1998 DODGE RAM 1500 transmission

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)

(10) Remove the rear output shaft bearing from
the rear case using Remover/Installer 8684 and Han-
dle C-4171 (Fig. 49).
(11) Install the rear output shaft bearing (Fig. 50)
into the rear case using Remover/Installer 6953 and
Handle C-4171.INPUT AND PLANETARY GEAR
(1) Lubricate gears and thrust washers (Fig. 51)
with recommended transmission fluid.
(2) Install first thrust washer in low range gear
(Fig. 51). Be sure washer tabs are properly aligned in
gear notches.
(3) Install input gear in low range gear. Be sure
input gear is fully seated.
(4) Install remaining thrust washer in low range
gear and on top of input gear. Be sure washer tabs
are properly aligned in gear notches.
(5) Install retainer on input gear and install snap-
ring.
Fig. 49 Remove Rear Output Shaft Bearing
1 - REAR CASE
2 - REMOVER/INSTALLER 8684
3 - HANDLE C-4171
Fig. 50 Install Rear Output Shaft Bearing
1 - REAR CASE
2 - REMOVER/INSTALLER 6953
3 - HANDLE C-4171
Fig. 51 Input/Low Range Gear Components
1 - SNAP-RING
2 - RETAINER PLATE
3 - INPUT GEAR
4 - LOW RANGE GEAR
5 - THRUST WASHERS
21 - 498 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)

(6) Align and install low range/input gear assem-
bly in front case (Fig. 52). Be sure low range gear
pinions are engaged in annulus gear and that input
gear shaft is fully seated in front bearing.
(7) Install snap-ring to hold input/low range gear
into front bearing (Fig. 53).
(8) Install a new input gear seal using Installer
8841 and Handle C-4171.SHIFT FORKS AND MAINSHAFT
(1) Lubricate mainshaft splines with recommended
transmission fluid.
(2) Install the mode hub (Fig. 54) onto the output
shaft.
(3) Install the mode hub retaining ring (Fig. 55)
onto the output shaft.
Fig. 52 Install Input Planetary Assembly
1 - FRONT CASE
2 - INPUT PLANETARY ASSEMBLY
Fig. 53 Install Input Gear Retaining Ring
1 - INPUT GEAR
2 - RETAINING RING
Fig. 54 Install Mode Hub
1 - OUTPUT SHAFT
2 - MODE HUB
Fig. 55 Install Mode Hub Retaining Ring
1 - OUTPUT SHAFT
2 - RETAINING RING
3 - MODE HUB
DRTRANSFER CASE - NV243 21 - 499
TRANSFER CASE - NV243 (Continued)

(8) Install the drive sprocket retaining ring (Fig.
60) onto the output shaft.
(9) Lubricate sector shaft with transmission fluid
and install shift sector in case (Fig. 61). Position slot
in sector so it will be aligned with shift fork pin
when shift forks are installed.
(10) Install the shift sector o-ring.(11) Assemble and install range fork and hub (Fig.
62). Be sure hub is properly seated in low range gear
and engaged to the input gear.
(12) Align and insert range fork pin in shift sector
slot.
(13) Install the range fork retaining ring.
(14) Install mode fork and shift rail onto the mode
sleeve.
(15) Install the mode fork, sleeve, and shift rail
into the transfer case (Fig. 63).
Fig. 63 Mode Fork And Sleeve Installation
1 - MODE SLEEVE
2 - MODE FORK AND RAIL
Fig. 60 Install The Drive Sprocket Retaining Ring
1 - OUTPUT SHAFT
2 - RETAINING RING
3 - DRIVE SPROCKET
Fig. 61 Install Shift Sector
1 - SHIFT SECTOR
Fig. 62 Install Range Fork And Hub Assembly
1 - RANGE HUB
2 - RANGE FORK
DRTRANSFER CASE - NV243 21 - 501
TRANSFER CASE - NV243 (Continued)

(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..
(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.
SPECIFICATIONS
TRANSFER CASE - NV243
TORQUE SPECIFICATIONS
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Plug, Detent 16-24 12-18 -
Plug, Drain/Fill 20-34 15-25 -
Bolt, Extension Housing 16-24 12-18 -
Bolt, Case Half 20-27 15-24 -
Screw, Oil Pump 12-16 8-12 -
Nuts, Mounting 30-41 20-30 -
Bolts, Shift Motor and
Mode Sensor Assembly16-24 12-18 -
Fig. 76 Install Rear Extension Bolts
1 - EXTENSION HOUSING
2 - TRANSFER CASE
DRTRANSFER CASE - NV243 21 - 505
TRANSFER CASE - NV243 (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. 77).
(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.
FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL
The fill and drain plugs are both in the rear case
(Fig. 78).
(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 open-
ing with MopartATF +4, Automatic Transmission 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. 79).
Fig. 79 Remove Boot Clamp
1 - SEAL BOOT
2 - BOOT CLAMP
Fig. 77 Install Rear Seal in Extension Housing
1 - SPECIAL TOOL C-4171
2 - SPECIAL TOOL D-163
Fig. 78 Fill/Drain Plug and I.D. Tag Location
1 - I.D. TAG
2 - FILL PLUG
3 - DRAIN PLUG
DRTRANSFER CASE - NV243 21 - 507

²A flashing operating mode LED for the desired
gear indicates that a shift to that position has been
requested, but all of the driver controllable conditions
have not been met. This is in an attempt to notify the
driver that the transmission needs to be put into NEU-
TRAL, the vehicle speed is too great, or some other con-
dition outlined (other than a diagnostic failure that
would prevent this shift) elsewhere (Refer to 8 - ELEC-
TRICAL/ELECTRONIC CONTROL MODULES/TRANS-
FER CASE CONTROL MODULE - OPERATION) is not
met. Note that this flashing will continue indefinitely
until the conditions are eventually met, or the selector
switch position is changed, or if diagnostic routines no
longer allow the requested shift.
²If the driver attempts to make a shift into transfer
case NEUTRAL, and any of the driver controllable con-
ditions are not met, the request will be ignored until all
of the conditions are met or until the NEUTRAL select
button is released. Additionally the neutral lamp will
flash, or begin to flash while the button is depressed
and operator controllable conditions are not being met.
All of the LED's except the Neutral will flash if any of
the operator controllable conditions for shifting are not
met while the Neutral button is depressed. This9toggle9
type of feature is necessary because the TCCM would
interpret another request immediately after the shift
into transfer case NEUTRAL has completed.
²No LED's illuminated indicate a fault in the
transfer case control system.
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 assembly 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 - NV243 21 - 511
SELECTOR SWITCH (Continued)