ESP DODGE RAM 2003 Service Owners Manual
[x] Cancel search | Manufacturer: DODGE, Model Year: 2003, Model line: RAM, Model: DODGE RAM 2003Pages: 2895, PDF Size: 83.15 MB
Page 2328 of 2895

OIL PUMP FRONT SEAL
REMOVAL............................567
INSTALLATION........................567
OUTPUT SPEED SENSOR
DESCRIPTION........................567
OPERATION..........................567
REMOVAL............................567
INSTALLATION........................567
OVERDRIVE SWITCH
DESCRIPTION........................568
OPERATION..........................568
REMOVAL............................568
INSTALLATION........................569
PISTONS
DESCRIPTION........................569
OPERATION..........................569
PLANETARY GEARTRAIN
DESCRIPTION........................571
OPERATION..........................571
DISASSEMBLY........................573
CLEANING...........................573
INSPECTION.........................573
ASSEMBLY...........................573
SHIFT MECHANISM
DESCRIPTION........................574
OPERATION..........................574
SOLENOID SWITCH VALVE
DESCRIPTION........................574
OPERATION..........................574
SOLENOIDS
DESCRIPTION........................574OPERATION..........................575
TORQUE CONVERTER
DESCRIPTION........................575
OPERATION..........................579
REMOVAL............................580
INSTALLATION........................580
TRANSMISSION CONTROL RELAY
DESCRIPTION........................581
OPERATION..........................581
TRANSMISSION RANGE SENSOR
DESCRIPTION........................581
OPERATION..........................581
TRANSMISSION SOLENOID/TRS ASSEMBLY
DESCRIPTION........................582
OPERATION..........................582
REMOVAL............................583
INSTALLATION........................583
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION........................583
OPERATION..........................583
VALVE BODY
DESCRIPTION........................584
OPERATION..........................585
REMOVAL............................585
DISASSEMBLY........................586
CLEANING...........................588
INSPECTION.........................588
ASSEMBLY...........................590
INSTALLATION........................590
AUTOMATIC TRANSMISSION -
45RFE/545RFE
DESCRIPTION
The 45RFE/545RFE automatic transmissions is a
sophisticated, multi-range, electronically controlled
transmission which combines optimized gear ratios
for responsive performance, state of the art efficiency
features and low NVH. Other features include driver
adaptive shifting and three planetary gear sets to
provide wide ratio capability with precise ratio steps
for optimum driveability. The three planetary gear
sets also make available a unique alternate second
gear ratio. The primary 2nd gear ratio fits between
1st and 3rd gears for normal through-gear accelera-
tions. The alternate second gear ratio (2prime) allows
smoother 4-2 kickdowns at high speeds to provide
2nd gear passing performance over a wider highway
cruising range.
The hydraulic portion of the transmission consists
of the transmission fluid, fluid passages, hydraulic
valves, and various line pressure control components.The primary mechanical components of the trans-
mission consist of the following:
²Three multiple disc input clutches
²Three multiple disc holding clutches
²Five hydraulic accumulators
²Three planetary gear sets
²Dual Stage Hydraulic oil pump
²Valve body
²Solenoid pack
The TCM is the ªheartº or ªbrainº of the electronic
control system and relies on information from vari-
ous direct and indirect inputs (sensors, switches, etc.)
to determine driver demand and vehicle operating
conditions. With this information, the TCM can cal-
culate and perform timely and quality shifts through
various output or control devices (solenoid pack,
transmission control relay, etc.).
TRANSMISSION IDENTIFICATION
Transmission identification numbers are stamped
on the left side of the case just above the oil pan
sealing surface (Fig. 1). Refer to this information
when ordering replacement parts. A label is attached
to the transmission case above the stamped numbers.
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 489
Page 2388 of 2895

INPUT CLUTCH ASSEMBLY
DESCRIPTION
Three hydraulically applied input clutches are used
to drive planetary components. The underdrive, over-
drive, and reverse clutches are considered input
clutches and are contained within the input clutch
assembly (Fig. 77) and (Fig. 78). The input clutch
assembly also contains:
²Input shaft
²Input hub
²Clutch retainer
²Underdrive piston
²Overdrive/reverse piston²Overdrive hub
²Underdrive hubOPERATION
The three input clutches are responsible for driving
different components of the planetary geartrain.
UNDERDRIVE CLUTCH
The underdrive clutch is hydraulically applied in
first, second, second prime, and third (direct) gears
by pressurized fluid against the underdrive piston.
When the underdrive clutch is applied, the under-
drive hub drives the input sun gear.
Fig. 77 Input Clutch Assembly - Part 1
1 - INPUT CLUTCH HUB 11 - UD CLUTCH
2 - O-RING SEALS 12 - PLATE
3 - SEAL 13 - CLUTCH RETAINER
4 - SNAP-RING 14 - SEAL
5 - SNAP-RING 15 - OD/REV PISTON
6 - UD BALANCE PISTON 16 - BELLEVILLE SPRING
7 - SNAP-RING 17 - SNAP-RING
8 - UD PISTON 18 - SEAL RINGS
9 - SPRING 19 - INPUT SHAFT
10 - DISC 20 - LUBRICATION CHECK VALVE AND SNAP-RING
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 549
Page 2413 of 2895

(5) Install the number 9 bearing onto the front of
the reverse planetary carrier with the outer race
toward the carrier and the inner race facing upward
(Fig. 116).
(6) Install the reverse planetary gear carrier into
the input carrier (Fig. 116).
(7) Install the input annulus gear into the input
carrier (Fig. 116).
(8) Install the snap-ring to hold the input annulus
gear into the input carrier (Fig. 116).
SHIFT MECHANISM
DESCRIPTION
The gear shift mechanism provides six shift posi-
tions which are:
²Park (P)
²Reverse (R)
²Neutral (N)
²Drive (D)
²Manual second (2)
²Manual low (1)
OPERATION
MANUAL LOW (1) range provides first gear only.
Overrun braking is also provided in this range.
MANUAL SECOND (2) range provides first and sec-
ond gear only.
DRIVE range provides FIRST, SECOND, THIRD,
OVERDRIVE FOURTH, and OVERDRIVE FIFTH (if
applicable) gear ranges. The shift into OVERDRIVE
FOURTH and FIFTH (if applicable) gear ranges
occurs only after the transmission has completed the
shift into D THIRD gear range. No further movement
of the shift mechanism is required to complete the
3-4 or 4-5 (if applicable) shifts.
The FOURTH and FIFTH (if applicable) gear
upshifts occur automatically when the overdrive
selector switch is in the ON position. No upshift to
FOURTH or FIFTH (if applicable) gears will occur if
any of the following are true:
²The transmission fluid temperature is below 10É
C (50É F) or above 121É C (250É F).
²The shift to THIRD is not yet complete.
²Vehicle speed is too low for the 3-4 or 4-5 (if
applicable) shifts to occur.
Upshifts into FOURTH or FIFTH (if applicable)
will be delayed when the transmission fluid temper-
ature is below 4.5É C (40É F) or above 115.5É C (240É
F).
SOLENOID SWITCH VALVE
DESCRIPTION
The Solenoid Switch Valve (SSV) is located in the
valve body and controls the direction of the transmis-
sion fluid when the L/R-TCC solenoid is energized.
OPERATION
The Solenoid Switch Valve controls line pressure
from the LR-TCC solenoid. In 1st gear, the SSV will
be in the downshifted position, thus directing fluid to
the L/R clutch circuit. In 2nd, 3rd, 4th, and 5th (if
applicable) gears, the solenoid switch valve will be in
the upshifted position and directs the fluid into the
torque converter clutch (TCC) circuit.
When shifting into 1st gear, a special hydraulic
sequence is performed to ensure SSV movement into
the downshifted position. The L/R pressure switch is
monitored to confirm SSV movement. If the move-
ment is not confirmed (the L/R pressure switch does
not close), 2nd gear is substituted for 1st. A DTC will
be set after three unsuccessful attempts are made to
get into 1st gear in one given key start.
SOLENOIDS
DESCRIPTION
The typical electrical solenoid used in automotive
applications is a linear actuator. It is a device that
produces motion in a straight line. This straight line
motion can be either forward or backward in direc-
tion, and short or long distance.
A solenoid is an electromechanical device that uses
a magnetic force to perform work. It consists of a coil
of wire, wrapped around a magnetic core made from
steel or iron, and a spring loaded, movable plunger,
which performs the work, or straight line motion.
The solenoids used in transmission applications
are attached to valves which can be classified asnor-
mally openornormally closed. Thenormally
opensolenoid valve is defined as a valve which
allows hydraulic flow when no current or voltage is
applied to the solenoid. Thenormally closedsole-
noid valve is defined as a valve which does not allow
hydraulic flow when no current or voltage is applied
to the solenoid. These valves perform hydraulic con-
trol functions for the transmission and must there-
fore be durable and tolerant of dirt particles. For
these reasons, the valves have hardened steel pop-
pets and ball valves. The solenoids operate the valves
directly, which means that the solenoids must have
very high outputs to close the valves against the siz-
able flow areas and line pressures found in current
transmissions. Fast response time is also necessary
to ensure accurate control of the transmission.
21 - 574 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
PLANETARY GEARTRAIN (Continued)
Page 2414 of 2895

The strength of the magnetic field is the primary
force that determines the speed of operation in a par-
ticular solenoid design. A stronger magnetic field will
cause the plunger to move at a greater speed than a
weaker one. There are basically two ways to increase
the force of the magnetic field:
1. Increase the amount of current applied to the
coil or
2. Increase the number of turns of wire in the coil.
The most common practice is to increase the num-
ber of turns by using thin wire that can completely
fill the available space within the solenoid housing.
The strength of the spring and the length of the
plunger also contribute to the response speed possi-
ble by a particular solenoid design.
A solenoid can also be described by the method by
which it is controlled. Some of the possibilities
include variable force, pulse-width modulated, con-
stant ON, or duty cycle. The variable force and pulse-
width modulated versions utilize similar methods to
control the current flow through the solenoid to posi-
tion the solenoid plunger at a desired position some-
where between full ON and full OFF. The constant
ON and duty cycled versions control the voltage
across the solenoid to allow either full flow or no flow
through the solenoid's valve.
OPERATION
When an electrical current is applied to the sole-
noid coil, a magnetic field is created which produces
an attraction to the plunger, causing the plunger to
move and work against the spring pressure and the
load applied by the fluid the valve is controlling. The
plunger is normally directly attached to the valve
which it is to operate. When the current is removed
from the coil, the attraction is removed and the
plunger will return to its original position due to
spring pressure.
The plunger is made of a conductive material and
accomplishes this movement by providing a path for
the magnetic field to flow. By keeping the air gap
between the plunger and the coil to the minimum
necessary to allow free movement of the plunger, the
magnetic field is maximized.
TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 117) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine, a stator, an
overrunning clutch, an impeller and an electronically
applied converter clutch. The converter clutch pro-
vides reduced engine speed and greater fuel economy
when engaged. Clutch engagement also provides
reduced transmission fluid temperatures. The torque
converter hub drives the transmission oil (fluid)
pump and contains an o-ring seal to better control oil
flow.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
CAUTION: The torque converter must be replaced if
a transmission failure resulted in large amounts of
metal or fiber contamination in the fluid.
Fig. 117 Torque Converter Assembly
1 - TURBINE ASSEMBLY
2-STATOR
3 - CONVERTER HUB
4 - O-RING
5 - IMPELLER ASSEMBLY
6 - CONVERTER CLUTCH PISTON
7 - TURBINE HUB
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 575
SOLENOIDS (Continued)
Page 2441 of 2895

(3) Remove front tabbed thrust washer (Fig. 37).
(4) Remove input gear (Fig. 38).
(5) Remove rear tabbed thrust washer from low
range gear (Fig. 39).
CLEANING
Clean the transfer case parts with a standard
parts cleaning solvent. Remove all traces of sealer
from the cases and retainers with a scraper and
3MŸ all purpose cleaner. Use compressed air to
remove solvent residue from oil feed passages in the
case halves, retainers, gears, and shafts.
INSPECTION
MAINSHAFT/SPROCKET/HUB
Inspect the splines on the hub and shaft and the
teeth on the sprocket. Minor nicks and scratches can
be smoothed with an oilstone, however, replace any
part that is damaged.
Check the contact surfaces in the sprocket bore
and on the mainshaft. Minor nicks and scratches can
be smoothed with 320-400 grit emery cloth but do not
try to salvage the shaft if nicks or wear is severe.
INPUT GEAR AND PLANETARY CARRIER
Check the teeth on the gear (Fig. 40). Minor nicks
can be dressed off with an oilstone but replace the
gear if any teeth are broken, cracked, or chipped. The
bearing surface on the gear can be smoothed with
300-400 grit emery cloth if necessary.
Examine the carrier body and pinion gears for
wear or damage. The carrier will have to be replaced
as an assembly if the body, pinion pins, or pinion
gears are damaged.
Check the lock ring and both thrust washers for
wear or cracks. Replace them if necessary. Also
replace the lock retaining ring if bent, distorted, or
broken.
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork
shift rail (Fig. 41). Minor nicks on the shift rail can
be smoothed with 320-400 grit emery cloth.
Inspect the shift fork wear pads (Fig. 42). The
mode fork pads are serviceable and can be replaced if
necessary. The range fork pads are not serviceable.
The fork must be replaced as an assembly if the pads
are worn or damaged.
Check both of the sleeves for wear or damage,
especially on the interior teeth. Replace the sleeves if
wear or damage is evident.
Fig. 37 Front Tabbed Thrust Washer Removal
1 - FRONT TABBED THRUST WASHER
Fig. 38 Input Gear Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
Fig. 39 Rear Tabbed Thrust Washer Removal
1 - LOW RANGE GEAR
2 - REAR TABBED THRUST WASHER
21 - 602 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)
Page 2475 of 2895

Examine the carrier body and pinion gears for
wear or damage. Check the pinion gear thrust wash-
ers on the pinon pins for damage. The carrier will
have to be replaced as an assembly if the body, pin-
ion pins, or pinion gears are damaged.
Check the lock ring and both thrust washers for
wear or cracks. Replace them if necessary. Also
replace the lock retaining ring if bent, distorted, or
broken.
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork
shift rail (Fig. 41). Minor nicks on the shift rail can
be smoothed with 320-400 grit emery cloth.
Inspect the shift fork wear pads (Fig. 42). The
mode and range fork pads are serviceable and can be
replaced if necessary.
Check both of the sleeves for wear or damage,
especially on the interior teeth. Replace the sleeves if
wear or damage is evident.
DRIVE CHAIN
Examine the drive chain and shaft bearings.
replace the chain if stretched, distorted, or if any of
the links bind. Replace the bearings if rough, or
noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear condition carefully. The gear
is only serviced as part of the front case. If the gear
is damaged, it will be necessary to replace the gear
and front case as an assembly. Do not attempt to
remove the gear (Fig. 43)
FRONT CASE AND REAR CASE
Inspect the cases for wear and damage.Check case condition. If leaks were a problem, look
for gouges and severe scoring of case sealing sur-
faces. Also make sure the front case mounting studs
are in good condition.
Check the front case mounting studs and vent
tube. The tube can be secured with LoctiteŸ 271 or
680 if loose. The stud threads can be cleaned up with
a die if necessary. Also check condition of the fill/
drain plug threads in the rear case. The threads can
be repaired with a thread chaser or tap if necessary.
Or the threads can be repaired with HelicoilŸ stain-
less steel inserts if required.
OIL PUMP/OIL PICKUP
Examine the oil pump pickup parts. Replace the
pump if any part appears to be worn or damaged. Do
Fig. 41 Shift forks
1 - RANGE FORK
2 - MODE FORK AND RAIL
3 - MODE SPRING
Fig. 42 Shift Fork And Wear Pad Locations
1 - RANGE FORK
2 - MODE FORK
3 - WEAR PADS (SERVICEABLE)
4 - WEAR PADS (SERVICEABLE)
Fig. 43 Low Range Annulus Gear
1 - FRONT CASE
2 - LOW RANGE ANNULUS GEAR
21 - 636 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)
Page 2509 of 2895

Inspect the shift fork wear pads (Fig. 41). The
mode and range fork pads are serviceable and can be
replaced if necessary.
Check both of the sleeves for wear or damage,
especially on the interior teeth. Replace the sleeves if
wear or damage is evident.
REAR EXTENSION HOUSING
Inspect the extension housing seal and bushing.
Replace both components if either show any sign of
wear or damage.
FRONT OUTPUT SHAFT AND DRIVE CHAIN
Inspect the shaft threads, sprocket teeth, and bear-
ing surfaces. Minor nicks on the teeth can be
smoothed with an oilstone. Use 320-400 grit emery to
smooth minor scratches on the shaft bearing sur-
faces. Rough threads on the shaft can be chased if
necessary. Replace the shaft if the threads are dam-
aged, bearing surfaces are scored, or if any sprocket
teeth are cracked or broken.
Examine the drive chain and shaft bearings.
Replace the chain and both sprockets if the chain is
stretched, distorted, or if any of the links bind.
Replace the bearings if rough, or noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear condition carefully. The gear
is only serviced as part of the front case. If the gear
is damaged, it will be necessary to replace the gear
and front case as an assembly. Do not attempt to
remove the gear (Fig. 42)
FRONT AND REAR CASES
Inspect the cases for wear and damage.Check case condition. If leaks were a problem, look
for gouges and severe scoring of case sealing sur-
faces. Also make sure the front case mounting studs
are in good condition.
Check the front case mounting studs and vent
tube. The tube can be secured with LoctiteŸ 271 or
680 if loose. The stud threads can be cleaned up with
a die if necessary. Also check condition of the fill/
drain plug threads in the rear case. The threads can
be repaired with a thread chaser or tap if necessary.
Or the threads can be repaired with Helicoiltstain-
less steel inserts if required.
OIL PUMP/OIL PICKUP
Examine the oil pump pickup parts. Replace the
pump if any part appears to be worn or damaged. Do
not disassemble the pump as individual parts are not
available. The pump is only available as a complete
assembly. The pickup screen, hose, and tube are the
only serviceable parts and are available separately.
ASSEMBLY
BEARINGS AND SEALS
(1) Remove the input shaft bearing (Fig. 43) from
the front case with suitable snap-ring pliers.
(2) Transfer the retaining ring to the new bearing
if necessary and install the bearing into the front
case.
(3) Using Installer 6436 and Handle C-4171 (Fig.
44), remove front output shaft bearing.
(4) Start front output shaft bearing in case. Then
seat bearing with Handle C-4171 and Installer 6953.
(5) Install front output shaft bearing retaining
ring.
Fig. 41 Shift Fork And Wear Pad Locations
1 - RANGE FORK
2 - MODE FORK
3 - WEAR PADS (SERVICEABLE)
4 - WEAR PADS (SERVICEABLE)
Fig. 42 Low Range Annulus Gear
1 - FRONT CASE
2 - LOW RANGE ANNULUS GEAR
21 - 670 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)
Page 2525 of 2895

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. 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
(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 opera-
tion.
Fig. 85 Shift Motor - Shown Inverted - Typical
1 - SHIFT MOTOR
21 - 686 TRANSFER CASE - NV243DR
SELECTOR SWITCH (Continued)
Page 2539 of 2895

SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork
shift rail (Fig. 40). Minor nicks on the shift rail can
be smoothed with 320-400 grit emery cloth.
Inspect the shift fork wear pads (Fig. 41). The
mode and range fork pads are serviceable and can be
replaced if necessary.
Check both of the sleeves for wear or damage,
especially on the interior teeth. Replace the sleeves if
wear or damage is evident.
REAR EXTENSION HOUSING
Inspect the extension housing seal and bushing.
Replace both components if either show any sign of
wear or damage.
FRONT OUTPUT SHAFT AND DRIVE CHAIN
Inspect the shaft threads, sprocket teeth, and bear-
ing surfaces. Minor nicks on the teeth can be
smoothed with an oilstone. Use 320-400 grit emery to
smooth minor scratches on the shaft bearing sur-
faces. Rough threads on the shaft can be chased if
necessary. Replace the shaft if the threads are dam-
aged, bearing surfaces are scored, or if any sprocket
teeth are cracked or broken.
Examine the drive chain and shaft bearings.
Replace the chain and both sprockets if the chain is
stretched, distorted, or if any of the links bind.
Replace the bearings if rough, or noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear condition carefully. The gear
is only serviced as part of the front case. If the gear
is damaged, it will be necessary to replace the gear
and front case as an assembly. Do not attempt to
remove the gear (Fig. 42)
FRONT AND REAR CASES
Inspect the cases for wear and damage.
Check case condition. If leaks were a problem, look
for gouges and severe scoring of case sealing sur-
faces. Also make sure the front case mounting studs
are in good condition.
Check the front case mounting studs and vent
tube. The tube can be secured with LoctiteŸ 271 or
680 if loose. The stud threads can be cleaned up with
a die if necessary. Also check condition of the fill/
drain plug threads in the rear case. The threads can
Fig. 40 Shift Forks
1 - RANGE FORK
2 - MODE FORK AND RAIL
3 - MODE SPRING
Fig. 41 Shift Fork And Wear Pad Locations
1 - RANGE FORK
2 - MODE FORK
3 - WEAR PADS (SERVICEABLE)
4 - WEAR PADS (SERVICEABLE)
Fig. 42 Low Range Annulus Gear
1 - FRONT CASE
2 - LOW RANGE ANNULUS GEAR
21 - 700 TRANSFER CASE - NV273DR
TRANSFER CASE - NV273 (Continued)
Page 2559 of 2895

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)