1998 DODGE RAM 1500 transfer

OPERATION
Exhaust gas pressure and energy drive the tur-
bine, which in turn drives a centrifugal compressor
that compresses the inlet air, and forces the air into
the engine through the charge air cooler and plumb-
ing. Since heat is a by-product of this compression,
the air must pass through a charge air cooler to cool
the incoming air and maintain power and efficiency.
Increasing air flow to the engine provides:
²Improved engine performance
²Lower exhaust smoke density
²Improved operating economy
²Altitude compensation
²Noise reduction.
The turbocharger also uses a wastegate (Fig. 16),
which regulates intake manifold air pressure and
prevents over boosting at high engine speeds. When
the wastegate valve is closed, all of the exhaust gases
flow through the turbine wheel. As the intake mani-
fold pressure increases, the wastegate actuator opens
the valve, diverting some of the exhaust gases away
from the turbine wheel. This limits turbine shaft
speed and air output from the impeller.
The turbocharger is lubricated by engine oil that is
pressurized, cooled, and filtered. The oil is delivered
to the turbocharger by a supply line that is tapped
into the oil filter head. The oil travels into the bear-
ing housing, where it lubricates the shaft and bear-
ings (Fig. 17). A return pipe at the bottom of the
bearing housing, routes the engine oil back to the
crankcase.
The most common turbocharger failure is bearing
failure related to repeated hot shutdowns with inad-
equate ªcool-downº periods. A sudden engine shut
down after prolonged operation will result in the
transfer of heat from the turbine section of the tur-
bocharger to the bearing housing. This causes the oil
to overheat and break down, which causes bearing
and shaft damage the next time the vehicle is
started.
Letting the engine idle after extended operation
allows the turbine housing to cool to normal operat-
ing temperature. The following chart should be used
as a guide in determining the amount of engine idle
time required to sufficiently cool down the turbo-
charger before shut down, depending upon the type
of driving and the amount of cargo.
Fig. 16 Wastegate Operation
1 - SIGNAL LINE
2 - EXHAUST BYPASS VALVE
3 - WASTEGATE
4 - EXHAUST
5 - TURBINE
DREXHAUST SYSTEM 11 - 13
TURBOCHARGER (Continued)

(9) Remove the turbocharger and gasket from the
exhaust manifold.
(10) If the turbocharger is not to be installed
immediately, cover the opening to prevent material
from entering into the manifold.
(11) If replacing the turbocharger, transfer the tur-
bocharger oil supply fitting to the new assembly.
Tighten fitting to 36 N´m (27 ft. lbs.).
(12) Clean and inspect the sealing surface.
CAUTION: The turbocharger is only serviced as an
assembly. Do not attempt to repair the turbocharger
as turbocharger and/or engine damage can result.
CLEANING
WARNING: To prevent damage or personal injury,
do not use a combustable cleaner to clean the tur-
bocharger.
Clean the turbocharger and exhaust manifold
mounting surfaces with a suitable scraper.
INSPECTION
Visually inspect the turbocharger and exhaust
manifold gasket surfaces. Replace stripped or eroded
mounting studs.
(1) Visually inspect the turbocharger for cracks.
The following cracks are NOT acceptable:
²Cracks in the turbine and compressor housing
that go completely through.
²Cracks in the mounting flange that are longer
than 15 mm (0.6 in.).
²Cracks in the mounting flange that intersect
bolt through-holes.
²Two (2) Cracks in the mounting flange that are
closer than 6.4 mm (0.25 in.) together.
(2) Visually inspect the impeller and compressor
wheel fins for nicks, cracks, or chips. Note: Some
impellers may have a factory placed paint mark
which, after normal operation, appears to be a crack.
Remove this mark with a suitable solvent to verify
that it is not a crack.
(3) Visually inspect the turbocharger compressor
housing for an impeller rubbing condition (Fig. 20).
Replace the turbocharger if the condition exists.
(4) Measure the turbocharger axial end play:
(a) Install a dial indicator as shown in (Fig. 21).
Zero the indicator at one end of travel.
(b) Move the impeller shaft fore and aft and
record the measurement. Allowable end play is
0.026 mm (0.0001 in.) MIN. and 0.127 mm (0.005
in.) MAX. If the recorded measurement falls out-
side these parameters, replace the turbocharger
assembly.(5) Measure the turbocharger bearing radial clear-
ance:
(a) Insert a narrow blade or wire style feeler
gauge between the compressor wheel and the hous-
ing (Fig. 22).
(b) Gently push the compressor wheel toward
the housing and record the clearance.
(c) With the feeler gauge in the same location,
gently push the compressor wheel away from the
housing and again record the clearance.
(d) Subtract the smaller clearance from the
larger clearance. This is the radial bearing clear-
ance.
(e) Allowable radial bearing clearance is 0.33
mm (0.013 in.) MIN. and 0.50 mm (0.020 in.) MAX.
If the recorded measurement falls outside these
specifications, replace the turbocharger assembly.
INSTALLATION
(1) Install the turbocharger. Apply anti-seize to the
studs and then tighten the turbocharger mounting
nuts to 43 N´m (32 ft. lbs.) torque.
Fig. 20 Inspect Compressor Housing for Impeller
Rubbing Condition
Fig. 21 Measure Turbocharger Axial End Play
DREXHAUST SYSTEM 11 - 15
TURBOCHARGER (Continued)

FRAMES & BUMPERS
TABLE OF CONTENTS
page page
BUMPERS
SPECIFICATIONS - TORQUE...............1
FRONT AIR DAM
REMOVAL.............................2
INSTALLATION..........................2
FRONT BUMPER
REMOVAL.............................2
INSTALLATION..........................2
FRONT FASCIA
REMOVAL.............................2
INSTALLATION..........................3
REAR BUMPER
REMOVAL.............................3
INSTALLATION..........................4
FRAME
WARNING
SAFETY PRECAUTIONS AND WARNINGS . . . 4
STANDARD PROCEDURE
STANDARD PROCEDURE - LIGHT DUTY
FRONT FRAME RAIL TIP REPLACEMENT....4
STANDARD PROCEDURE - HYDROFORM
FENDER RAIL REPAIR.................11
STANDARD PROCEDURE - REAR FRAME
H-SECTION REPLACEMENT.............13SPECIFICATIONS
SPECIFICATIONS - WELD PROCESS......15
SPECIFICATIONS - FRAME DIMENSIONS . . . 16
SPECIFICATIONS - TORQUE............22
FRONT CROSSMEMBER
REMOVAL.............................22
INSTALLATION.........................22
FRONT SKID PLATE
REMOVAL.............................23
INSTALLATION.........................23
FRONT TOW HOOK ASSEMBLY
REMOVAL.............................23
INSTALLATION.........................23
TRANSMISSION CROSSMEMBER
REMOVAL.............................24
INSTALLATION.........................24
TRAILER HITCH
REMOVAL.............................25
INSTALLATION.........................25
TRANSFER CASE SKID PLATE
REMOVAL.............................26
INSTALLATION.........................26
BUMPERS
SPECIFICATIONS - TORQUE
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Front bumper center bracket nuts 95 70 Ð
Front bumper stud plate nuts 95 70 Ð
License plate hitch reinforcement bolts 54 40 Ð
Rear bumper support bracket stud plate nuts 54 40 Ð
Rear bumper support bracket to hitch bolts 54 40 Ð
Rear bumper to hitch bolts 54 40 Ð
DRFRAMES & BUMPERS 13 - 1

SPECIFICATIONS - TORQUE
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Cab mount bolts 81 60 Ð
Cargo box bolts 108 80 Ð
Front crossmember bolts - 2WD (light duty only) 61 45 Ð
Front crossmember bolts - 2WD (heavy duty only) 75 55 Ð
Front crossmember bolts - 4WD (light duty only) 102 75 Ð
Front skid plate bolts 34 25 Ð
Lower bumper support bracket bolt 54 40 Ð
Radiator crossmember bolts - lower 28 21 Ð
Radiator crossmember bolts - upper 28 21 Ð
Rear crossmember (light duty only) 102 75 Ð
Rear crossmember (heavy duty only) 115 85 Ð
Rear spring shackle bolts 163 120 Ð
Spare tire winch bolts 41 30 Ð
Trailer hitch reinforcement bracket bolt 170 125 Ð
Transfercase skid plate bolts 34 25 Ð
Transercase skid plate crossmember bolts 34 25 Ð
Transmission mount to crossmember nuts 54 40 Ð
FRONT CROSSMEMBER
REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Remove the front skid plate, if equipped. (Refer
to 13 - FRAME & BUMPERS/FRAME/FRONT SKID
PLATE - REMOVAL)
(3) Remove the bolts and remove the crossmember.
(Fig. 28) or (Fig. 29)
INSTALLATION
(1) Install the crossmember.
(2) Install the bolts;
²On light duty 2WD vehicles, tighten the bolts to
61 N´m (45 ft. lbs.).
²On light duty 4WD vehicles, tighten the bolts to
102 N´m (75 ft. lbs.).
²On heavy duty 2WD vehicles, tighten the bolts
to 75 N´m (55 ft. lbs.).
(3) Install the front skid plate, if equipped. (Refer
to 13 - FRAME & BUMPERS/FRAME/FRONT SKID
PLATE - INSTALLATION)
Fig. 28 FRONT CROSSMEMBER - 2WD
1 - CROSSMEMBER
2 - BOLTS (2 PER SIDE)
13 - 22 FRAMES & BUMPERSDR
FRAME (Continued)

TRANSMISSION
CROSSMEMBER
REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Remove the transfercase skid plate, if
equipped. (Refer to 13 - FRAME & BUMPERS/
FRAME/TRANSFER CASE SKID PLATE -
REMOVAL)
(3) Support the transmission with a suitable lifting
device.
(4) Remove the transmission mount nuts. (Fig. 33)
or (Fig. 34)
(5) Remove the bolts and remove the crossmember.
INSTALLATION
(1) Install the crossmember and install the bolts.
²On light duty vehicles, tighten the bolts to 102
N´m (75 ft. lbs.).
²On heavy duty vehicles, tighten the bolts to 115
N´m (85 ft. lbs.).
(2) Install the transmission mount nuts and
tighten to 54 N´m (40 ft. lbs.).(3) Remove the transmission support.
(4) Install the transfercase skid plate. (Refer to 13
- FRAME & BUMPERS/FRAME/TRANSFER CASE
SKID PLATE - INSTALLATION)
Fig. 32 FRONT TOW HOOK ASSEMBLY ± HEAVY
DUTY
1 - BOLTS (4 PER HOOK)
2 - HEAVY DUTY TOW HOOKS (2)
3 - BUMPER CENTER SUPPORT BRACKETS
Fig. 33 REAR CROSSMEMBER - 2WD
1 - TRANSMISSION MOUNT
2 - REAR CROSSMEMBER
3 - TRANSMISSION MOUNT NUTS (2)
4 - CROSSMEMBER BOLTS (2 PER SIDE)
Fig. 34 REAR CROSSMEMBER - 4WD
1 - TRANSMISSION MOUNT
2 - TORSION BAR
3 - CROSSMEMBER BOLTS (3 PER SIDE)
4 - REAR CROSSMEMBER
5 - TRANSMISSION MOUNT NUTS (2)
13 - 24 FRAMES & BUMPERSDR
FRONT TOW HOOK ASSEMBLY (Continued)

TRANSFER CASE SKID PLATE
REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Support the skid plate and remove the bolts.
(Fig. 37)
(3) Remove the skid plate.
(4) Support the skid plate crossmember and
remove the bolts.
(5) Remove the skid plate crossmember.
INSTALLATION
(1) Install the skid plate crossmember and install
the bolts.
(2) Tighten the bolts to 34 N´m (25 ft. lbs.).
(3) Install the skid plate and install the bolts.
(4) Tighten the bolts to 34 N´m (25 ft. lbs.).
Fig. 37 TRANSFER CASE SKID PLATE
1 - CROSSMEMBER BOLTS (4)
2 - SKID PLATE CROSSMEMBER
3 - SKID PLATE
4 - SKID PLATE BOLTS (4)
Fig. 36 TRAILER HITCH ± HEAVY DUTY
1 - LOCATING TAB HOLE
2 - LOCATING PIN HOLE
3 - U-NUTS (2)
4 - BUMPER SUPPORT BRACKETS5 - HITCH
6 - HITCH TO FRAME NUTS (2)
7 - BUMPER BRACKET BOLTS (4)
8 - HITCH BOLTS (6)
13 - 26 FRAMES & BUMPERSDR
TRAILER HITCH (Continued)

FUEL DELIVERY - DIESEL
TABLE OF CONTENTS
page page
FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM.....45
STANDARD PROCEDURE
STANDARD PROCEDURES - WATER
DRAINING AT FUEL FILTER..............47
STANDARD PROCEDURES - CLEANING
FUEL SYSTEM PARTS.................47
STANDARD PROCEDURE - FUEL SYSTEM
PRIMING............................47
SPECIFICATIONS
FUEL INJECTOR FIRING ORDER - DIESEL . 48
TORQUE - FUEL SYSTEM - DIESEL
ENGINE.............................48
SPECIAL TOOLS
DIESEL FUEL SYSTEM.................49
FUEL FILTER / WATER SEPARATOR
DESCRIPTION.........................50
OPERATION...........................50
REMOVAL.............................50
INSTALLATION.........................50
FUEL HEATER
DESCRIPTION.........................51
OPERATION...........................51
DIAGNOSIS AND TESTING - FUEL HEATER . . . 52
REMOVAL
REMOVAL/INSTALLATION...............52
FUEL HEATER RELAY
DESCRIPTION.........................52
OPERATION...........................52
REMOVAL.............................52
INSTALLATION.........................53
FUEL INJECTION PUMP
DESCRIPTION.........................53
OPERATION...........................53
DIAGNOSIS AND TESTING - FUEL INJECTION
PUMP TIMING........................53
REMOVAL.............................54
INSTALLATION.........................55
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION.........................57
OPERATION...........................57
REMOVAL
REMOVAL/INSTALLATION...............57FUEL LINES
DESCRIPTION.........................57
OPERATION...........................57
DIAGNOSIS AND TESTING - HIGH-
PRESSURE FUEL LINE LEAKS...........58
REMOVAL.............................58
INSTALLATION.........................60
FUEL PRESSURE SENSOR
DESCRIPTION.........................60
OPERATION...........................60
REMOVAL.............................60
INSTALLATION.........................61
FUEL PRESSURE LIMITING VALVE
DESCRIPTION.........................61
OPERATION...........................61
REMOVAL.............................61
INSTALLATION.........................61
FUEL TANK
DESCRIPTION - DIESEL..................62
REMOVAL - DIESEL.....................62
INSTALLATION - DIESEL.................62
FUEL TANK MODULE
DESCRIPTION.........................63
OPERATION...........................63
REMOVAL.............................63
INSTALLATION.........................64
FUEL TRANSFER PUMP
DESCRIPTION.........................64
OPERATION...........................64
REMOVAL.............................64
INSTALLATION.........................65
CASCADE OVERFLOW VALVE
DESCRIPTION.........................66
OPERATION...........................66
REMOVAL
REMOVAL/INSTALLATION...............66
WATER IN FUEL SENSOR
DESCRIPTION.........................66
OPERATION...........................66
REMOVAL.............................66
FUEL DRAIN CIRCUIT
OPERATION...........................67
14 - 44 FUEL DELIVERY - DIESELDR

FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM
The fuel system used on the Cummins engine is an
electronically controlled, Bosch HPCR (High-Pressure
Common Rail) system. The HPCR system consists of
five main components:
²Electric Fuel Transfer (lift) Pump
²Fuel Pump/Gear Pump (attached to fuel injec-
tion pump)
²High-Pressure Fuel Injection Pump
²Fuel Injection Rail
²Fuel Injectors
Also to be considered as part of the overall fuel
system are:
²Accelerator Pedal
²Air Cleaner Housing/Element
²Fuel Drain Manifold (passage)
²Fuel Drain Valve (at filter)
²Fuel Filter/Water Separator
²Fuel Heater
²Fuel Heater Relay
²Fuel Level (gauge) Sending Unit
²Fuel Pressure Limiting Valve
²Fuel Tank
²Fuel Tank Module (containing fuel gauge send-
ing unit and separate fuel filter located at bottom of
tank module)
²Fuel Tank Filler/Vent Tube Assembly
²Fuel Tank Filler Tube Cap
²Fuel Tubes/Lines/Hoses
²High-Pressure Fuel Injector Lines
²In-Tank Fuel Filter (at bottom of fuel tank mod-
ule)
²Low-Pressure Fuel Supply Lines
²Low-Pressure Fuel Return Line
²Overflow Valve
²Quick-Connect Fuel Line Fittings
²Throttle Cable
²Water Draining (maintenance)
²Water-In-Fuel (WIF) Sensor
The fuel injection pump supplies high pressure to
the fuel rail independent of engine speed. This high
pressure fuel is then accumulated in the fuel rail.
High pressure fuel is constantly supplied to the injec-
tors by the fuel rail. The Engine Control Module
(ECM) controls the fueling and timing of the engine
by actuating the injectors.Fuel enters the system from the electric fuel trans-
fer (lift) pump, which is attached to the fuel filter
assembly. Fuel is forced through the fuel filter ele-
ment and then enters the Fuel Pump/Gear Pump,
which is attached to the rear of the fuel injection
pump. The Fuel Pump/Gear Pump is a low-pressure
pump and produce pressures ranging from 551.5 kpa
(80 psi) to 1241 kpa (180) psi. Fuel then enters the
fuel injection pump. Low pressure fuel is then sup-
plied to the FCA (Fuel Control Actuator).
The FCA is an electronically controlled solenoid
valve. The ECM controls the amount of fuel that
enters the high-pressure pumping chambers by open-
ing and closing the FCA based on a demanded fuel
pressure. The FPS (Fuel Pressure Sensor) on the fuel
rail monitors the actual fuel pressure and provides it
as an input to the ECM. When the actuator is
opened, the maximum amount of fuel is being sup-
plied to the fuel injection pump. Any fuel that does
not enter the injection pump is directed to the over-
flow valve. The overflow valve regulates how much
excess fuel is used for lubrication of the pump and
how much is returned to the tank through the drain
manifold.
Fuel entering the injection pump is pressurized to
between 300-1600 bar (4351-23,206 psi) by three
radial pumping chambers. The pressurized fuel is
then supplied to the fuel rail.
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 160,000 KPA (23,206
PSI). USE EXTREME CAUTION WHEN INSPECTING
FOR HIGH-PRESSURE FUEL LEAKS. INSPECT FOR
HIGH-PRESSURE FUEL LEAKS WITH A SHEET OF
CARDBOARD. HIGH FUEL INJECTION PRESSURE
CAN CAUSE PERSONAL INJURY IF CONTACT IS
MADE WITH THE SKIN.
Certain fuel system components can be found in
(Fig. 1), or (Fig. 2).
DRFUEL DELIVERY - DIESEL 14 - 45