Index DODGE RAM 1500 1998 2.G Owner's Manual
Page 1965 of 2627
OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the tow/haul overdrive OFF
mode to be entered and the Tow/Haul lamp to be illu-
minated. Pressing the switch a second time causes
normal overdrive operation to be restored and the
tow/haul lamp to be turned off. The tow/haul over-
drive OFF mode defaults to ON after the ignition
switch is cycled OFF and ON. The normal position
for the control switch is the ON position. The switch
must be in this position to energize the solenoid and
allow a 3-4 upshift. The control switch indicator light
illuminates only when the tow/haul overdrive switch
is turned to the OFF position, or when illuminated
by the transmission control module.
DIAGNOSIS AND TESTING - OVERDRIVE
ELECTRICAL CONTROLS
The tow/haul overdrive off switch, valve body sole-
noid, case connectors and related wiring can all be
tested with a 12 volt test lamp or a volt/ohmmeter.
Check continuity of each component when diagnosis
indicates this is necessary.
Switch and solenoid continuity should be checked
whenever the transmission fails to shift into fourth
gear range.
REMOVAL
(1) Using a plastic trim tool, remove the tow/haul
overdrive off switch retainer from the shift lever (Fig.
237).(2) Pull the switch outwards to release it from the
connector in the lever (Fig. 238)
INSTALLATION
NOTE: There is enough slack in the wire to pull out
the connector from the lever.
(1) Pull the connector out of the lever just enough
to grasp it.
CAUTION: Be careful not to bend the pins on the
tow/haul overdrive off switch. Use care when
installing the switch, as it is not indexed, and can
be accidentally installed incorrectly.
(2) Install the tow/haul overdrive off switch into
the connector (Fig. 239)
(3) Push the tow/haul overdrive off switch and wir-
ing into the shift lever.
(4) Install the tow/haul overdrive off switch
retainer onto the shift lever.
Fig. 237 Tow/Haul Overdrive Off Switch Retainer
Fig. 238 Remove the Tow/Haul Overdrive Off Switch
Fig. 239 Install the Tow/Haul Overdrive Off Switch
21 - 262 AUTOMATIC TRANSMISSION - 48REDR
TOW/HAUL OVERDRIVE SWITCH (Continued)
Page 2089 of 2627
(13) Measure the low/reverse clutch pack clearance
and adjust as necessary. The correct clutch clearance
is 1.00-1.74 mm (0.039-0.075 in.).
(14) Install the overrunning clutch into the low/re-
verse clutch retainer making sure that the index
splines are aligned with the retainer.
(15) Install the overrunning clutch inner snap-
ring.
OIL PUMP
DESCRIPTION
The oil pump (Fig. 96) is located at the front of the
transmission inside the bell housing and behind the
transmission front cover. The oil pump consists of
two independent pumps (Fig. 97), a number of valves
(Fig. 98), a front seal (Fig. 99), and a bolt on reaction
shaft. The converter clutch switch and regulator
valves, pressure regulator valve, and converter pres-
sure limit valve are all located in the oil pump valve
body.
OPERATION
As the torque converter rotates, the converter hub
rotates the oil pump drive gear. As the drive gear
rotates both driven gears, a vacuum is created when
the gear teeth come out of mesh. This suction draws
fluid through the pump inlet from the oil pan. As the
gear teeth come back into mesh, pressurized fluid is
forced into the pump outlet and to the oil pump
valves.
At low speeds, both sides of the pump supply fluid
to the transmission. As the speed of the torque con-verter increases, the flow from both sides increases
until the flow from the primary side alone is suffi-
cient to meet system demands. At this point, the
check valve located between the two pumps closes.
The secondary side is shut down and the primary
side supplies all the fluid to the transmission.
CONVERTER CLUTCH SWITCH VALVE
The converter clutch switch valve is used to control
the hydraulic pressure supplied to the front (OFF)
side of the torque converter clutch.
Fig. 96 Oil Pump
1 - OIL PUMP TO CASE BOLT (6)
2 - OIL PUMP
Fig. 97 Oil Pump Gears
1 - PUMP HOUSING
2 - DRIVE GEAR
3 - DRIVEN GEARS
Fig. 98 Oil Pump Valves
1 - TORQUE CONVERTER CLUTCH ACCUMULATOR VALVE
2 - TORQUE CONVERTER CLUTCH CONTROL VALVE
3 - TORQUE CONVERTER CLUTCH SWITCH VALVE
4 - PUMP VALVE BODY
5 - PRESSURE REGULATOR VALVE
6 - TORQUE CONVERTER CLUTCH LIMIT VALVE
21 - 386 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
LOW/REVERSE CLUTCH (Continued)
Page 2096 of 2627
(2) Pull the switch outwards to release it from the
connector in the lever (Fig. 108)
INSTALLATION
NOTE: There is enough slack in the wire to pull out
the connector from the lever.
(1) Pull the connector out of the lever just enough
to grasp it.
CAUTION: Be careful not to bend the pins on the
tow/haul overdrive off switch. Use care when
installing the switch, as it is not indexed, and can
be accidentally installed incorrectly.
(2) Install the tow/haul overdrive off switch into
the connector (Fig. 109)
(3) Push the tow/haul overdrive off switch and wir-
ing into the shift lever.
(4) Install the tow/haul overdrive off switch
retainer onto the shift lever.
PISTONS
DESCRIPTION
There are several sizes and types of pistons used in
an automatic transmission. Some pistons are used to
apply clutches, while others are used to apply bands.
They all have in common the fact that they are
round or circular in shape, located within a smooth
walled cylinder, which is closed at one end and con-
verts fluid pressure into mechanical movement. The
fluid pressure exerted on the piston is contained
within the system through the use of piston rings or
seals.
OPERATION
The principal which makes this operation possible
is known as Pascal's Law. Pascal's Law can be stated
as: ªPressure on a confined fluid is transmitted
equally in all directions and acts with equal force on
equal areas.º
PRESSURE
Pressure (Fig. 110) is nothing more than force (lbs.)
divided by area (in or ft.), or force per unit area.
Given a 100 lb. block and an area of 100 sq. in. on
the floor, the pressure exerted by the block is: 100
lbs. 100 in or 1 pound per square inch, or PSI as it is
commonly referred to.
Fig. 108 Remove the Tow/Haul Overdrive Off Switch
Fig. 109 Install the Tow/Haul Overdrive Off SwitchFig. 110 Force and Pressure Relationship
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 393
TOW/HAUL OVERDRIVE SWITCH (Continued)
Page 2384 of 2627
and 25 mm (1 in.) on the bottom of windshield. Allow
at least three minutes drying time.
(6) Locatenewsupport spacers on support brack-
ets and adjust to lowest height. (Fig. 5)
(7) Position seven new foam spacers on the inside
surface of the windshield, flush with the lower and
side edges. (Fig. 7)
(8) Position three new foam spacers on the inside
surface of the windshield, at a minimum distance of
3 mm (0.12 in.) from the top edge of the windshield.
(Fig. 7)
(9) Apply a 13 mm (1/2 in.) high and 10 mm (3/8
in.) wide bead of urethane around the perimeter of
windshield. At the top, apply the bead 7 mm (1/4 in.)
inboard from the glass edge. On the other three sides
apply the bead 14 mm (0.55 in.) inboard from the
glass edge. The urethane bead should be shaped in a
triangular cross-section, this can be achieved by
notching the tip of the applicator (Fig. 8).
(10) Install the a-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - INSTALLATION)
(11) With the aid of a helper, position the wind-
shield over the windshield opening. Align the refer-
ence marks at the bottom of the windshield to the
support spacers.
(12) Slowly lower windshield glass to the fence
opening guiding the lower corners into proper posi-
tion. Beginning at the bottom and continuing to the
top, push glass onto fence along the A-Pillars. Push
windshield inward to the fence at the bottom corners
(Fig. 9).
(13) Push windshield upward, setting the wind-
shield to roof gap to 1.5 mm (0.06 in.) to 3 mm (0.12
in.) and ratchet up the adjustable support brackets.
(14) Using clean water, lightly mist the support
spacers.
(15) Clean excess urethane from exterior with
MOPARtSuper Clean or equivalent.
(16) Install cowl grill. (Refer to 23 - BODY/EXTE-
RIOR/COWL GRILLE - INSTALLATION).
(17) Install rear view mirror support bracket.
(Refer to 23 - BODY/INTERIOR/REAR VIEW MIR-
ROR - INSTALLATION).
(18) Install rear view mirror. (Refer to 23 - BODY/
INTERIOR/REAR VIEW MIRROR - INSTALLA-
TION).
(19) Install the a-pillar weatherstrip retainer.
(Refer to 23 - BODY/WEATHERSTRIP/SEALS/A-
PILLAR WEATHERSTRIP RETAINER - INSTALLA-
TION)
(20) After urethane has cured, remove tape strips
and water test windshield to verify repair.
Fig. 5 CENTER WINDSHIELD AND MARK AT
SUPPORT
1 - WINDSHIELD
2 - INDEX MARKS
3 - SUPPORT SPACERS
Fig. 6 WORK SURFACE SET UP
1 - WINDSHIELD AND MOLDINGS
2 - URETHANE BEAD AROUND GLASS 7mm (0.3 in.) FROM
EDGE
3 - BLOCKS
DRSTATIONARY GLASS 23 - 89
WINDSHIELD (Continued)
Page 2390 of 2627
BODY STRUCTURE
TABLE OF CONTENTS
page page
GAP AND FLUSH
SPECIFICATIONS.......................95
OPENING DIMENSIONS
SPECIFICATIONS - BODY OPENING
DIMENSIONS.........................99
SEALER LOCATIONS
SPECIFICATIONS......................102STRUCTURAL ADHESIVE LOCATIONS
SPECIFICATIONS......................112
WELD LOCATIONS
SPECIFICATIONS......................120
GAP AND FLUSH
SPECIFICATIONS
GAP & FLUSH DIMENSIONS INDEX
DESCRIPTION FIGURE
STANDARD CAB 1
QUAD CAB 2
PICKUP BOX 3
DRBODY STRUCTURE 23 - 95
Page 2394 of 2627
OPENING DIMENSIONS
SPECIFICATIONS - BODY OPENING
DIMENSIONS
INDEX
DESCRIPTION FIGURE
WINDSHIELD OPENING 4
DOOR OPENING - STANDARD
CAB5
DOOR OPENINGS - QUAD CAB 6
REAR WINDOW OPENING 7
ENGINE COMPARTMENT/FRONT
STRUCTURE8
Fig. 4 WINDSHIELD OPENING
DRBODY STRUCTURE 23 - 99
Page 2397 of 2627
SEALER LOCATIONS
SPECIFICATIONS
INDEX
DESCRIPTION FIGURE
LOWER WINDSHIELD PILLAR, LOWER PLENUM AND COWL BAR 9
DASH PANEL, LOWER PLENUM AND COWL SIDE PANEL 10
LOWER DASH PANEL, LOWER COWL SIDE AND FLOOR PAN SUPPORT 11
ROOF PANEL, OUTER BODY SIDE APERTURE AND BACKLITE 12
CAB BACK, BODY SIDE APERTURE - REAR AND BACKLITE LOWER CORNER 13
LOWER DASH PANEL AND FLOOR PAN 14
FLOOR PAN AND BODY SIDE APERTURE 15
FRONT FLOOR PAN AND REAR PAN 16
FLOOR PAN TO CAB BACK 17
PICKUP BOX 18
Fig. 9 LOWER WINDSHIELD PILLAR
23 - 102 BODY STRUCTUREDR
Page 2407 of 2627
STRUCTURAL ADHESIVE
LOCATIONS
SPECIFICATIONS
INDEX
DESCRIPTION FIGURE
FLOOR PAN AND SEAT MOUNTING FRONT CROSSMEMBER 19
FRONT FENDER 20
FLOOR PAN 21
INNER WHEELHOUSE TO INNER BOX SIDE PANEL 22
INNER BOX SIDE PANEL TO OUTER BOX SIDE PANEL 23
INNER WHEELHOUSE, CROSSMEMBERS AND CROSSMEMBER END SUPPORT
BRACKET TO INNER BOX SIDE PANEL24
INNER BOX SIDE PANEL TO OUTER BOX SIDE PANEL 25
INNER DOOR PANEL TO OUTER DOOR PANEL - FRONT DOOR (QUAD CAB) 26
INNER DOOR PANEL TO OUTER DOOR PANEL - FRONT DOOR (STANDARD CAB) 27
INNER DOOR PANEL TO OUTER DOOR PANEL - REAR DOOR (QUAD CAB) 28
SILL RAIL - STD CAB 29
SILL RAIL - QUAD CAB 30
Fig. 19 FLOOR PAN
23 - 112 BODY STRUCTUREDR
Page 2415 of 2627
WELD LOCATIONS
SPECIFICATIONS
INDEX
DESCRIPTION FIGURE
FENDER BRACE, CLOSURE TUBE AND FRAME MOUNTING BRACKET TO FRONT
FENDER SUPPORT, FRONT FENDER AND RADIATOR TUBE31
STEERING COLUMN SUPPORT, CONNECTOR WIRING BRACKET AND WELD NUTS
TO LOWER PLENUM PANEL32
WIPER ATTACHING WELD NUTS AND VACUUM RESERVOIR ATTACHING STUDS TO
COWL PAR PANEL33
DASH PANEL TO FRONT FLOOR PAN 34
DASH PANEL TO LOWER PLENUM PANEL 35
LOWER PLENUM PANEL TO COWL BACK PANEL 36
FRONT FENDER AND RADIATOR TUBE DASH PANEL, INSTRUMENT PANEL
MOUNTING BRACKET, AND WELD NUTS TO COWL SIDE PANEL - LEFT SIDE37
DASH PANEL, LOWER PLENUM PANEL AND COWL PANEL BAR TO COWL SIDE
PANEL - LEFT SIDE38
FRONT FENDER AND RADIATOR TUBE DASH PANEL, INSTRUMENT PANEL
MOUNTING BRACKET AND WELD NUTS TO COWL SIDE PANEL - RIGHT SIDE39
DASH PANEL, LOWER PLENUM PANEL AND COWL PANEL BAR TO COWL SIDE
PANEL - RIGHT SIDE40
REINFORCEMENT AND HEADLAMP MOUNTING PANEL TO OUTER FENDER PANEL 41
SEAT MOUNTING FRONT BRACKETS TO SEAT MOUNTING FRONT CROSSMEMBER
TO FRONT FLOOR PAN42
AIR BAG MODULE BRACKET SHIFTER MOUNTING PLATE AND REAR FLOOR PANE
TO FRONT FLOOR PAN43
RIGHT TO LEFT REAR FLOOR CROSSMEMBER AND RIGHT TO LEFT SEAT
MOUNTING CROSSMEMBER44
REAR FLOOR CROSSMEMBER, SEAT MOUNTING CROSSMEMBER AND
UNDERBODY SUPPORT TO FLOOR SILL45
SEAT MOUNTING FRONT CROSSMEMBER TO FRONT FLOOR PAN TO UNDERBODY
SUPPORT46
FRONT SEAT MOUNTING CROSSMEMBERS TO FRONT SEAT MOUNTING BRACKET
TO FRONT FLOOR PAN47
REAR FLOOR CROSSMEMBERS TO REAR FLOOR PAN 48
FLOOR SILL TO FRONT SEAT MOUNTING CROSSMEMBER, FRONT AND REAR
FLOOR PAN49
AIR BAG MODULE BRACKET, SHIFTER MOUNTING PLATE AND FRONT SEAT
MOUNTING CROSSMEMBER TO FRONT FLOOR PAN50
REAR SEAT MIDDLE MOUNTING PLATE TO REAR FLOOR PAN TO FRONT FLOOR
PA N51
REAR FLOOR CROSSMEMBER, SEAT MOUNTING CROSSMEMBER AND
UNDERBODY SUPPORT TO FLOOR SILL52
LEFT REAR CROSSMEMBER TO RIGHT REAR CROSSMEMBER TO REAR FLOOR
PA N53
23 - 120 BODY STRUCTUREDR
Page 2504 of 2627
(4) Reconnect the battery negative cable.
BLEND DOOR ACTUATOR
DESCRIPTION
The blend door actuators are reversible, 12-volt
Direct Current (DC), servo motors. Models with the
single zone heater and air conditioner system have a
single blend door, which is controlled by a single
blend door actuator. Models with the optional dual
zone front heater and air conditioner system have
dual blend doors, which are controlled by two blend
door actuators. The single zone blend door actuator is
located on the driver side end of the HVAC housing,
close to the dash panel. In the dual zone system, the
same blend door actuator used for the single zone
system becomes the driver side blend door actuator,
and is mechanically connected to only the driver side
blend door. In the dual zone system, a second sepa-
rate blend door actuator is also located on the top of
the HVAC housing and is mechanically connected to
only the passenger side blend door.
The blend door actuators are interchangeable with
each other, as well as with the actuators for the
mode door, defrost door and the recirculation door.
Each actuator is contained within an identical blackmolded plastic housing with an integral wire connec-
tor receptacle. Integral mounting tabs allow the
actuator to be secured with three screws to the
HVAC housing. Each actuator also has an identical
output shaft with splines that connects it to the link-
age that drives the proper door. The blend door
actuators do not require mechanical indexing to the
blend door linkage, as they are electronically cali-
brated by the heater-A/C control module. The blend
door actuators cannot be adjusted or repaired and, if
damaged or faulty, they must be replaced.
OPERATION
Each blend door actuator is connected to the A/C-
heater control through the vehicle electrical system by a
dedicated two-wire lead and connector from the HVAC
wire harness. The blend door actuator can move the
blend-air door in two directions. When the A/C-heater
control pulls the voltage on one side of the motor con-
nection high and the other connection low, the blend-air
door will move in one direction. When the A/C-heater
control reverses the polarity of the voltage to the motor,
the blend-air door moves in the opposite direction.
When the A/C-heater control makes the voltage to both
connections high or both connections low, the blend-air
door stops and will not move. The motor connections
also provide a feedback signal to the A/C-heater control.
This feedback signal allows the A/C-heater control to
monitor the operation and relative positions of the blend
door actuator and the blend-air door. The A/C-heater
control learns the blend door stop positions during the
calibration procedure and will store a diagnostic trouble
code (DTC) for any problems it detects in the blend door
actuator circuits.
The blend door actuator can be diagnosed using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures for more information. The blend door actuators
cannot be adjusted or repaired and, if damaged or
faulty, they must be replaced.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
Fig. 15 A/C Pressure Transducer - 3.7L Shown
1 - NUT
2 - FRONT UPPER CROSSMEMBER
3 - A/C CONDENSER
4 - NUT (2)
5 - SUCTION LINE
6 - A/C COMPRESSOR
7 - A/C PRESSURE TRANSDUCER
8 - WIRE HARNESS CONNECTOR
9 - A/C DISCHARGE LINE
DRCONTROLS 24 - 17
A/C PRESSURE TRANSDUCER (Continued)