1998 DODGE RAM 1500 Schematic

AUTOMATIC TRANSMISSION - 48RE
TABLE OF CONTENTS
page page
AUTOMATIC TRANSMISSION - 48RE
DESCRIPTION........................132
OPERATION..........................134
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION.....................140
DIAGNOSIS AND TESTING - PRELIMINARY . 140
DIAGNOSIS AND TESTING - ROAD
TESTING...........................140
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TEST....................141
DIAGNOSIS AND TESTING - AIR TESTING
TRANSMISSION CLUTCH AND BAND
OPERATION........................144
DIAGNOSIS AND TESTING - CONVERTER
HOUSING FLUID LEAK................144
DIAGNOSIS AND TESTING - DIAGNOSIS
CHARTS...........................145
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR.....................158
REMOVAL............................158
DISASSEMBLY........................160
CLEANING...........................166
INSPECTION.........................166
ASSEMBLY...........................166
INSTALLATION........................174
SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS.............176
SPECIFICATIONS
TRANSMISSION.....................189
SPECIAL TOOLS
RE TRANSMISSION..................191
ACCUMULATOR
DESCRIPTION........................193
OPERATION..........................193
INSPECTION.........................194
BANDS
DESCRIPTION........................194
OPERATION..........................194
ADJUSTMENTS
ADJUSTMENT - BANDS...............195
BRAKE TRANSMISSION SHIFT INTERLOCK
SYSTEM
DESCRIPTION........................196
OPERATION..........................196
DIAGNOSIS AND TESTING - BRAKE
TRANSMISSION SHIFT INTERLOCK......196
ADJUSTMENTS - BRAKE TRANSMISSION
SHIFT INTERLOCK...................196ELECTRONIC GOVERNOR
DESCRIPTION........................197
OPERATION..........................198
REMOVAL............................199
INSTALLATION........................200
EXTENSION HOUSING SEAL
REMOVAL............................201
INSTALLATION........................201
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL.............201
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID.......................201
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION....................202
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK............................202
STANDARD PROCEDURE - FLUID AND
FILTER REPLACEMENT...............203
STANDARD PROCEDURE - TRANSMISSION
FILL...............................204
FRONT CLUTCH
DESCRIPTION........................205
OPERATION..........................205
DISASSEMBLY........................205
INSPECTION.........................206
ASSEMBLY...........................207
FRONT SERVO
DESCRIPTION........................208
OPERATION..........................208
DISASSEMBLY........................209
CLEANING...........................209
INSPECTION.........................209
ASSEMBLY...........................209
GEARSHIFT CABLE
DIAGNOSIS AND TESTING - GEARSHIFT
CABLE.............................210
REMOVAL............................210
INSTALLATION........................211
ADJUSTMENTS
GEARSHIFT CABLE..................212
OIL PUMP
DESCRIPTION........................213
OPERATION..........................213
DISASSEMBLY........................214
CLEANING...........................214
INSPECTION.........................214
ASSEMBLY...........................214
21 - 130 AUTOMATIC TRANSMISSION - 48REDR

TORQUE CONVERTER LEAK POINTS
Possible sources of converter leaks are:
²Leaks at the weld joint around the outside diam-
eter weld.
²Leaks at the converter hub weld.
CONVERTER HOUSING AREA LEAK CORRECTION
(1) Remove converter.
(2) Tighten front band adjusting screw until band
is tight around front clutch retainer. This prevents
front/rear clutches from coming out when oil pump is
removed.
(3) Remove oil pump and remove pump seal.
Inspect pump housing drainback and vent holes for
obstructions. Clear holes with solvent and wire.(4) Inspect pump bushing and converter hub. If
bushing is scored, replace it. If converter hub is
scored, either polish it with crocus cloth or replace
converter.
(5) Install new pump seal, O-ring, and gasket.
Replace oil pump if cracked, porous or damaged in
any way. Be sure to loosen the front band before
installing the oil pump, damage to the oil pump seal
may occur if the band is still tightened to the front
clutch retainer.
(6) Loosen kickdown lever pin access plug three
turns. Apply LoctiteŸ 592, or PermatextNo.2to
plug threads and tighten plug to 17 N´m (150 in. lbs.)
torque.
(7) Adjust front band.
(8) Lubricate pump seal and converter hub with
transmission fluid or petroleum jelly and install con-
verter.
(9) Install transmission and converter housing
dust shield.
(10) Lower vehicle.
DIAGNOSIS AND TESTING - DIAGNOSIS
CHARTS
The diagnosis charts provide additional reference
when diagnosing a transmission fault. The charts
provide general information on a variety of transmis-
sion, overdrive unit and converter clutch fault condi-
tions.
The hydraulic flow charts in the Schematics and
Diagrams section of this group, outline fluid flow and
hydraulic circuitry. Circuit operation is provided for
PARK, NEUTRAL, FIRST, SECOND, THIRD,
FOURTH, MANUAL FIRST, MANUAL SECOND,
and REVERSE gear ranges. Normal working pres-
sures are also supplied for each of the gear ranges.
Fig. 11 Converter Housing Leak Paths
1 - PUMP SEAL
2 - PUMP VENT
3 - PUMP BOLT
4 - PUMP GASKET
5 - CONVERTER HOUSING
6 - CONVERTER
7 - REAR MAIN SEAL LEAK
DRAUTOMATIC TRANSMISSION - 48RE 21 - 145
AUTOMATIC TRANSMISSION - 48RE (Continued)

SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS
HYDRAULIC FLOW IN PARK
21 - 176 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

OPERATION
NOTE: Refer to the Hydraulic Schematics for a
visual aid in determining valve location, operation
and design.
CHECK BALLS
CHECK BALL NUMBER DESCRIPTION
1 Allows either the manual valve to put line pressure on the 1-2 governor plug or
the KD Valve to put WOT line pressure on the 1-2 governor plug.
3 Allows either the Reverse circuit or the 3rd gear circuit to pressurize the front
clutch.
4 Allows either the Manual Low circuit from the Manual Valve or the Reverse
from the Manual Valve circuit to pressurize the rear servo.
5 Directs line pressure to the spring end of the 2-3 shift valve in either Manual
Low or Manual 2nd, forcing the downshift to 2nd gear regardless of governor
pressure.
6 Provides a by-pass around the front servo orifice so that the servo can release
quickly.
7 Provides a by-pass around the rear clutch orifice so that the clutch can release
quickly.
8 Directs reverse line pressure through an orifice to the throttle valve eliminating
the extra leakage and insuring that Reverse line pressure pressure will be
sufficient.
9 Provides a by-pass around the rear servo orifice so that the servo can release
quickly.
10 Allows the lockup clutch to used at WOT in 3rd gear by putting line pressure
from the 3-4 Timing Valve on the interlock area of the 2-3 shift valve, thereby
preventing a 3rd gear Lock-up to 2nd gear kickdown.
21 - 272 AUTOMATIC TRANSMISSION - 48REDR
VALVE BODY (Continued)

AUTOMATIC TRANSMISSION - 45RFE/545RFE
TABLE OF CONTENTS
page page
AUTOMATIC TRANSMISSION - 45RFE/545RFE
DESCRIPTION........................312
OPERATION..........................313
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION.....................314
DIAGNOSIS AND TESTING -
PRELIMINARY.......................314
DIAGNOSIS AND TESTING - ROAD
TESTING...........................314
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TEST....................316
DIAGNOSIS AND TESTING - AIR CHECKING
TRANSMISSION CLUTCH OPERATION....317
DIAGNOSIS AND TESTING - CONVERTER
HOUSING FLUID LEAK................318
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR.....................318
REMOVAL............................318
DISASSEMBLY........................320
CLEANING...........................326
INSPECTION.........................326
ASSEMBLY...........................326
INSTALLATION........................333
SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS.............337
SPECIFICATIONS
TRANSMISSION.....................358
SPECIAL TOOLS
RFE TRANSMISSION.................359
4C RETAINER/BULKHEAD
DISASSEMBLY........................362
ASSEMBLY...........................363
ADAPTER HOUSING SEAL
REMOVAL............................364
INSTALLATION........................364
BRAKE TRANSMISSION SHIFT INTERLOCK
SYSTEM
DESCRIPTION........................364
OPERATION..........................364
DIAGNOSIS AND TESTING - BRAKE
TRANSMISSION SHIFT INTERLOCK......364
ADJUSTMENTS - BRAKE TRANSMISSION
SHIFT INTERLOCK...................365
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL.............366
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID.......................366DIAGNOSIS AND TESTING - FLUID
CONTAMINATION....................366
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK............................366
STANDARD PROCEDURE - FLUID AND
FILTER REPLACEMENT...............367
STANDARD PROCEDURE - TRANSMISSION
FILL...............................368
GEARSHIFT CABLE
DIAGNOSIS AND TESTING - GEARSHIFT
CABLE.............................368
REMOVAL............................369
INSTALLATION........................370
ADJUSTMENTS
GEARSHIFT CABLE..................370
HOLDING CLUTCHES
DESCRIPTION........................371
OPERATION..........................372
INPUT CLUTCH ASSEMBLY
DESCRIPTION........................373
OPERATION..........................373
DISASSEMBLY........................374
ASSEMBLY...........................378
INPUT SPEED SENSOR
DESCRIPTION........................382
OPERATION..........................382
REMOVAL............................382
INSTALLATION........................382
LINE PRESSURE (LP) SENSOR
DESCRIPTION........................382
OPERATION..........................383
REMOVAL............................383
INSTALLATION........................383
LOW/REVERSE CLUTCH
DISASSEMBLY........................384
CLEANING...........................385
INSPECTION.........................385
ASSEMBLY...........................385
OIL PUMP
DESCRIPTION........................386
OPERATION..........................386
STANDARD PROCEDURE - OIL PUMP
VOLUME CHECK.....................387
DISASSEMBLY........................388
CLEANING...........................390
INSPECTION.........................390
ASSEMBLY...........................390
OIL PUMP FRONT SEAL
REMOVAL............................391
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 311

DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TEST
An accurate tachometer and pressure test gauges
are required. Test Gauge C-3293-SP has a 300 psi
range and is used at all locations where pressures
exceed 100 psi.
Pressure Test Port Locations
Only two pressure ports are supplied on the trans-
mission case. The torque converter clutch apply and
release ports are located on the right side of the
transmission case (Fig. 2).
To determine the line pressure, there are two avail-
able methods. The DRBtscan tool can be used to
read line pressure from the line pressure sensor. The
second method is to install Line Pressure Adapter
8259 (Fig. 4) into the transmission case and then
install the pressure gauge and the original sensor
into the adapter. This will allow a comparison of the
DRBtreadings and the gauge reading to determine
the accuracy of the line pressure sensor. The DRBt
line pressure reading should match the gauge read-
ing within  10 psi.
In order to access any other pressure tap locations,
the transmission oil pan must be removed, the pres-
sure port plugs removed and Valve Body Pressure
Tap Adapter 8258-A (Fig. 5) installed. The extensions
supplied with Adapter 8258-A will allow the installa-
tion of pressure gauges to the valve body. Refer to
(Fig. 3) for correct pressure tap location identifica-
tion.
TEST PROCEDURE
All pressure readings should be taken with the
transmission fluid level full, transmission oil at the
normal operating temperature, and the engine at
1500 rpm. Check the transmission for proper opera-
tion in each gear position that is in question or if a
specific element is in question, check the pressure
readings in at least two gear positions that employ
that element. Refer to the Hydraulic Schematics at
the rear of this section to determine the correct pres-
sures for each element in a given gear position.
Fig. 2 Torque Converter Pressure Locations
1 - TCC RELEASE
2 - TO COOLER
3 - TCC APPLY
4 - FROM COOLER
5 - LINE PRESSURE SENSOR
Fig. 3 Pressure Tap Locations
Fig. 4 Line Pressure Adapter 8259
1 - LINE PRESSURE SENSOR PORT
2 - LINE PRESSURE SENSOR
3 - TOOL 8259
4 - PRESSURE TAP
21 - 316 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS
HYDRAULIC FLOW IN PARK/NEUTRAL
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 337
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

INSTALLATION
(1) Place TRS selector plate in the PARK position.
(2) Position the transmission solenoid/TRS assem-
bly onto the valve body. Be sure that both alignment
dowels are fully seated in the valve body and that
the TRS switch contacts are properly positioned in
the selector plate
(3) Install the screws to hold the transmission
solenoid/TRS assembly onto the valve body.
(4) Tighten the solenoid assembly screws adjacent
to the arrows cast into the bottom of the valve body
first. Tighten the screws to 5.7 N´m (50 in.lbs.).
(5) Tighten the remainder of the solenoid assembly
screws to 5.7 N´m (50 in.lbs.).
(6) Install the valve body into the transmission.
TRANSMISSION
TEMPERATURE SENSOR
DESCRIPTION
The transmission temperature sensor is a ther-
mistor that is integral to the Transmission Range
Sensor (TRS).
OPERATION
The transmission temperature sensor is used by
the TCM to sense the temperature of the fluid in the
sump. Since fluid temperature can affect transmis-
sion shift quality and convertor lock up, the TCM
requires this information to determine which shift
schedule to operate in.
Calculated Temperature
A failure in the temperature sensor or circuit will
result in calculated temperature being substituted for
actual temperature. Calculated temperature is a pre-
dicted fluid temperature which is calculated from a
combination of inputs:
²Battery (ambient) temperature
²Engine coolant temperature
²In-gear run time since start-up
VALVE BODY
DESCRIPTION
The valve body consists of a cast aluminum valve
body, a separator plate, and a transfer plate. The
valve body contains valves and check balls that con-
trol fluid delivery to the torque converter clutch,
bands, and frictional clutches. The valve body con-
tains the following components (Fig. 129) and (Fig.
130):
²Solenoid switch valve
²Manual valve
²Low/reverse switch valve
²5 Accumulators
²7 check balls
OPERATION
NOTE: Refer to the Hydraulic Schematics for a
visual aid in determining valve location, operation
and design.
SOLENOID SWITCH VALVE
The Solenoid Switch Valve (SSV) controls the direc-
tion of the transmission fluid when the L/R-TCC sole-
noid is energized.
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.
MANUAL VALVE
The manual valve is a relay valve. The purpose of
the manual valve is to direct fluid to the correct cir-
cuit needed for a specific gear or driving range. The
manual valve, as the name implies, is manually oper-
ated by the driver with a lever located on the top of
the valve body. The valve is connected mechanically
by a cable to the gearshift mechanism. The valve is
held in each of its positions by a roller detent spring
(Fig. 131) that engages the ªroostercombº of the TRS
selector plate.
21 - 408 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
TRANSMISSION SOLENOID/TRS ASSEMBLY (Continued)