2003 DODGE RAM Speed sensor

(b) Position Gauge Tool 6311 across face of over-
drive case (Fig. 178). Then position Dial Caliper
C-4962 over gauge tool.
(c) Extend sliding scale of dial caliper downward
through gauge tool slot until scale contacts end of
Gauge Alignment Tool 6312. Lock scale in place.
Remove dial caliper tool and note distance mea-
sured (Fig. 178).
(d) Select proper thickness end play spacer from
spacer chart based on distance measured (Fig.
179).
(e) Remove Gauge Alignment Tool 6312.
OD THRUST PLATE SELECTION
(1) Place overdrive unit in vertical position. Mount
it on blocks, or in workbench with appropriate size
mounting hole cut into it. Be sure unit is facingupward for access to direct clutch hub. Also be sure
output shaft is not loaded and internal components
are moved rearward for accurate measurement.
(2) Determine correct thickness overdrive piston
thrust plate as follows:
(a) Position Gauge Tool 6311 across face of over-
drive case. Then position Dial Caliper C-4962 over
gauge tool (Fig. 180).
(b) Measure distance to clutch hub thrust bear-
ing seat at four points 90É apart. Then average
measurements by adding them and dividing by 4.
(c) Select and install required thrust plate from
information in thrust plate chart (Fig. 181).
(3) Leave Alignment Tool 6227-2 in place. Tool will
keep planetary and clutch hub splines in alignment
until overdrive unit is ready for installation on trans-
mission.
(4) Transmission speed sensor can be installed at
this time if desired. However, it is recommended that
sensor not be installed until after overdrive unit is
secured to transmission.
Fig. 177 Overdrive Clutch Pack Retaining Ring
Installation
1 - OVERDRIVE CLUTCH PACK RETAINING RING
Fig. 178 Shaft End Play Measurement
1 - SPECIAL TOOL 6312
2 - SPECIAL TOOL 6311
3 - SPECIAL TOOL C-4962
Fig. 179 Intermediate Shaft End Play Spacer
Selection
Fig. 180 Overdrive Piston Thrust Plate Measurement
1 - SPECIAL TOOL 6311
2 - DIRECT CLUTCH HUB THRUST BEARING SEAT
3 - SPECIAL TOOL C-4962
DRAUTOMATIC TRANSMISSION - 48RE 21 - 413
OVERDRIVE UNIT (Continued)

OVERDRIVE PISTON
(1) Install new seals on overdrive piston.
(2) Stand transmission case upright on bellhous-
ing.
(3) Position Guide Ring 8114-1 on outer edge of
overdrive piston retainer.
(4) Position Seal Guide 8114-3 on inner edge of
overdrive piston retainer.
(5) Install overdrive piston in overdrive piston
retainer by:
(a) Aligning locating lugs on overdrive piston to
the two mating holes in retainer.
(b) Lubricate overdrive piston seals with Mopart
ATF+4.
(c) Install piston over Seal Guide 8114-3 and
inside Guide Ring 8114-1.
(d) Push overdrive piston into position in
retainer.
(e) Verify that the locating lugs entered the lug
bores in the retainer.
(6) Install intermediate shaft spacer on intermedi-
ate shaft.
(7) Install overdrive piston thrust plate on over-
drive piston.
(8) Install overdrive piston thrust bearing on over-
drive piston.
(9) Install transmission speed sensor and o-ring
seal in overdrive case.
INSTALLATION
(1) Be sure overdrive unit Alignment Tool 6227-2
is fully seated before moving unit. If tool is not
seated and gear splines rotate out of alignment, over-
drive unit will have to be disassembled in order to
realign splines.
(2) If overdrive piston retainer was not removed
during service and original case gasket is no longer
reusable, prepare new gasket by trimming it.(3) Cut out old case gasket around piston retainer
with razor knife (Fig. 182).
(4) Use old gasket as template and trim new gas-
ket to fit.
(5) Position new gasket over piston retainer and
on transmission case. Use petroleum jelly to hold
gasket in place if necessary. Do not use any type of
sealer to secure gasket. Use petroleum jelly only.
(6) Install selective spacer on intermediate shaft, if
removed. Spacer goes in groove just rearward of
shaft rear splines (Fig. 183).
(7) Install thrust bearing in overdrive unit sliding
hub. Use petroleum jelly to hold bearing in position.
CAUTION: Be sure the shoulder on the inside diam-
eter of the bearing is facing forward.
(8) Verify that splines in overdrive planetary gear
and overrunning clutch hub are aligned with Align-
Fig. 181 Overdrive Piston Thrust Plate Selection
Fig. 182 Trimming Overdrive Case Gasket
1 - GASKET
2 - SHARP KNIFE
Fig. 183 Intermediate Shaft Selective Spacer
Location
1 - SELECTIVE SPACER
2 - SPACER GROOVE
3 - INTERMEDIATE SHAFT
21 - 414 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)

ment Tool 6227-2. Overdrive unit cannot be installed
if splines are not aligned. If splines have rotated out
of alignment, unit will have to be disassembled to
realign splines.
(9)
Carefully slide Alignment Tool 6227-2 out of over-
drive planetary gear and overrunning clutch splines.
(10) Raise overdrive unit and carefully slide it
straight onto intermediate shaft. Insert park rod into
park lock reaction plug at same time. Avoid tilting
overdrive during installation as this could cause
planetary gear and overrunning clutch splines to
rotate out of alignment. If this occurs, it will be nec-
essary to remove and disassemble overdrive unit to
realign splines.
(11) Work overdrive unit forward on intermediate
shaft until seated against transmission case.
(12) Install bolts attaching overdrive unit to trans-
mission unit. Tighten bolts in diagonal pattern to 34
N´m (25 ft-lbs).
(13) Connect the transmission speed sensor and
overdrive wiring connectors.
(14) Install the transfer case, if equipped.
(15) Align and install rear propeller shaft, if nec-
essary. (Refer to 3 - DIFFERENTIAL & DRIVELINE/
PROPELLER SHAFT/PROPELLER SHAFT -
INSTALLATION)
OVERRUNNING CLUTCH
CAM/OVERDRIVE PISTON
RETAINER
DESCRIPTION
The overrunning clutch (Fig. 184) consists of an
inner race, an outer race (or cam), rollers and
springs, and the spring retainer. The number of roll-
ers and springs depends on what transmission and
which overrunning clutch is being dealt with.
OPERATION
As the inner race is rotated in a clockwise direction
(as viewed from the front of the transmission), the
race causes the rollers to roll toward the springs,
causing them to compress against their retainer. The
compression of the springs increases the clearance
between the rollers and cam. This increased clear-
ance between the rollers and cam results in a free-
wheeling condition. When the inner race attempts to
rotate counterclockwise, the action causes the rollers
to roll in the same direction as the race, aided by the
pushing of the springs. As the rollers try to move in
the same direction as the inner race, they are
wedged between the inner and outer races due to the
design of the cam. In this condition, the clutch is
locked and acts as one unit.
DISASSEMBLY
(1) Remove the overdrive piston (Fig. 185).
(2) Remove the overdrive piston retainer bolts.
(3) Remove overdrive piston retainer.
(4) Remove case gasket.
Fig. 185 Overdrive Piston Removal
1 - OVERDRIVE CLUTCH PISTON
2 - INTERMEDIATE SHAFT
3 - SELECTIVE SPACER
4 - PISTON RETAINER
Fig. 184 Overrunning Clutch
1 - OUTER RACE (CAM)
2 - ROLLER
3 - SPRING
4 - SPRING RETAINER
5 - INNER RACE (HUB)
DRAUTOMATIC TRANSMISSION - 48RE 21 - 415
OVERDRIVE UNIT (Continued)

SOLENOID
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.
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 voltageacross 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.
SPEED SENSOR
DESCRIPTION
The speed sensor (Fig. 227) is located in the over-
drive gear case. The sensor is positioned over the
park gear and monitors transmission output shaft
rotating speed.
OPERATION
Speed sensor signals are triggered by the park
gear lugs as they rotate past the sensor pickup face.
Input signals from the sensor are sent to the trans-
mission control module for processing. Signals from
this sensor are shared with the powertrain control
module.
Fig. 227 Transmission Output Speed Sensor
1 - TRANSMISSION OUTPUT SHAFT SPEED SENSOR
2 - SEAL
DRAUTOMATIC TRANSMISSION - 48RE 21 - 431

AUTOMATIC TRANSMISSION - 45RFE/545RFE
TABLE OF CONTENTS
page page
AUTOMATIC TRANSMISSION - 45RFE/545RFE
DESCRIPTION........................489
OPERATION..........................490
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION.....................491
DIAGNOSIS AND TESTING - PRELIMINARY. . 491
DIAGNOSIS AND TESTING - ROAD
TESTING...........................491
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TEST....................493
DIAGNOSIS AND TESTING - AIR CHECKING
TRANSMISSION CLUTCH OPERATION....494
DIAGNOSIS AND TESTING - CONVERTER
HOUSING FLUID LEAK................495
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR.....................495
REMOVAL............................495
DISASSEMBLY........................497
CLEANING...........................502
INSPECTION.........................503
ASSEMBLY...........................503
INSTALLATION........................510
SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS.............513
SPECIFICATIONS
TRANSMISSION.....................534
SPECIAL TOOLS
RFE TRANSMISSION.................535
4C RETAINER/BULKHEAD
DISASSEMBLY........................538
ASSEMBLY...........................538
ADAPTER HOUSING SEAL
REMOVAL............................539
INSTALLATION........................539
BRAKE TRANSMISSION SHIFT INTERLOCK
SYSTEM
DESCRIPTION........................540
OPERATION..........................540
DIAGNOSIS AND TESTING - BRAKE
TRANSMISSION SHIFT INTERLOCK......540
ADJUSTMENTS - BRAKE TRANSMISSION
SHIFT INTERLOCK...................540
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL.............541
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID.......................541DIAGNOSIS AND TESTING - FLUID
CONTAMINATION....................541
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK............................542
STANDARD PROCEDURE - FLUID AND
FILTER REPLACEMENT...............542
STANDARD PROCEDURE - TRANSMISSION
FILL...............................544
GEARSHIFT CABLE
DIAGNOSIS AND TESTING - GEARSHIFT
CABLE.............................544
REMOVAL............................544
INSTALLATION........................545
ADJUSTMENTS
GEARSHIFT CABLE..................546
HOLDING CLUTCHES
DESCRIPTION........................546
OPERATION..........................546
INPUT CLUTCH ASSEMBLY
DESCRIPTION........................549
OPERATION..........................549
DISASSEMBLY........................550
ASSEMBLY...........................552
INPUT SPEED SENSOR
DESCRIPTION........................558
OPERATION..........................558
REMOVAL............................559
INSTALLATION........................559
LINE PRESSURE (LP) SENSOR
DESCRIPTION........................559
OPERATION..........................559
REMOVAL............................559
INSTALLATION........................560
LOW/REVERSE CLUTCH
DISASSEMBLY........................560
CLEANING...........................561
INSPECTION.........................561
ASSEMBLY...........................561
OIL PUMP
DESCRIPTION........................562
OPERATION..........................562
STANDARD PROCEDURE - OIL PUMP
VOLUME CHECK.....................563
DISASSEMBLY........................564
CLEANING...........................566
INSPECTION.........................566
ASSEMBLY...........................566
21 - 488 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR

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

The label gives additional information which may
also be necessary for identification purposes.
GEAR RATIOS
The 45RFE gear ratios are:
1st .................................3.00:1
2nd.................................1.67:1
2nd Prime...........................1.50:1
3rd.................................1.00:1
4th .................................0.75:1
Reverse.............................3.00:1
GEAR RATIOS
The 545RFE gear ratios are:
1st .................................3.00:1
2nd.................................1.67:1
2nd Prime...........................1.50:1
3rd.................................1.00:1
4th .................................0.75:1
5th .................................0.67:1
Reverse.............................3.00:1
OPERATION
The 45RFE/545RFE offers full electronic control of
all automatic up and downshifts, and features real-
time adaptive closed-loop shift and pressure control.
Electronic shift and torque converter clutch controls
help protect the transmission from damage due to
high temperatures, which can occur under severe
operating conditions. By altering shift schedules, line
pressure, and converter clutch control, these controls
reduce heat generation and increase transmission
cooling.
To help reduce efficiency-robbing parasitic losses,
the transmissions includes a dual-stage transmission
fluid pump with electronic output pressure control.
Under most driving conditions, pump output pres-
sure greatly exceeds that which is needed to keep the
clutches applied. The 45RFE/545RFE pump-pressure
control system monitors input torque and adjusts the
pump pressure accordingly. The primary stage of the
pump works continuously; the second stage is
bypassed when demand is low. The control system
also monitors input and output speed and, if incipi-
ent clutch slip is observed, the pressure control sole-
noid duty cycle is varied, increasing pressure in
proportion to demand.
A high-travel torque converter damper assembly
allows earlier torque converter clutch engagement to
reduce slippage. Needle-type thrust bearings reduce
internal friction. The 45RFE/545RFE is packaged in
a one-piece die-cast aluminum case. To reduce NVH,
the case has high lateral, vertical and torsional stiff-
ness. It is also designed to maximize the benefit of
the structural dust cover that connects the bottom of
the bell housing to the engine bedplate, enhancing
overall power train stiffness. Dual filters protect the
pump and other components. A pump return filter is
added to the customary main sump filter. Indepen-
dent lubrication and cooler circuits assure ample
pressure for normal transmission operation even if
the cooler is obstructed or the fluid cannot flow due
to extremely low temperatures.
The hydraulic control system design (without elec-
tronic assist) provides the transmission with PARK,
REVERSE, NEUTRAL, SECOND, and THIRD gears,
based solely on driver shift lever selection. This
design allows the vehicle to be driven (in ªlimp-inº
mode) in the event of a electronic control system fail-
ure, or a situation that the Transmission Control
Module (TCM) recognizes as potentially damaging to
the transmission.
The TCM also performs certain self-diagnostic
functions and provides comprehensive information
(sensor data, DTC's, etc.) which is helpful in proper
diagnosis and repair. This information can be viewed
with the DRBtscan tool.
Fig. 1 Transmission Part And Serial Number
Location
1 - IDENTIFICATION NUMBERS (STAMPED)
21 - 490 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

(9) Disconnect and lower or remove any necessary
exhaust components.
(10) Remove the starter motor.
(11) Rotate crankshaft in clockwise direction until
converter bolts are accessible. Then remove bolts one
at a time. Rotate crankshaft with socket wrench on
dampener bolt.
(12) Disengage the output speed sensor connector
from the output speed sensor (Fig. 9).
(13) Disengage the input speed sensor connector
from the input speed sensor (Fig. 10).(14) Disengage the transmission solenoid/TRS
assembly connector from the transmission solenoid/
TRS assembly (Fig. 11).
(15) Disengage the line pressure sensor connector
from the line pressure sensor (Fig. 12).
Fig. 9 Disconnect Output Speed Sensor
1 - TRANSMISSION
2 - OUTPUT SPEED SENSOR
Fig. 10 Disconnect Input Speed Sensor
1 - TRANSMISSION
2 - INPUT SPEED SENSOR
Fig. 11 Disconnect Transmission Solenoid/TRS
Assembly
1 - TRANSMISSION
2 - TRANSMISSION SOLENOID/TRS ASSEMBLY
Fig. 12 Disconnect Line Pressure Sensor
1 - TRANSMISSION
2 - LINE PRESSURE SENSOR
21 - 496 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)