1998 DODGE RAM 1500 Page 22

FUEL INJECTION - DIESEL
TABLE OF CONTENTS
page page
ACCELERATOR PEDAL POSITION SENSOR
DESCRIPTION.........................68
OPERATION...........................68
REMOVAL.............................68
INSTALLATION.........................71
CAMSHAFT POSITION SENSOR
DESCRIPTION.........................71
OPERATION...........................71
REMOVAL.............................72
INSTALLATION.........................72
CRANKSHAFT POSITION SENSOR
DESCRIPTION.........................72
OPERATION...........................72
REMOVAL.............................73
INSTALLATION.........................73
FUEL CONTROL ACTUATOR
DESCRIPTION.........................74
OPERATION...........................74
REMOVAL.............................74
FUEL INJECTOR
DESCRIPTION.........................74
OPERATION...........................74
REMOVAL.............................75
INSTALLATION.........................77
FUEL INJECTOR RAIL
DESCRIPTION.........................78
OPERATION...........................78
REMOVAL.............................78
INSTALLATION.........................78INLET AIR TEMPERATURE SENSOR/
PRESSURE SENSOR
DESCRIPTION.........................79
OPERATION...........................79
REMOVAL.............................79
INSTALLATION.........................79
INTAKE AIR HEATER
DESCRIPTION.........................80
OPERATION...........................80
REMOVAL.............................80
INSTALLATION.........................80
INTAKE AIR HEATER RELAY
DESCRIPTION.........................82
OPERATION...........................82
REMOVAL.............................82
INSTALLATION.........................82
INTAKE AIR TEMPERATURE SENSOR/MAP
SENSOR
DESCRIPTION.........................82
OPERATION...........................82
REMOVAL.............................82
INSTALLATION.........................82
MAP SENSOR
DESCRIPTION.........................83
THROTTLE CONTROL CABLE
REMOVAL.............................83
INSTALLATION.........................84
PTO SWITCH
DESCRIPTION.........................85
OPERATION...........................85
ACCELERATOR PEDAL
POSITION SENSOR
DESCRIPTION
Engine Mounted Sensor:The APPS assembly is
located at the top-left-front of the engine. A plastic
cover is used to cover the assembly. The actual sen-
sor is located behind its mounting bracket.
Battery Tray Mounted Sensor:The Accelerator
Pedal Position Sensor (APPS) assembly is located
under the vehicle battery tray. A cable connects the
assembly to the accelerator pedal. A plastic cover
with a movable door is used to cover the assembly.
OPERATION
Engine Mounted Sensor:The Accelerator Pedal
Position Sensor (APPS) is a linear potentiometer. Itprovides the Engine Control Module (ECM) with a
DC voltage signal proportional to the angle, or posi-
tion of the accelerator pedal.
Battery Tray Mounted Sensor:The APPS pro-
vides the ECM with two DC voltage signals which
change as the position of the accelerator changes.
One of the DC voltage signals will be half the voltage
of the other signal.
REMOVAL
Engine Mounted Sensor :
The APPS is serviced (replaced) as one assembly
including the lever, brackets and sensor. The APPS is
calibrated to its mounting bracket. The APPS assem-
bly is located at left-front of engine below plastic
cable/lever/linkage cover (Fig. 1).
14 - 68 FUEL INJECTION - DIESELDR

STEERING
TABLE OF CONTENTS
page page
STEERING
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER
STEERING SYSTEM....................2
DIAGNOSIS AND TESTING - POWER
STEERING FLOW AND PRESSURE........4
SPECIAL TOOLS
STEERING...........................5COLUMN...............................6
GEAR - INDEPENDENT FRONT SUSPENSION..17
GEAR - LINK/COIL.......................20
LINKAGE - INDEPENDENT FRONT
SUSPENSION...........................32
LINKAGE - LINK/COIL....................34
PUMP.................................39
STEERING
DESCRIPTION
CAUTION: MOPARTATF+4 is to be used in the
power steering system. No other power steering or
automatic transmission fluid is to be used in the
system. Damage may result to the power steering
pump and system if any other fluid is used, and do
not overfill.
Power steering systems consist of:
²Steering column
²Rack and pinion steering gear
²Belt driven hydraulic steering pump
²Pump pressure and return hoses
²Oil Cooler
OPERATION
The steering column shaft is attached to the gear
pinion. The rotation of the pinion moves the gear
rack from side-to-side. This lateral action of the rack
pushes and pulls the tie rods to change the direction
of the front wheels (Fig. 1).
Power assist is provided by an engine mounted
hydraulic pump which supplies hydraulic fluid pres-
sure to the steering gear.
Fig. 1 STEERING COMPONENTS
1 - POWER STEERING PUMP ASSEMBLY
2 - RESERVOIR
3 - HOSES
4 - TIE ROD ENDS
5 - MOUNTING BOLTS
6 - RACK & PINION
DRSTEERING 19 - 1

COLUMN
TABLE OF CONTENTS
page page
COLUMN
DESCRIPTION..........................6
DIAGNOSIS AND TESTING - STEERING
COLUMN.............................7
REMOVAL.............................7
INSTALLATION..........................9
IGNITION SWITCH
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING - IGNITION
SWITCH.............................9
REMOVAL.............................10
INSTALLATION.........................11
KEY-IN IGNITION SWITCH
DESCRIPTION.........................11
DIAGNOSIS AND TESTING - IGNITION
SWITCH AND KEY LOCK CYLINDER.......11
KEY CYLINDER
REMOVAL.............................12
INSTALLATION.........................12GEAR SHIFT LEVER
REMOVAL.............................12
INSTALLATION.........................12
UPPER STEERING COUPLING
REMOVAL.............................13
INSTALLATION.........................13
LOWER STEERING COUPLING
REMOVAL
REMOVAL - ALL LD & HD EXCEPT 4X4 HD . 14
REMOVAL - 4X4 HD...................14
INSTALLATION
INSTALLATION - ALL LD & HD EXCEPT 4X4
HD.................................14
INSTALLATION - 4X4 HD................15
STEERING WHEEL
REMOVAL.............................15
INSTALLATION.........................15
TILT LEVER KNOB RELEASE
REMOVAL.............................16
INSTALLATION.........................16
COLUMN
DESCRIPTION
NOTE: The steering column on vehicles with an
automatic transmission may not be equipped with
an internal locking shaft that allows the ignition key
cylinder to be locked with the key. Alternative meth-
ods of locking the steering wheel for service will
have to be used.
The tilt and standard column (Fig. 1) has been
designed to be serviced as an assembly; less wiring,
switches, shrouds, steering wheel, etc. Most steering
column components can be serviced without remov-
ing the steering column from the vehicle.
To service the steering wheel, switches or airbag,
refer to Restraints and follow all WARNINGS and
CAUTIONS.
WARNING: THE AIRBAG SYSTEM IS A SENSITIVE,
COMPLEX ELECTRO-MECHANICAL UNIT. BEFORE
ATTEMPTING TO DIAGNOSE, REMOVE OR INSTALL
THE AIRBAG SYSTEM COMPONENTS YOU MUST
FIRST DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE. THEN WAIT TWO
MINUTES FOR THE SYSTEM CAPACITOR TO DIS-
CHARGE. FAILURE TO DO SO COULD RESULT INACCIDENTAL DEPLOYMENT OF THE AIRBAG AND
POSSIBLE PERSONAL INJURY. THE FASTENERS,
SCREWS, AND BOLTS, ORIGINALLY USED FOR
THE AIRBAG COMPONENTS, HAVE SPECIAL COAT-
INGS AND ARE SPECIFICALLY DESIGNED FOR THE
AIRBAG SYSTEM. THEY MUST NEVER BE
REPLACED WITH ANY SUBSTITUTES. ANYTIME A
NEW FASTENER IS NEEDED, REPLACE WITH THE
CORRECT FASTENERS PROVIDED IN THE SERVICE
PACKAGE OR FASTENERS LISTED IN THE PARTS
BOOKS.
CAUTION: Do not hammer on steering column
shaft. This may cause damage to the shaft or bear-
ing.
CAUTION: Do not attempt to remove the pivot bolts
to disassemble the tilting mechanism. Do not
remove shaft lock plate or plate retainer. This will
damage the column.
CAUTION: Do not attempt to remove or modify the
park lock slider or link.
19 - 6 COLUMNDR

GEAR - INDEPENDENT FRONT SUSPENSION
TABLE OF CONTENTS
page page
GEAR - INDEPENDENT FRONT SUSPENSION
DESCRIPTION.........................17
REMOVAL.............................17
INSTALLATION.........................18
SPECIFICATIONS
TORQUE CHART......................19BUSHING
REMOVAL.............................19
INSTALLATION.........................19
GEAR - INDEPENDENT FRONT
SUSPENSION
DESCRIPTION
A rack and pinion steering gears (Fig. 1) is made
up of two main components, the pinon shaft and the
rack. The gear cannot be adjusted or internally ser-
viced. If a malfunction or a fluid leak occurs, the gear
must be replaced as an assembly.
REMOVAL
NOTE: The steering column on vehicles with an
automatic transmission may not be equipped with
an internal locking shaft that allows the ignition key
cylinder to be locked with the key. Alternative meth-
ods of locking the steering wheel for service will
have to be used.
(1) Lock the steering wheel.(2) Drain and siphon the power steering fluid from
the reservoir.
(3) Raise the vehicle.
(4) Remove and discard the steering coupler pinch
bolt.
(5) Remove the power steering hoses from the rack
& pinion.
(6) Remove the tire and wheel assembly.
(7) Remove the tie rod end nuts and separate tie
rod ends from the knuckles with Special tool 8677
(Refer to 19 - STEERING/LINKAGE/TIE ROD END -
REMOVAL).
(8) Remove the skid plate (Refer to 13 - FRAME &
BUMPERS/FRAME/FRONT SKID PLATE -
REMOVAL).
(9) Remove the rack & pinion mounting bolts. (Fig.
2) & (Fig. 3)
(10) Remove the rack & pinion from the vehicle.
Fig. 1 STEERING GEAR
1 - OUTER TIE ROD ENDS
2 - MOUNTING BUSHINGS
3 - BELLOWS
Fig. 2 STEERING GEAR MOUNTING BOLTS
1 - STEERING GEAR MOUNTING BOLTS 4X4
DRGEAR - INDEPENDENT FRONT SUSPENSION 19 - 17

GEAR - LINK/COIL
TABLE OF CONTENTS
page page
GEAR - LINK/COIL
DESCRIPTION.........................20
OPERATION...........................20
REMOVAL.............................20
INSTALLATION.........................21
ADJUSTMENTS
ADJUSTMENT........................21
SPECIFICATIONS
POWER STEERING GEAR..............22
TORQUE CHART......................23
SPECIAL TOOLS
POWER STEERING GEAR..............23
PITMAN SHAFT SEAL
REMOVAL
REMOVAL - GAS ENGINE...............25REMOVAL - DIESEL...................25
INSTALLATION
INSTALLATION - GAS ENGINE...........26
INSTALLATION - DIESEL................26
STEERING GEAR INPUT SHAFT SEAL
REMOVAL.............................27
INSTALLATION.........................29
PITMAN SHAFT
REMOVAL
REMOVAL - GAS......................30
REMOVAL - DIESEL...................30
INSTALLATION
INSTALLATION - GAS..................31
INSTALLATION - DIESEL................31
GEAR - LINK/COIL
DESCRIPTION
The power steering gear is a recirculating ball type
gear (Fig. 1). The gear ratio's used are 12.5:1.
OPERATION
The gear acts as a rolling thread between the
worm shaft and rack piston. The worm shaft is sup-
ported by a thrust bearing at the lower end and a
bearing assembly at the upper end. When the worm
shaft is turned from input from the steering column
the rack piston moves. The rack piston teeth mesh
with the pitman shaft. Turning the worm shaft, turns
the pitman shaft, which turns the steering linkage.
REMOVAL
(1) Place the front wheels in a straight-ahead posi-
tion.
NOTE: The steering column on vehicles with an
automatic transmission may not be equipped with
an internal locking shaft that allows the ignition key
cylinder to be locked with the key. Alternative meth-
ods of locking the steering wheel for service will
have to be used.
(2) Lock the steering wheel.
(3) Siphon out as much power steering fluid as
possible.
Fig. 1 STEERING GEAR
1 - INPUT SHAFT
2 - OUTLET
3 - INLET
4 - VALVE ASSEMBLY HOUSING
5 - PITMAN SHAFT COVER BOLTS
6 - STEERING GEAR
7 - MESHLOAD ADJUSTER NUT
8 - PITMAN SHAFT
19 - 20 GEAR - LINK/COILDR

LINKAGE - INDEPENDENT FRONT SUSPENSION
TABLE OF CONTENTS
page page
LINKAGE - INDEPENDENT FRONT
SUSPENSION
DIAGNOSIS AND TESTING - OUTER TIE ROD
END ................................32TIE ROD END
REMOVAL - OUTER TIE ROD END..........32
INSTALLATION - OUTER TIE ROD END......33
LINKAGE - INDEPENDENT
FRONT SUSPENSION
DIAGNOSIS AND TESTING - OUTER TIE ROD
END
NOTE: If the outer tie rod end is equipped with a
lubrication fitting, grease the joint then road test
the vehicle before performing test.
(1) Raise the front of the vehicle. Place safety floor
stands under both lower control arms as far outboard
as possible. Lower the vehicle to allow the stands to
support some or all of the vehicle weight.
(2) Remove the front tires.
(3) Mount a dial indicator solidly to the vehicle
steering knuckle and then zero the dial indicator.
(4) Position indicator plunger on the topside of the
outer tie rod end.
NOTE: The dial indicator plunger must be perpen-
dicular to the machined surface of the outer tie rod
end.
(5) Position a pry bar in order to pry downwards
on the outer tie rod end.
(6) If the travel exceeds 0.5 mm (0.020 in.), replace
the outer tie rod end (Refer to 19 - STEERING/
LINKAGE/TIE ROD END - REMOVAL).
(7) If the outer tie rod end is within specs reinstall
the front tires (Refer to 22 - TIRES/WHEELS/
WHEELS - STANDARD PROCEDURE).
TIE ROD END
REMOVAL - OUTER TIE ROD END
NOTE: Do not twist the boot anytime during
removal or installation.
(1) Loosen the jam nut.
(2) Remove the outer tie rod end nut from the ball
stud.
(3) Separate the tie rod ball stud from the knuckle
with Remover 8677 (Fig. 1).
(4) Unthread the outer tie rod end from the inner
tie rod.
Fig. 1 TIE ROD SEPARATION
1 - TIE ROD END
2 - SPECIAL TOOL 8677
19 - 32 LINKAGE - INDEPENDENT FRONT SUSPENSIONDR

LINKAGE - LINK/COIL
TABLE OF CONTENTS
page page
LINKAGE - LINK/COIL
DESCRIPTION.........................34
STANDARD PROCEDURE - LUBRICATION....34
SPECIFICATIONS
TORQUE CHART......................35
SPECIAL TOOLS
STEERING LINKAGE...................35
DAMPER
REMOVAL.............................36
INSTALLATION.........................36
DRAG LINK
REMOVAL.............................36INSTALLATION.........................36
PITMAN ARM
REMOVAL.............................36
INSTALLATION.........................37
TIE ROD END
REMOVAL.............................37
INSTALLATION.........................37
TRACK BAR
REMOVAL.............................38
INSTALLATION.........................38
LINKAGE - LINK/COIL
DESCRIPTION
The steering linkage is comprised of a tie rod end, tie
rod, drag link, steering damper and pitman arm (Fig. 1).
CAUTION: If any steering components are replaced
or serviced an alignment must be performed.
NOTE: To avoid damaging ball stud seals, use
Puller C-3894±A or an appropriate puller to remove
tie rod ends (Fig. 2).
STANDARD PROCEDURE - LUBRICATION
Periodic lubrication of the steering system compo-
nents is required. Refer to Lubrication And Mainte-
nance for the recommended maintenance schedule.
The following components must be lubricated:
²Tie rod
²Tie rod end
²Drag link
Fig. 1 LINK/COIL FRONT SUSPENSION
1 - STABILIZER BAR
2 - PITMAN ARM
3 - STEERING GEAR
4 - STABILIZER LINK
5 - TIE ROD ENDS
6 - LOWER SUSPENSION ARMS
7 - DRAG LINK
8 - TRACK BAR
9 - DAMPER
10 - UPPER SUSPENSION ARM
Fig. 2 Ball Stud Puller
1 - CLAMP
2 - ADJUSTMENT SLEEVE
3 - PULLER TOOL C-3894±A
4 - SEAL
5 - TIE-ROD END
19 - 34 LINKAGE - LINK/COILDR

PUMP
TABLE OF CONTENTS
page page
PUMP
DESCRIPTION.........................39
OPERATION...........................40
DIAGNOSIS AND TESTING - PUMP LEAKAGE . 40
STANDARD PROCEDURE
STANDARD PROCEDURE - POWER
STEERING PUMP - INITIAL OPERATION....40
STANDARD PROCEDURE - FLUSHING
POWER STEERING SYSTEM............40
REMOVAL
REMOVAL - GAS......................41
REMOVAL - DIESEL...................41
INSTALLATION
INSTALLATION - GAS..................42
INSTALLATION - DIESEL................42
SPECIFICATIONS
TORQUE CHART......................42
FLUID
DESCRIPTION.........................43
STANDARD PROCEDURE - POWER
STEERING FLUID LEVEL CHECKING......43
FLUID COOLER
REMOVAL.............................43
INSTALLATION.........................43
HOSES - I.F.S.
REMOVAL
REMOVAL - RETURN HOSE - GEAR TO
COOLER............................44
REMOVAL - PRESSURE HOSE...........44
REMOVAL - RETURN HOSE - RESERVOIR
TO COOLER.........................44INSTALLATION
INSTALLATION - RETURN HOSE - GEAR TO
COOLER............................44
INSTALLATION - PRESSURE HOSE.......44
INSTALLATION - RETURN HOSE -
RESERVOIR TO COOLER...............44
HOSES - LINK/COIL
REMOVAL
REMOVAL - RETURN HOSE - GEAR TO
COOLER............................45
REMOVAL - PRESSURE HOSE...........45
REMOVAL - RETURN HOSE - RESERVOIR
TO COOLER.........................45
INSTALLATION
INSTALLATION - RETURN HOSE - GEAR TO
COOLER............................45
INSTALLATION - PRESSURE HOSE.......45
INSTALLATION - RETURN HOSE -
RESERVOIR TO COOLER...............45
POWER STEERING PRESSURE SWITCH
DESCRIPTION.........................46
OPERATION...........................46
REMOVAL - 3.7L & 5.7L..................46
INSTALLATION - 3.7L & 5.7L...............46
PULLEY
REMOVAL.............................47
INSTALLATION.........................47
RESERVOIR
REMOVAL.............................47
INSTALLATION.........................47
PUMP
DESCRIPTION
CAUTION: MOPARTATF+4 is to be used in the
power steering system. No other power steering or
automatic transmission fluid is to be used in the
system. Damage may result to the power steering
pump and system if any other fluid is used, and do
not overfill.The pump is connected to the steering gear via the
pressure hose and the return hose. The pump shaft
has a pressed-on pulley that is belt driven by the
crankshaft pulley.
All vehicles are equipped with a power steering
fluid cooler.
NOTE: Power steering pumps are not interchange-
able with pumps installed on other vehicles.
DRPUMP 19 - 39