2003 DODGE RAM 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 - 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
21 - 688 TRANSFER CASE - NV273DR
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
DRTRANSFER CASE - NV273 21 - 689
TRANSFER CASE - NV273 (Continued)

(17) Install the rear output shaft bearing (Fig. 54)
into the rear case using Installer 8152 and Handle
C-4171.
(18) Install the rear output shaft bearing snap-
ring into the rear case half.
INPUT AND PLANETARY GEAR
(1) Lubricate gears and thrust washers with rec-
ommended transmission fluid.
(2) Install bottom thrust washer (Fig. 55) in low
range gear planetary. Be sure washer tabs are prop-
erly aligned in gear notches.
(3) Install input gear in low range gear (Fig. 56).
Be sure input gear is fully seated.
Fig. 54 Install Rear Output Shaft Bearing
1 - REAR CASE HALF
2 - HANDLE C-4171
3 - INSTALLER 8152
Fig. 55 Install Bottom Input Gear Thrust Plate
1 - PLANETARY
2 - THRUST PLATE
Fig. 56 Install Input Gear From Planetary
1 - INPUT GEAR
2 - LOW RANGE PLANETARY
21 - 704 TRANSFER CASE - NV273DR
TRANSFER CASE - NV273 (Continued)

(7) Install snap-ring to hold input/low range gear
into front bearing (Fig. 61).
(8) Install a new input gear seal using Installer
8841 and Handle C-4171.
(9) Install a new input gear oil seal with Installer
9036 and Handle C-4171.
SHIFT FORKS AND MAINSHAFT
(1) Lubricate mainshaft splines with recommended
transmission fluid.
(2) Coat the interior of the drive sprocket hub with
ATF+4 and install the drive sprocket drive hub (Fig.
62) onto the mainshaft.(3) Install the mode hub (Fig. 63) onto the main-
shaft.
(4) Install the mode hub retaining ring (Fig. 64)
onto the mainshaft.
Fig. 61 Install Input Gear Retaining Ring
1 - INPUT GEAR
2 - RETAINING RING
Fig. 62 Install the Drive Sprocket Drive Hub
1 - MAINSHAFT
2 - DRIVE SPROCKET DRIVE HUB
Fig. 63 Install Mode Hub
1 - MAINSHAFT
2 - MODE HUB
Fig. 64 Install Mode Hub Retaining Ring
1 - MAINSHAFT
2 - MODE HUB
3 - RETAINING RING
21 - 706 TRANSFER CASE - NV273DR
TRANSFER CASE - NV273 (Continued)

(5) Install the clutch gear (Fig. 65) onto the output
shaft. Verify that the pointed ends of the clutch gear
teeth are pointing to the front of the mainshaft.
(6) Lubricate sector shaft with transmission fluid
and install shift sector in case (Fig. 66). Position slot
in sector so it will be aligned with shift fork pin
when shift forks are installed.
(7) Apply LoctiteŸ 242, or equivalent, to the
threads of the sector support to replentish the factory
applied patch. Install the shift sector support.
Tighten the sector support with Socket 9033 to 27-34
N´m (20-25 ft.lbs.).
(8) Assemble and install range fork and hub (Fig.
67). Be sure hub is properly seated in low range gear
and engaged to the input gear.(9) Align and insert range fork pin in shift sector
slot.
(10) Install mode fork and shift rail onto the mode
sleeve.
(11) Install the mode fork, sleeve, and shift rail
into the transfer case (Fig. 68).
Fig. 65 Install Clutch Gear
1 - OUTPUT SHAFT
2 - CLUTCH GEAR
3 - MODE HUB
Fig. 66 Install Shift Sector
1 - SHIFT SECTOR
Fig. 67 Install Range Fork And Hub Assembly
1 - RANGE HUB
2 - RANGE FORK
Fig. 68 Mode Fork And Sleeve Installation
1 - MODE SLEEVE
2 - MODE FORK AND RAIL
DRTRANSFER CASE - NV273 21 - 707
TRANSFER CASE - NV273 (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. 88).
(10) Install a new front companion flange nut.
Tighten the companion flange nut to 176-271 N´m
(130-200 ft.lbs.).
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 - NV273
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 27-34 20-25 -
Bolt, Case Half 27-34 20-25 -
Support, Sector 27-34 20-25 -
Nuts, Mounting 30-41 20-30 -
Bolts, Shift Motor and
Mode Sensor Assembly16-25 12-18 -
Nut, Companion Flange 176-271 130-200 -
Fig. 88 Install Companion Flange Nut
1 - HOLDER 6719
2 - BOLTS
DRTRANSFER CASE - NV273 21 - 713
TRANSFER CASE - NV273 (Continued)

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
NEUTRAL, the vehicle speed is too great, or some
other condition outlined (other than a diagnostic fail-
ure that would prevent this shift) elsewhere (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/TRANSFER CASE CONTROL MODULE -
OPERATION) is not met. Note that this flashing will
continue indefinitely until the conditions are eventu-
ally 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 trans-
fer case NEUTRAL, and any of the driver controlla-
ble conditions 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 control-
lable conditions for shifting are not met while the
Neutral button is depressed. This9toggle9type of fea-
ture 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. 96) 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
(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.
(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 operation.
Fig. 96 Shift Motor - Shown Inverted - Typical
1 - SHIFT MOTOR
21 - 720 TRANSFER CASE - NV273DR
SELECTOR SWITCH (Continued)

INSTALLATION
(1) Route the shoulder belt through the slot in the
trim.
(2) Position the trim and seat the attachment clips
fully.
(3) Install the seat belt anchor bolt and tighten to
40 N´m (30 ft. lbs.).
(4) Install the upper c-pillar trim. (Refer to 23 -
BODY/INTERIOR/C-PILLAR UPPER TRIM -
INSTALLATION)
C-PILLAR UPPER TRIM
REMOVAL
(1) Remove the seat belt turning loop. (Refer to 8 -
ELECTRICAL/RESTRAINTS/SEAT BELT TURNING
LOOP ADJUSTER - REMOVAL)
(2) Using a trim stick C-4755 or equivalent,
remove the upper c-pillar trim. (Fig. 11)
INSTALLATION
(1) Position the upper c-pillar trim and seat the
attachment clips fully.
(2) Install the seat belt turning loop. (Refer to 8 -
ELECTRICAL/RESTRAINTS/SEAT BELT TURNING
LOOP ADJUSTER - INSTALLATION)
FLOOR CONSOLE
REMOVAL
(1) Remove the 4WD shifter boot. (Refer to 23 -
BODY/INTERIOR/4WD FLOOR SHIFT BOOT -
REMOVAL)
(2) Using a trim stick C-4755 or equivalent, pry up
the transmission shifter boot from the console.
(3) Remove the transmission shifter extension.
(4) Remove the console inserts. (Fig. 12)
(5) Remove and discard the three bolts. (Fig. 13)
(6) Lift up on the back and remove the console.
INSTALLATION
(1) Position the front of the console up under the
instrument panel.
(2) Lower the back of the console and install three
new screws.
(3) Install the inserts.
(4) Install the transmission shifter extension.
(5) Position the transmission shifter boot in place
and seat the attachment clips fully.
(6) Install the 4WD shifter boot. (Refer to 23 -
BODY/INTERIOR/4WD FLOOR SHIFT BOOT -
INSTALLATION)
Fig. 12 FLOOR CONSOLE INSERTS
1 - BIN PAD INSERT
2 - STORAGE BIN/SHIFT BOOT
3 - CUP HOLDER INSERT
4 - FLOOR CONSOLE
Fig. 13 FLOOR CONSOLE
1 - INSTRUMENT PANEL
2 - FLOOR CONSOLE
3 - BOLTS (3)
4 - SHIFTER LEVER
23 - 68 INTERIORDR
C-PILLAR LOWER TRIM (Continued)