1998 DODGE RAM 1500 Speed sensor

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.
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)
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 313
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

(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
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 319
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

(16) Disconnect gearshift cable from transmission
manual valve lever (Fig. 13).
(17) Disconnect the transmission vent hose from
the transmission.
(18) Support rear of engine with safety stand or
jack.
(19) Raise transmission slightly with service jack
to relieve load on crossmember and supports.
(20) Remove bolts securing rear support and cush-
ion to transmission and crossmember.
(21) Remove transfer case, if necessary.
(22) Disconnect transmission fluid cooler lines at
transmission fittings and clips.
(23) Remove all remaining converter housing bolts.
(24) Carefully work transmission and torque con-
verter assembly rearward off engine block dowels.
(25) Hold torque converter in place during trans-
mission removal.
(26) Lower transmission and remove (Fig. 14)
assembly from under the vehicle.
(27) To remove torque converter, carefully slide
torque converter out of the transmission.
DISASSEMBLY
(1) Drain fluid from transmission.
(2) Clean exterior of transmission with suitable
solvent or pressure washer.
(3) Remove the torque converter from the trans-
mission.
(4) Remove the manual shift lever from the trans-
mission.
(5) Remove the input, output, and line pressure
sensors from the transmission case (Fig. 15).
Fig. 13 Gearshift Cable at Transmission - RFE
1 - GEARSHIFT CABLE
2 - RFE TRANSMISSION
3 - MANUAL LEVER
Fig. 14 Remove Transmission
1 - ENGINE
2 - TRANSMISSION
Fig. 15 Remove Input, Output, and Line Pressure
Sensors
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
21 - 320 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

visual inspection through the input speed sensor
hole. If the tone wheel teeth on the input clutch
assembly are centered in the hole, the assembly is
fully installed.
(42) Install the number 1 bearing with the outer
race up in the pocket of the input clutch assembly
(Fig. 45).
(43) Install the oil pump into the transmission
case (Fig. 46).
(44) Install the bolts to hold the oil pump into the
transmission case. Tighten the oil pump bolts to 28
N´m (250 in.lbs.).
(45) Using Adapter 8266-1 from End-Play Tool Set
8266 and Dial Indicator C-3339, measure and record
the input shaft end-play (Fig. 47). The correct end-
play is 0.46-0.89 mm (0.018-0.035 in.). Adjust as nec-
essary. Install the chosen thrust plate on the number
5 bearing and re-measure end-play to verify selec-
tion.
NOTE: When measuring the input shaft end-play,
two(stops(will be felt. When the input shaft is
pushed inward and the dial indicator zeroed, the
first(stop(felt when the input shaft is pulled out-
ward is the movement of the input shaft in the input
clutch housing hub. This value should not be
included in the end-play measured value and there-
fore must be recorded and subtracted from the dial
indicator reading.
Fig. 45 Install Input Clutch Assembly
1 - BEARING NUMBER 5
2 - THRUST PLATE (SELECT)
3 - INPUT CLUTCH ASSEMBLY
4 - BEARING NUMBER 1
Fig. 46 Install Oil Pump
1 - OIL PUMP TO CASE BOLT (6)
2 - OIL PUMP
Fig. 47 Measure Input Shaft End Play
1 - TOOL 8266
2 - TOOL C-3339
21 - 332 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

o-ring is properly installed and is free of any debris.
The hub must be smooth to avoid damaging pump
seal at installation.
(2) If a replacement transmission is being
installed, transfer any components necessary, such as
the manual shift lever and shift cable bracket, from
the original transmission onto the replacement trans-
mission.
(3) Lubricate oil pump seal lip with transmission
fluid.
(4) Align converter and oil pump.(5) Carefully insert converter in oil pump. Then
rotate converter back and forth until fully seated in
pump gears.
(6) Check converter seating with steel scale and
straightedge (Fig. 53). Surface of converter lugs
should be at least 13mm (1/2 in.) to rear of straight-
edge when converter is fully seated.
(7) Temporarily secure converter with C-clamp.
(8) Position transmission on jack and secure it
with chains.
(9) Check condition of converter driveplate.
Replace the plate if cracked, distorted or damaged.
Also be sure transmission dowel pins are seated
in engine block and protrude far enough to
hold transmission in alignment.
(10) Apply a light coating of MopartHigh Temp
Grease to the torque converter hub pocket in the rear
pocket of the engine's crankshaft.
(11) Raise transmission (Fig. 54) and align the
torque converter with the drive plate and transmis-
sion converter housing with the engine block.
(12) Move transmission forward. Then raise, lower
or tilt transmission to align the converter housing
with engine block dowels.
(13) Carefully work transmission forward and over
engine block dowels until converter hub is seated in
crankshaft. Verify that no wires, or the transmission
vent hose, have become trapped between the engine
block and the transmission.
(14) Install two bolts to attach the transmission to
the engine.
(15) Install remaining torque converter housing to
engine bolts. Tighten to 68 N´m (50 ft.lbs.).
Fig. 51 Install Primary Oil and Cooler Filters
1 - PRIMARY OIL FILTER
2 - COOLER RETURN FILTER
3 - COOLER RETURN FILTER BYPASS VALVE
4 - VALVE BODY
Fig. 52 Install Input, Output, and Line Pressure
Sensors
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
Fig. 53 Checking Torque Converter Seating - Typical
1 - SCALE
2 - STRAIGHTEDGE
21 - 334 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

(16) Install transfer case, if equipped. Tighten
transfer case nuts to 35 N´m (26 ft.lbs.).
(17) Install rear support to transmission. Tighten
bolts to 47 N´m (35 ft.lbs.).
(18) Lower transmission onto crossmember and
install bolts attaching transmission mount to cross-
member. Tighten clevis bracket to crossmember bolts
to 47 N´m (35 ft.lbs.). Tighten the clevis bracket to
rear support bolt to 68 N´m (50 ft.lbs.).
(19) Remove engine support fixture.
(20) Connect gearshift cable to transmission.
(21) Connect wires to solenoid and pressure switch
assembly (Fig. 55) connector, input (Fig. 56) and out-
put (Fig. 57) speed sensors, and line pressure sensor
(Fig. 58). Be sure transmission harnesses are prop-
erly routed.
CAUTION: It is essential that correct length bolts be
used to attach the converter to the driveplate. Bolts
that are too long will damage the clutch surface
inside the converter.
Fig. 54 Install Transmission
1 - ENGINE
2 - TRANSMISSION
Fig. 55 Connect Transmission Solenoid
1 - TRANSMISSION
2 - TRANSMISSION SOLENOID/TRS ASSEMBLY
Fig. 56 Connect Input Speed Sensor
1 - TRANSMISSION
2 - INPUT SPEED SENSOR
Fig. 57 Connect Output Speed Sensor
1 - TRANSMISSION
2 - OUTPUT SPEED SENSOR
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 335
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

SPECIFICATIONS
TRANSMISSION
GENERAL
Component Metric Inch
Output Shaft End Play 0.22-0.55
mm0.009-0.021
in.
Input Shaft End Play 0.46-0.89
mm0.018-0.035
in.
2C Clutch Pack
Clearance0.455-1.335
mm0.018-0.053
in.
4C Clutch Pack
Clearance0.770-1.390
mm0.030-0.055
in.
L/R Clutch Pack
Clearance1.00-1.74
mm0.039-0.069
in.
OD Clutch Pack
Clearance1.103-1.856
mm0.043-0.073
in.
Component Metric Inch
UD Clutch Pack
Clearance0.84-1.54
mm0.033-0.061
in.
Reverse Clutch Pack
Clearance0.81-1.24
mm0.032-0.049
in.
Recommended fluid MoparTAT F + 4
GEAR RATIOS
1ST 3.00:1
2ND 1.67:1
2ND Prime 1.50:1
3RD 1.0:1
4TH 0.75:1
5TH 0.67:1
REVERSE 3.00:1
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fitting, cooler line at trans 17.5 - 155
Bolt, torque convertor 31 23 -
Bolt/nut, crossmember 68 50 -
Bolt, driveplate to crankshaft 75 55 -
Bolt, oil pan 11.8 - 105
Screw, primary fluid filter 4.5 - 40
Bolt, oil pump 28.2 - 250
Bolt, oil pump body to cover 4.5 - 40
Screw, plate to oil pump body 4.5 - 40
Bolt, valve body to case 11.8 - 105
Plug, pressure test port 5.1 - 45
Bolt, reaction shaft support 11.8 - 105
Screw, valve body to transfer plate 5.6 - 50
Screw, solenoid module to transfer plate 5.7 - 50
Screw, accumulator cover 8 - 70
Screw, detent spring 4.5 - 40
Bolt, input speed sensor 11.8 - 105
Bolt, output speed sensor 11.8 - 105
Bolt, line pressure sensor 11.8 - 105
Bolt, extension housing 54 40 -
Valve, cooler return filter bypass 4.5 - 40
Screw, manual valve cam retaining 4.5 - 40
Bolt, manual lever 28.2 - 250
21 - 358 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

(28) Install the number 2 bearing onto the under-
drive hub with outer race against the hub with petro-
leum jelly.
(29) Install the underdrive hub into the input
clutch retainer.
(30) Install the number 3 bearing into the over-
drive hub with the outer race against the hub with
petroleum jelly.
(31) Install the overdrive hub into the input clutch
retainer.
(32) Install the number 4 bearing into the reverse
hub with outer race against the hub with petroleum
jelly.
(33) Install the reverse hub into the input clutch
retainer.
(34) Install the complete reverse clutch pack.
(35) Install the reverse reaction plate and snap-
ring.
(36) Push up on reaction plate to allow reverse
clutch to move freely.
INPUT SPEED SENSOR
DESCRIPTION
The Input and Output Speed Sensors are two-wire
magnetic pickup devices that generate AC signals as
rotation occurs. They are mounted in the left side of
the transmission case and are considered primary
inputs to the Transmission Control Module (TCM).
OPERATION
The Input Speed Sensor provides information on
how fast the input shaft is rotating. As the teeth of
the input clutch hub pass by the sensor coil, an AC
voltage is generated and sent to the TCM. The TCM
interprets this information as input shaft rpm.
The Output Speed Sensor generates an AC signal
in a similar fashion, though its coil is excited by rota-
tion of the rear planetary carrier lugs. The TCM
interprets this information as output shaft rpm.
The TCM compares the input and output speed
signals to determine the following:
²Transmission gear ratio
²Speed ratio error detection
²CVI calculation
The TCM also compares the input speed signal and
the engine speed signal to determine the following:
²Torque converter clutch slippage
²Torque converter element speed ratio
REMOVAL
(1) Raise vehicle.
(2) Place a suitable fluid catch pan under the
transmission.(3) Remove the wiring connector from the input
speed sensor (Fig. 91).
(4) Remove the bolt holding the input speed sensor
to the transmission case.
(5) Remove the input speed sensor from the trans-
mission case.
INSTALLATION
(1) Install the input speed sensor into the trans-
mission case.
(2) Install the bolt to hold the input speed sensor
into the transmission case. Tighten the bolt to 11.9
N´m (105 in.lbs.).
(3) Install the wiring connector onto the input
speed sensor
(4) Verify the transmission fluid level. Add fluid as
necessary.
(5) Lower vehicle.
LINE PRESSURE (LP) SENSOR
DESCRIPTION
The TCM utilizes a closed-loop system to control
transmission line pressure. The system contains a
variable force style solenoid, the Pressure Control
Solenoid, mounted on the side of the solenoid and
pressure switch assembly. The solenoid is duty cycle
controlled by the TCM to vent the unnecessary line
pressure supplied by the oil pump back to the sump.
The system also contains a variable pressure style
sensor, the Line Pressure Sensor, which is a direct
input to the TCM. The line pressure solenoid moni-
tors the transmission line pressure and completes the
Fig. 91 Input Speed Sensor
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
21 - 382 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
INPUT CLUTCH ASSEMBLY (Continued)