1998 DODGE RAM 1500 Reverse

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 - 373

OVERDRIVE CLUTCH
The overdrive clutch is hydraulically applied in
third (direct), fourth, and fifth gears by pressurized
fluid against the overdrive/reverse piston. When the
overdrive clutch is applied, the overdrive hub drives
the reverse carrier/input annulus assembly.
REVERSE CLUTCH
The reverse clutch is hydraulically applied in
reverse gear by pressurized fluid against the over-
drive/reverse piston. When the reverse clutch is
applied, the reaction annulus gear is driven.
DISASSEMBLY
(1) Remove the reverse reaction plate selective
snap-ring from the input clutch retainer (Fig. 79).
(2) Remove the reverse reaction plate from the
input clutch retainer.
(3) Remove the reverse hub and reverse clutch
pack from the input clutch retainer.
(4) Remove the number 4 bearing from the over-
drive hub.
(5) Remove the overdrive hub from the input
clutch retainer (Fig. 79).
Fig. 78 Input Clutch Assembly - Part 2
1 - BEARING NUMBER 3 10 - SNAP-RING (SELECT)
2 - OD HUB/SHAFT 11 - PLATE
3 - SNAP-RING (WAVE) 12 - DISC
4 - REV/OD REACTION PLATE 13 - OD CLUTCH
5 - BEARING NUMBER 4 14 - SNAP-RING (TAPERED)
6 - SNAP-RING (FLAT) 15 - UD/OD REACTION PLATE
7 - REVERSE HUB/SHAFT 16 - SNAP-RING (FLAT)
8 - REVERSE CLUTCH 17 - UD HUB/SHAFT
9 - REVERSE REACTION PLATE 18 - BEARING NUMBER 2
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INPUT CLUTCH ASSEMBLY (Continued)

(6) Remove the number 3 bearing from the under-
drive hub.
(7) Remove the OD/reverse reaction plate snap-
ring from the input clutch retainer.
(8) Remove the underdrive hub, overdrive clutch,
and overdrive reaction plate from the input clutch
retainer (Fig. 79).
NOTE: The overdrive friction discs and steel discs
are thicker than the matching components in the
underdrive and reverse clutches.(9) Remove the number 2 bearing from the input
clutch hub.
(10) Remove the overdrive clutch wave snap-ring
from the input clutch retainer.
(11) Remove the UD/OD reaction plate tapered
snap-ring from the input clutch retainer.
(12) Remove the UD/OD reaction plate from the
input clutch retainer.
(13) Remove the UD/OD reaction plate flat snap-
ring from the input clutch retainer (Fig. 79).
(14) Remove the underdrive clutch pack from the
input clutch retainer (Fig. 81).
Fig. 79 Input Clutch Assembly - Part 2
1 - BEARING NUMBER 3 10 - SNAP-RING (SELECT)
2 - OD HUB/SHAFT 11 - PLATE
3 - SNAP-RING (WAVE) 12 - DISC
4 - REV/OD REACTION PLATE 13 - OD CLUTCH
5 - BEARING NUMBER 4 14 - SNAP-RING (TAPERED)
6 - SNAP-RING (FLAT) 15 - UD/OD REACTION PLATE
7 - REVERSE HUB/SHAFT 16 - SNAP-RING (FLAT)
8 - REVERSE CLUTCH 17 - UD HUB/SHAFT
9 - REVERSE REACTION PLATE 18 - BEARING NUMBER 2
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 375
INPUT CLUTCH ASSEMBLY (Continued)

(15) Using Spring Compressor 8251, compress the
UD/OD balance piston and remove the snap-ring
from the input clutch hub (Fig. 80).(16) Remove the UD/OD balance piston and piston
return spring from the input clutch retainer (Fig. 81).
(17) Remove the underdrive piston from the input
clutch retainer (Fig. 81).
NOTE: Both the UD/OD balance piston and the
underdrive piston have seals molded onto them. If
the seal is damaged, do not attempt to install a new
seal onto the piston. The piston/seal must be
replaced as an assembly.
(18) Remove the input clutch retainer tapered
snap-ring.
(19) Separate input clutch retainer from input
clutch hub.
(20) Separate OD/reverse piston from input clutch
hub retainer (Fig. 81).
(21) Remove all seals and o-rings from the input
shaft and input hub. The o-rings on the input hub
are color coded. Be sure to make note of which o-ring
belongs in which location.
Fig. 80 Compressing UD/OD Balance Piston Using
Tool 8251
1 - PRESS
2 - TOOL 8251
3 - BALANCE PISTON
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INPUT CLUTCH ASSEMBLY (Continued)

ASSEMBLY
(1) Install all new seals and o-rings onto the input
shaft and input hub. The o-rings on the input hub
are color coded. Be sure to install the correct o-ring
in the correct location.
(2) Check the transmission lubrication check valve
located in the input shaft using shop air. The valve
should only allow air flow in one direction. If the
valve allows no air flow, or air flow in both direc-
tions, the valve will need to be replaced.(3) Lubricate all seals with MopartATF +4, Auto-
matic Transmission Fluid, prior to installation.
(4) Assemble the OD/reverse piston onto the input
clutch hub (Fig. 82).
(5) Assemble the input clutch retainer onto the
input clutch hub.
(6) Install the input clutch retainer tapered snap-
ring with tapered side up onto the input clutch hub.
Fig. 82 Input Clutch Assembly - Part I
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
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INPUT CLUTCH ASSEMBLY (Continued)

separator plates can be identified by the lack of the
half-moon cuts in the locating tabs.
(19) Install the overdrive clutch wavy snap-ring
with the two tabbed ears into the input clutch
retainer.
(20) Install the OD/reverse reaction plate into the
input clutch retainer. The reaction plate is non-direc-
tional (Fig. 86).
(21) Install the OD/reverse reaction plate flat
snap-ring into the input clutch retainer.
(22) Mount a dial indicator to the assembly and
zero the indicator against the OD/reverse reactionplate (Fig. 89). Apply 20 psi of air pressure to the
overdrive clutch and record the dial indicator read-
ing. Measure and record OD clutch pack measure-
ment in four (4) places, 90É apart. Take average of
four measurements and compare with OD clutch
pack clearance specification.Verify that the clutch
clearance is 1.103-1.856 mm (0.043-0.073 in.). The
reaction plate is not selective. If the clutch clearance
is not within specification, replace the reaction plate
along with all the friction and steel discs.
(23) Install the reverse clutch pack into the input
clutch retainer (Fig. 86).
Fig. 86 Input Clutch Assembly - Part II
1 - BEARING NUMBER 3 10 - SNAP-RING (SELECT)
2 - OD HUB/SHAFT 11 - PLATE
3 - SNAP-RING (WAVE) 12 - DISC
4 - REV/OD REACTION PLATE 13 - OD CLUTCH
5 - BEARING NUMBER 4 14 - SNAP-RING (TAPERED)
6 - SNAP-RING (FLAT) 15 - UD/OD REACTION PLATE
7 - REVERSE HUB/SHAFT 16 - SNAP-RING (FLAT)
8 - REVERSE CLUTCH 17 - UD HUB/SHAFT
9 - REVERSE REACTION PLATE 18 - BEARING NUMBER 2
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INPUT CLUTCH ASSEMBLY (Continued)

(24) Install the reverse reaction plate into the
input clutch retainer.
(25) Install the reverse reaction plate selective
snap-ring into the input clutch retainer.
(26) Mount a dial indicator to the assembly, push
down on the clutch discs, pull up on the reaction
plate to ensure the plate is properly seated and zero
the indicator against the reverse clutch discs (Fig.90). Apply 20 psi of air pressure to the reverse clutch
and record the dial indicator reading. Measure and
record Reverse clutch pack measurement in four (4)
places, 90É apart. Take average of four measurements
and compare with Reverse clutch pack clearance
specification. The correct clutch clearance is 0.58-1.47
mm (0.023-0.058 in.). Adjust as necessary. Install the
chosen snap-ring and re-measure to verify selection.
(27) Remove the reverse clutch pack from the
input clutch retainer.
Fig. 87 Input Clutch Assembly Mounted on Tool
8260
1 - INPUT CLUTCH ASSEMBLY
2 - TOOL 8260
Fig. 88 Measuring UD Clutch Clearance
1 - TOOL C-3339
2 - UNDERDRIVE CLUTCH PACK
Fig. 89 Measuring OD Clutch Clearance
1 - TOOL C-3339
2 - OD/REV REACTION PLATE
Fig. 90 Measuring Reverse Clutch Clearance
1 - TOOL C-3339
2 - REVERSE CLUTCH PACK
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 381
INPUT CLUTCH ASSEMBLY (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
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INPUT CLUTCH ASSEMBLY (Continued)