1998 DODGE RAM 1500 ECU

(6) Check converter seating with a scale and
straightedge (Fig. 235). Surface of converter lugs
should be 19mm (0.75 in.) to the rear of the straight-
edge when converter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle.
(9) Fill the transmission with the recommended
fluid.
TORQUE CONVERTER
DRAINBACK VALVE
DESCRIPTION
The drainback valve is located in the transmission
cooler outlet (pressure) line.
OPERATION
The valve prevents fluid from draining from the
converter into the cooler and lines when the vehicle
is shut down for lengthy periods. Production valves
have a hose nipple at one end, while the opposite end
is threaded for a flare fitting. All valves have an
arrow (or similar mark) to indicate direction of flow
through the valve.
STANDARD PROCEDURE - TORQUE
CONVERTER DRAINBACK VALVE
The converter drainback check valve is located in
the cooler outlet (pressure) line near the radiator
tank. The valve prevents fluid drainback when the
vehicle is parked for lengthy periods. The valve check
ball is spring loaded and has an opening pressure of
approximately 2 psi.
The valve is serviced as an assembly; it is not
repairable. Do not clean the valve if restricted, or
contaminated by sludge, or debris. If the valve fails,
or if a transmission malfunction occurs that gener-
ates significant amounts of sludge and/or clutch par-
ticles and metal shavings, the valve must be
replaced.
If the valve is restricted, installed backwards, or in
the wrong line, it will cause an overheating condition
and possible transmission failure.
CAUTION: The drainback valve is a one-way flow
device. It must be properly oriented in terms of flow
direction for the cooler to function properly. The
valve must be installed in the pressure line. Other-
wise flow will be blocked and would cause an over-
heating condition and eventual transmission failure.
TOW/HAUL OVERDRIVE
SWITCH
DESCRIPTION
The tow/haul overdrive OFF (control) switch is
located in the shift lever arm (Fig. 236). The switch
is a momentary contact device that signals the PCM
to toggle current status of the overdrive function.
Fig. 235 Typical Method Of Checking Converter
Seating
1 - SCALE
2 - STRAIGHTEDGE
Fig. 236 Tow/Haul Overdrive Off Switch
DRAUTOMATIC TRANSMISSION - 48RE 21 - 261
TORQUE CONVERTER (Continued)

(11) Work manual lever shaft and electrical con-
nector out of transmission case.
(12) Lower valve body, rotate valve body away
from case, pull park rod out of sprag, and remove
valve body (Fig. 274).
DISASSEMBLY
CAUTION: Do not clamp any valve body component
in a vise. This practice can damage the component
resulting in unsatisfactory operation after assembly
and installation. Do not use pliers to remove any of
the valves, plugs or springs and do not force any of
the components out or into place. The valves and
valve body housings will be damaged if force is
used. Tag or mark the valve body springs for refer-
ence as they are removed. Do not allow them to
become intermixed.
(1) Disconnect wires from governor pressure sen-
sor and solenoid.
(2) Remove screws attaching governor body and
retainer plate to transfer plate.
(3) Remove retainer plate, governor body and gas-
ket from transfer plate.(4) Remove governor pressure sensor from gover-
nor body.
(5) Remove governor pressure solenoid by pulling
it straight out of bore in governor body. Remove and
discard solenoid O-rings if worn, cut, or torn.
(6) Remove small shoulder bolt that secures sole-
noid harness case connector to 3-4 accumulator hous-
ing (Fig. 275). Retain shoulder bolt. Either tape it to
harness or thread it back into accumulator housing
after connector removal.
(7) Unhook overdrive/converter solenoid harness
from 3-4 accumulator cover plate (Fig. 276).
Fig. 275 Solenoid Harness Case Connector
Shoulder Bolt
1 - SOLENOID HARNESS CASE CONNECTOR
2 - 3-4 ACCUMULATOR HOUSING
Fig. 276 Solenoid Harness Routing
1 - OVERDRIVE/CONVERTER SOLENOID WIRE HARNESS
2 - 3-4 ACCUMULATOR COVER PLATE
Fig. 274 Valve Body
1 - VALVE BODY
2 - WIRE HARNESS
3 - PARK ROD
4 - GOVERNOR PRESSURE SOLENOID
5 - GOVERNOR PRESSURE SENSOR
DRAUTOMATIC TRANSMISSION - 48RE 21 - 287
VALVE BODY (Continued)

(12) Secure detent ball and spring with Retainer
Tool 6583 (Fig. 281).
(13) Remove park rod E-clip and separate rod from
manual lever (Fig. 282).
(14) Remove E-clip and washer that retains throt-
tle lever shaft in manual lever (Fig. 283).
(15) Remove manual lever and throttle lever (Fig.
284). Rotate and lift manual lever off valve body and
throttle lever shaft. Then slide throttle lever out of
valve body.
(16) Position pencil magnet next to detent housing
to catch detent ball and spring. Then carefully
remove Retainer Tool 6583 and remove detent ball
and spring (Fig. 285).
Fig. 281 Detent Ball Spring
1 - SPECIAL TOOL 6583 POSITIONED ON DETENT HOUSING
Fig. 282 Park Rod
1 - MANUAL LEVER
2 - E-CLIP
3 - PARK ROD
Fig. 283 Throttle Lever E-Clip And Washer
1 - THROTTLE LEVER SHAFT
2 - E-CLIP AND WASHER
3 - MANUAL SHAFT
Fig. 284 Manual And Throttle Lever
1 - PARK ROD
2 - MANUAL LEVER ASSEMBLY
3 - THROTTLE LEVER
Fig. 285 Detent Ball And Spring
1 - DETENT HOUSING
2 - DETENT SPRING
3 - DETENT BALL
4 - PENCIL MAGNET
DRAUTOMATIC TRANSMISSION - 48RE 21 - 289
VALVE BODY (Continued)

VALVE BODY UPPER HOUSING
(1) Note location of check balls in valve body upper
housing (Fig. 299). Then remove the one large diam-
eter and the five smaller diameter check balls.
(2) Remove governor plug and shuttle valve covers
(Fig. 301).
(3) Remove E-clip that secures shuttle valve sec-
ondary spring on valve stem (Fig. 300).
(4) Remove throttle plug, primary spring, shuttle
valve, secondary spring, and spring guides (Fig. 301).
(5) Remove boost valve retainer, spring and valve
if not previously removed.
(6) Remove throttle plug and 1-2 and 2-3 governor
plugs (Fig. 288).
(7) Turn upper housing around and remove limit
valve and shift valve covers (Fig. 302).
(8) Remove limit valve housing. Then remove
retainer, spring, limit valve, and 2-3 throttle plug
from limit valve housing (Fig. 302).
(9) Remove 1-2 shift control valve and spring (Fig.
302).
(10) Remove 1-2 shift valve and spring (Fig. 302).
(11) Remove 2-3 shift valve and spring from valve
body (Fig. 302).
(12) Remove pressure plug cover (Fig. 302).
(13) Remove line pressure sleeve, throttle pressure
plug and spring (Fig. 302).
Fig. 299 Check Ball Locations In Upper Housing
1 - SMALL DIAMETER CHECK BALLS (5)
2 - LARGE DIAMETER CHECK BALL (1)
Fig. 300 Shuttle Valve E-Clip And Secondary Spring
1 - E-CLIP
2 - SECONDARY SPRING AND GUIDES
3 - SHUTTLE VALVE
21 - 294 AUTOMATIC TRANSMISSION - 48REDR
VALVE BODY (Continued)

BOOST VALVE TUBE AND BRACE
(1) Position valve body assembly so lower housing
is facing upward (Fig. 318).
(2) Lubricate tube ends and housing ports with
transmission fluid or petroleum jelly.
(3) Start tube in lower housing port first. Then
swing tube downward and work opposite end of tube
into upper housing port (Fig. 318).
(4) Insert and seat each end of tube in housings.
(5) Slide tube brace under tube and into alignment
with valve body screw holes (Fig. 319).
(6) Install and finger tighten three screws that
secure tube brace to valve body housings (Fig. 319).
(7) Bend tube brace tabs up and against tube to
hold it in position (Fig. 320).
(8) Tighten all valve body housing screws to 4 N´m
(35 in. lbs.) torque after tube and brace are installed.
Tighten screws in diagonal pattern starting at center
and working outward.
Fig. 318 Boost Valve Tube
1 - BOOST VALVE TUBE
2 - LOWER HOUSING
3 - DISENGAGE THIS END OF TUBE FIRST
4 - UPPER HOUSING
Fig. 319 Boost Valve Tube And Brace
1 - BOOST VALVE TUBE
2 - TUBE BRACE
Fig. 320 Securing Boost Valve Tube With Brace
Tabs
1 - BEND TABS UP AGAINST TUBE AS SHOWN
21 - 306 AUTOMATIC TRANSMISSION - 48REDR
VALVE BODY (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)

(12) Remove the bolts holding the transmission oil
pan to the transmission case.
(13) Remove the transmission oil pan from the
transmission case.
(14) Remove the primary oil filter and the oil
cooler return filter (Fig. 19).
(15) Remove the cooler return filter bypass valve.
(16) Remove the bolts holding the valve body to
the transmission case (Fig. 20).
(17) Remove the valve body from the transmission
case.(18) Remove the outer snap-ring securing the
transmission front cover into the transmission case
(Fig. 21).
(19) Remove the inner snap-ring securing the
transmission front cover to the oil pump (Fig. 21).
Fig. 19 Remove Primary Oil and Cooler Filters
1 - PRIMARY OIL FILTER
2 - COOLER RETURN FILTER
3 - COOLER RETURN FILTER BYPASS VALVE
4 - VALVE BODY
Fig. 20 Remove Valve Body Assembly
1 - VALVE BODY TO CASE BOLT (6)
Fig. 21 Remove Transmission Front Cover
1 - INNER SNAP-RING
2 - TRANSMISSION COVER
3 - OUTER SNAP-RING
21 - 322 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)