1998 DODGE RAM 1500 Power control

Accelerator Pedal Position Sensor Not Mounted To Engine
(1) Attach cable to Accelerator Pedal Position Sen-
sor (APPS). Refer to APPS (Diesel) Removal / Instal-
lation.
(2) Push cable housing into rubber grommet and
through opening in dash panel.
(3) From inside vehicle, install clip holding cable
to dashpanel (Fig. 35).
(4) From inside vehicle, slide throttle cable core
wire into opening in top of pedal arm.
(5) Push cable retainer (clip) into pedal arm open-
ing until it snaps in place.
(6) Before starting engine, operate accelerator
pedal to check for any binding.
(7) If necessary, use DRB IIItScan Tool to erase
any APPS Diagnostic Trouble Codes (DTC's) from
Engine Control Module (ECM).
PTO SWITCH
DESCRIPTION
This Engine Control Module (ECM) input is used
only on models equipped with aftermarket Power
Take Off (PTO) units.
OPERATION
This input is used only to tell the PCM (non-die-
sel), or ECM (diesel) that the aftermarket PTO
(Power Take Off) unit has been engaged. The PCM
(or ECM) will disable (temporarily shut down) cer-
tain OBD II diagnostic trouble codes when the PTO
unit is engaged.
Fig. 35 ACCELERATOR PEDAL MOUNTING
1 - ACCELERATOR CABLE
2 - PLASTIC RETAINER (CLIP)
3 - THROTTLE PEDAL ARM
4 - PEDAL / BRACKET ASSEMBLY
5 - CABLE CLIP
DRFUEL INJECTION - DIESEL 14 - 85
THROTTLE CONTROL CABLE (Continued)

DIAGNOSIS AND TESTING - POWER STEERING
FLOW AND PRESSURE
The following procedure is used to test the opera-
tion of the power steering system on the vehicle. This
test will provide the gallons per minute (GPM) or
flow rate of the power steering pump along with the
maximum relief pressure. Perform test any time a
power steering system problem is present. This test
will determine if the power steering pump or power
steering gear is not functioning properly. The follow-
ing pressure and flow test is performed using Power
Steering Analyzer Tool kit 6815 and (Fig. 2) Adapter
Kit 6893.
FLOW AND PRESSURE TEST
(1) Check the power steering belt to ensure it is in
good condition and adjusted properly.
(2) Connect pressure gauge hose from the Power
Steering Analyzer to adapter 6826.
(3) Connect tube 6825A to Power Steering Ana-
lyzer test valve end.
(4) Disconnect the high pressure hose from the
power steering pump.
(5) Connect the tube 6825A to the pump fitting.
(6) Connect the power steering hose from the
steering gear to the adapter 6826.
(7) Open the test valve completely.
(8) Start engine and let idle long enough to circu-
late power steering fluid through flow/pressure test
gauge and to get air out of the fluid. Then shut off
engine.(9) Check fluid level, add fluid as necessary. Start
engine again and let idle.
(10) Gauge should read below 862 kPa (125 psi), if
above, inspect the hoses for restrictions and repair as
necessary. The initial pressure reading should be in
the range of 345-552 kPa (50-80 psi).
(11) Increase the engine speed to 1500 RPM and
read the flow meter. If the flow rate (GPM) is below
specification, (refer to pump specification chart for
GPM) the pump should be replaced.
CAUTION: The following test procedure involves
testing maximum pump pressure output and flow
control valve operation. Do not leave valve closed
for more than three seconds as the pump could be
damaged.
(12) Close valve fully three times and record high-
est pressure indicated each time.All three read-
ings must be above specifications and within
345 kPa (50 psi) of each other.
²Pressures above specifications but not within
345 kPa (50 psi) of each other, replace pump.
²Pressures within 345 kPa (50 psi) of each other
but below specifications, replace pump.
(13) Open the test valve and turn the steering
wheel to the extreme left and right positions three
times against the stops. Record the highest pressure
reading at each position. Compare readings to the
pump specifications chart. If pressures readings are
not within 50 psi of each other, the gear is leaking
internally and must be replaced.
CAUTION: Do not force the pump to operate against
the stops for more than 2 to 3 seconds at a time
because, pump damage will result.PUMP SPECIFICATION
ENGINERELIEF PRESSURE
 65FLOW RATE
(GPM) AT 1500
RPM
1500
series11032 kPa
(1615   65 psi)3.1 - 3.5
2500 &
3500
series12400 kPa
(1800   50 psi)3.5 - 4.0
Fig. 2 Analyzer With Tube and Adapter
1 - TUBE
2 - ADAPTER FITTINGS
3 - ANALYZER
4 - GAUGE HOSE
19 - 4 STEERINGDR
STEERING (Continued)

INSTALLATION
NOTE: Before installing gear inspect bushings and
replace if worn or damaged.
NOTE: In the frame there is two holes for the
mounting of the steering gear one is slotted and
one is round, When tightening the gear to specifi-
cations make sure to tighten the mounting bolt with
the hole first to avoided movement of the steering
gear.
(1) Install the gear on the front crossmember and
tighten the mounting bolts to 319 N´m (235 ft. lbs.).
(Fig. 4) & (Fig. 3).
(2) Slide the shaft coupler onto the gear. Install
newpinch bolt and tighten to 49 N´m (36 ft. lbs.).
(3) Clean and dry the tie rod end studs and the
knuckle tapers.
(4) Install the tie rod ends into the steering knuck-
les and tighten the nuts to 61 N´m (45 ft. lbs.) thenan additional 90É. (Refer to 19 - STEERING/LINK-
AGE/TIE ROD END - INSTALLATION).
(5) Install the pressure power steering hose to the
steering gear and tighten to 32 N´m (23 ft. lbs.).
(Refer to 19 - STEERING/PUMP/HOSES - INSTAL-
LATION).
(6) Install the return power steering hose to the
steering gear and tighten to 71 N´m (52 ft. lbs.).
(Refer to 19 - STEERING/PUMP/HOSES - INSTAL-
LATION).
(7) Install the front skid plate (Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT SKID PLATE
- INSTALLATION).
(8) Install the tire and wheel assembly (Refer to 22
- TIRES/WHEELS/WHEELS - STANDARD PROCE-
DURE).
(9) Remove the support and lower the vehicle.
(10) Fill the system with fluid, (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
(11) Adjust the toe position. (Refer to 2 - SUSPEN-
SION/WHEEL ALIGNMENT - STANDARD PROCE-
DURE).
Fig. 3 STEERING GEAR 4X2
1-SWAYBAR
2 - STEERING GEAR
3 - LEFT OUTER TIE ROD END
4 - LOWER CONTROL ARMS
5 - LEFT INNER & RIGHT OUTER (TIE ROD ENDS)
Fig. 4 STEERING GEAR 4X4
1 - FRONT AXLE
2 - STEERING GEAR MOUNTING NUTS & BUSHINGS
19 - 18 GEAR - INDEPENDENT FRONT SUSPENSIONDR
GEAR - INDEPENDENT FRONT SUSPENSION (Continued)

OPERATION
Hydraulic pressure is provided for the power steer-
ing gear by the belt driven power steering pump (Fig.
1). The power steering pumps are constant flow rate
and displacement, vane-type pumps.
DIAGNOSIS AND TESTING - PUMP LEAKAGE
The pump is serviced as an assembly and should
not be disassembled. The plastic pump reservoir and
the reservoir o-rings can be replaced.
Check for leaks in the following areas:
²Pump shaft seal behind the pulley
²Pump to reservoir O-ring
²Reservoir cap
²Pressure and return lines
²Flow control valve fitting
STANDARD PROCEDURE
STANDARD PROCEDURE - POWER STEERING
PUMP - INITIAL OPERATION
WARNING: THE FLUID LEVEL SHOULD BE
CHECKED WITH ENGINE OFF TO PREVENT INJURY
FROM MOVING COMPONENTS.
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 steeringpump and system if any other fluid is used, and do
not overfill.
Wipe filler cap clean, then check the fluid level.
The dipstick should indicateCOLDwhen the fluid is
at normal temperature.
(1) Turn steering wheel all the way to the left
(2) Fill the pump fluid reservoir to the proper level
and let the fluid settle for at least two (2) minutes.
(3) Raise the front wheels off the ground.
(4) Slowly turn the steering wheel lock-to-lock 20
times with the engine off while checking the fluid
level.
NOTE: For vehicles with long return lines or oil
coolers turn wheel 40 times.
(5) Start the engine. With the engine idling main-
tain the fluid level.
(6) Lower the front wheels and let the engine idle
for two minutes.
(7) Turn the steering wheel in both direction and
verify power assist and quiet operation of the pump.
If the fluid is extremely foamy or milky looking,
allow the vehicle to stand a few minutes and repeat
the procedure.
CAUTION: Do not run a vehicle with foamy fluid for
an extended period. This may cause pump damage.
STANDARD PROCEDURE - FLUSHING POWER
STEERING SYSTEM
Flushing is required when the power steering/hy-
draulic booster system fluid has become contami-
nated. Contaminated fluid in the steering/booster
system can cause seal deterioration and affect steer-
ing gear/booster spool valve operation.
(1) Raise the front end of the vehicle off the
ground until the wheels are free to turn.
(2) Remove the return line from the pump.
NOTE: If vehicle is equipped with a hydraulic
booster remove both return lines from the pump.
(3) Plug the return line port/ports at the pump.
(4) Position the return line/lines into a large con-
tainer to catch the fluid.
(5) While an assistant is filling the pump reservoir
start the engine.
(6) With the engine running at idle turn the wheel
back and forth.
NOTE: Do not contact or hold the wheel against the
steering stops.
(7) Run a quart of fluid through the system then
stop the engine and install the return line/lines.
Fig. 1 POWER STEERING PUMP
1 - 3.7L & 4.7L (6 GROOVE)
PHENOLIC (PLASTIC TYPE) PULLEY
1 - 5.7L,5.9L & 8.0L (7 GROOVE)
PHENOLIC (PLASTIC TYPE) PULLEY
1 - 5.9L DIESEL (8 GROOVE)
STEEL PULLEY
2 - PUMP ASSEMBLY
3 - RESERVOIR
4 - CAP
19 - 40 PUMPDR
PUMP (Continued)

(4) Remove the support and lower the vehicle.
(5) Reconnect the return hose at the reservoir.
(6) Refill the power steering system,(Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
POWER STEERING PRESSURE
SWITCH
DESCRIPTION
A pressure sensing switch is used in the power
steering system. It is mounted on the high-pressure
steering hose (Fig. 9). This switch will be used with
both 3.7L and 5.7L engines. There is no pressure
switch used for the 4.7L or the 5.9L pump.
OPERATION
The switch is used on the 3.7L V-6 & 5.7L V-8
engines.
The power steering pressure switch provides an
input to the Powertrain Control Module (PCM). This
input is provided during periods of high steering
pump load and low engine rpm; such as during park-
ing maneuvers. The PCM increases the idle speed
through the Idle Air Control (IAC) motor. This is
done to prevent the engine from stalling under the
increased load.
When steering pump pressure exceeds 3275 kPa  
690 kPa (475 psi   100 psi), the Normally Closed
(NC) switch will open and the PCM will increase the
engine idle speed. This will prevent the engine from
stalling.
When pump pressure drops to approximately 1379
kPa (200 psi), the switch circuit will re-close and
engine idle speed will return to its previous setting.
REMOVAL - 3.7L & 5.7L
The power steering pressure switch is installed in
the power steering high-pressure hose (Fig. 9).
(1) Disconnect electrical connector from power
steering pressure switch.(2) Place a small container or shop towel beneath
switch to collect any excess fluid.
(3) Remove switch. Use back-up wrench on power
steering line to prevent line bending.
INSTALLATION - 3.7L & 5.7L
This switch is used only with the 3.7L V±6 and the
5.7L V-8 engines.
(1) Install power steering switch into power steer-
ing line.
(2) Tighten to 8±11 N´m (70±100 in. lbs.) torque.
(3) Connect electrical connector to switch.
(4) Check power steering fluid and add as neces-
sary.
(5) Start engine and again check power steering
fluid. Add fluid if necessary.
Fig. 9 PRESSURE SWITCH
1 - POWER STEERING PULLEY
2 - POWER STEERING PUMP HOUSING
3 - POWER STEERING FLUID RESERVOIR
4 - RETURN HOSE
5 - HIGH PRESSURE HOSE WITH PRESSURE SWITCH
19 - 46 PUMPDR
HOSES - LINK/COIL (Continued)

MANUAL TRANSMISSION - NV4500
TABLE OF CONTENTS
page page
MANUAL TRANSMISSION - NV4500
DESCRIPTION.........................43
OPERATION...........................43
DIAGNOSIS AND TESTING................44
REMOVAL.............................44
DISASSEMBLY.........................46
CLEANING............................62
INSPECTION..........................62
ASSEMBLY............................63
INSTALLATION.........................80
SPECIFICATIONS.......................81
SPECIAL TOOLS.......................81ADAPTER HOUSING SEAL
REMOVAL.............................85
INSTALLATION.........................85
EXTENSION HOUSING SEAL
REMOVAL.............................85
INSTALLATION.........................85
SHIFT MECHANISM
REMOVAL.............................86
INSTALLATION.........................87
SHIFT COVER
REMOVAL.............................87
INSTALLATION.........................87
MANUAL TRANSMISSION -
NV4500
DESCRIPTION
The NV4500 is a five speed constant mesh manual
transmission. All gear ranges including reverse are
synchronized. Fifth gear is an overdrive range. The
transmission has a cast iron gear case and aluminum
shift cover.
Two versions are used, a standard duty for 5.7L
applications and a heavy duty for V10 and Cummins
diesel applications. Main difference is a larger diam-
eter input shaft, for the heavy duty model.
Tapered roller bearings support the drive gear,
mainshaft and countershaft in the gear case. Roller
bearings in the drive gear support the forward end of
the mainshaft. The mainshaft gears are all supported
on caged type roller bearings. Drive gear thrust reac-
tion is controlled by a needle type thrust bearing.
The bearing is located at the forward end of the
mainshaft.
The transmission is a top loader style. The shift
lever is located in a shifter tower which is bolted to
the shift cover and operates the shift forks and rails
directly. The shift forks and rails are all located
within the aluminum cover which is bolted to the top
of the gear case.
IDENTIFICATION
The transmission identification tag is attached to
the driver side PTO cover (Fig. 1).
The tag provides the transmission model number,
build date and part number. Be sure to reinstall the
I.D. tag if removed during service. The information
on the tag is essential to correct parts ordering.
OPERATION
The manual transmission receives power through
the clutch assembly from the engine. The clutch disc
is splined to the transmission input shaft and is
turned at engine speed at all times that the clutch is
engaged. The input shaft is connected to the trans-
mission countershaft through the mesh of fourth
speed gear on the input shaft and the fourth counter-
shaft gear. At this point all the transmission gears
are spinning.
Fig. 1 IDENTIFICATION TAG LOCATION
1 - PTO COVER
2 - I.D. TAG
DRMANUAL TRANSMISSION - NV4500 21 - 43

AUTOMATIC TRANSMISSION -
48RE
DESCRIPTION
The 48RE (Fig. 1) is a four speed fully automatic
transmissions with an electronic governor. The 48RE
is equipped with a lock-up clutch in the torque con-
verter. First through third gear ranges are provided
by the clutches, bands, overrunning clutch, and plan-
etary gear sets in the transmission. Fourth gear
range is provided by the overdrive unit that contains
an overdrive clutch, direct clutch, planetary gear set,
and overrunning clutch.
The transmission contains a front, rear, and direct
clutch which function as the input driving compo-
nents. It also contains the kickdown (front) and thelow/reverse (rear) bands which, along with the over-
running clutch and overdrive clutch, serve as the
holding components. The driving and holding compo-
nents combine to select the necessary planetary gear
components, in the front, rear, or overdrive planetary
gear set, transfer the engine power from the input
shaft through to the output shaft.
The valve body is mounted to the lower side of the
transmission and contains the valves to control pres-
sure regulation, fluid flow control, and clutch/band
application. The oil pump is mounted at the front of
the transmission and is driven by the torque con-
verter hub. The pump supplies the oil pressure nec-
essary for clutch/band actuation and transmission
lubrication.
21 - 132 AUTOMATIC TRANSMISSION - 48REDR

IDENTIFICATION
Transmission identification numbers are stamped
on the left side of the case just above the oil pan gas-
ket surface (Fig. 2). Refer to this information when
ordering replacement parts.
GEAR RATIOS
The 48RE gear ratios are:
1st.................................2.45:1
2nd................................1.45:1
3rd................................1.00:1
4th.................................0.69:1
Rev.................................2.20:1
OPERATION
The application of each driving or holding compo-
nent is controlled by the valve body based upon the
manual lever position, throttle pressure, and gover-
nor pressure. The governor pressure is a variable
pressure input to the valve body and is one of the
signals that a shift is necessary. First through fourth
gear are obtained by selectively applying and releas-
ing the different clutches and bands. Engine power is
thereby routed to the various planetary gear assem-
blies which combine with the overrunning clutch
assemblies to generate the different gear ratios. The
torque converter clutch is hydraulically applied and
is released when fluid is vented from the hydraulic
circuit by the torque converter control (TCC) solenoid
on the valve body. The torque converter clutch is con-
trolled by the Powertrain Control Module (PCM). The
torque converter clutch engages in fourth gear, and
in third gear under various conditions, such as when
the O/D switch is OFF, when the vehicle is cruising
on a level surface after the vehicle has warmed up.
The torque converter clutch can also be engaged in
the MANUAL SECOND gear position if high trans-
mission temperatures are sensed by the PCM. The
torque converter clutch will disengage momentarily
when an increase in engine load is sensed by the
PCM, such as when the vehicle begins to go uphill or
the throttle pressure is increased. The torque con-
verter clutch feature increases fuel economy and
reduces the transmission fluid temperature.
Since the overdrive clutch is applied in fourth gear
only and the direct clutch is applied in all ranges
except fourth gear, the transmission operation for
park, neutral, and first through third gear will be
described first. Once these powerflows are described,
the third to fourth shift sequence will be described.
1 - TORQUE CONVERTER 10 - OVERDRIVE CLUTCH
2 - INPUT SHAFT 11 - DIRECT CLUTCH
3 - OIL PUMP 12 - PLANETARY GEAR
4 - FRONT BAND 13 - INTERMEDIATE SHAFT
5 - FRONT CLUTCH 14 - OVERDRIVE OVERRUNNING CLUTCH
6 - REAR CLUTCH 15 - DIRECT CLUTCH SPRING
7 - PLANETARIES 16 - OVERDRIVE PISTON RETAINER
8 - REAR BAND 17 - OIL PAN
9 - OVERRUNNING CLUTCH 18 - VALVE BODY
Fig. 2 Transmission Part Number And Serial
Number Location
1 - PART NUMBER
2 - BUILD DATE
3 - SERIAL NUMBER
21 - 134 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)