor and mode sensor
assembly onto the transfer case.
(5) Install the bolts 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..
Fig. 71 Shift Rail Spring And Cup Installation
1 - CUP
2 - SPRING
Fig. 72 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
Fig. 73 Install Rear Case
1 - REAR CASE
2 - FRONT CASE
21 - 678 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)

(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. 76).
(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. 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
Fig. 76 Install Rear Extension Bolts
1 - EXTENSION HOUSING
2 - TRANSFER CASE
DRTRANSFER CASE - NV243 21 - 679
TRANSFER CASE - NV243 (Continued)