1998 DODGE RAM 1500 Transmission shaft

CONDITION POSSIBLE CAUSES CORRECTION
Clutch disc facing contaminated with
oil, grease, or clutch fluid.1. Leak at rear main engine seal or
transmission input shaft seal.1. Replace appropriate seal.
2. Excessive amount of grease
applied to the input shaft splines.2. Remove grease and apply the
correct amount of grease.
3. Road splash, water entering
housing.3. Replace clutch disc. Clean clutch
cover and reuse if in good condition.
4. Slave cylinder leaking. 4. Replace hydraulic clutch linkage.
Clutch is running partially
disengaged.1. Release bearing sticking or
binding and does not return to the
normal running position.1. Verify failure. Replace the release
bearing and transmission front
bearing retainer as necessary.
Flywheel below minimum thickness
specification.1. Improper flywheel machining.
Flywheel has excessive taper or
excessive material removal.1. Replace flywheel.
Clutch disc, cover and/or diaphragm
spring warped or distorted.1. Rough handling. Impact bent
cover, spring, or disc.1. Replace disc or cover as
necessary.
2. Improper bolt tightening
procedure.2. Tighten clutch cover using proper
procedure.
Facing on flywheel side of disc torn,
gouged, or worn.1. Flywheel surface scored or
nicked.1. Correct surface condition if
possible. Replace flywheel and disc
as necessary.
2. Clutch disc sticking or binding on
transmission input shaft.2. Inspect components and
correct/replace as necessary.
Clutch disc facing burnt. Flywheel
and cover pressure plate surfaces
heavily glazed.1. Frequent operation under high
loads or hard acceleration
conditions.1. Correct condition of flywheel and
pressure plate surface. Replace
clutch cover and disc. Alert driver to
problem cause.
2. Driver frequently rides (slips)
clutch. Results in rapid wear and
overheating of disc and cover.2. Correct condition of flywheel and
pressure plate surface. Replace
clutch cover and disc. Alert driver to
problem cause.
Clutch disc binds on input shaft
splines.1. Clutch disc hub splines damaged
during installation.1. Clean, smooth, and lubricate hub
splines if possible. Replace disc if
necessary.
2. Input shaft splines rough,
damaged, or corroded.2. Clean, smooth, and lubricate
shaft splines if possible. Replace
input shaft if necessary.
Clutch disc rusted to flywheel and/or
pressure plate.1. Clutch not used for an extended
period of time (e.g. long term
vehicle storage).1. Sand rusted surfaces with 180
grit sanding paper. Replace clutch
cover and flywheel if necessary.
DRCLUTCH 6 - 3
CLUTCH (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
Partial engagement of clutch disc.
One side of disc is worn and the
other side is glazed and lightly
worn.1. Clutch pressure plate position
incorrect.1. Replace clutch disc and cover.
2. Clutch cover, spring, or release
fingers bent or distorted.2. Replace clutch disc and cover.
3. Clutch disc damaged or
distorted.2. Replace clutch disc.
4. Clutch misalignment. 4. Check alignment and runout of
flywheel, disc, pressure plate, andùr
clutch housing. Correct as
necessary.
SPECIFICATIONS
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Slave Cylinder Nuts 23 17 -
Clutch Master Cylinder
Nuts28 21 -
Pressure Plate Bolts - V6
&V850 37 -
Pressure Plate Bolts - V10 30 22.5 -
Pressure Plate Bolts -
Diesel30 22.5 -
Release Bearing Pivot 23 17 -
Flywheel Bolts 95 70 -
CLUTCH DISC
REMOVAL
(1) Support engine with wood block and adjustable
jack stand, to prevent strain on engine mounts.
(2) Remove transmission and transfer case, if
equipped.
(3) If pressure plate will be reused, mark the posi-
tion on flywheel with paint or scriber (Fig. 1). Also
note location marks on the pressure next to the bolt
holes. The mark will be a L or a circle with an X in
it.
(4) Insert clutch alignment tool through clutch disc
and into pilot bushing, to hold disc in place while
removing bolts.
(5) Loosen pressure plate bolts evenly, a few
threads at a time and in a diagonal pattern to pre-
vent warping the plate.
(6) Remove bolts completely and remove pressure
plate, disc and alignment tool.
INSTALLATION
(1) Check runout and free operation of new clutch
disc.
(2) Lubricate crankshaft pilot bearing with a NLGI
- 2 rated grease.
(3) Install clutch alignment tool in clutch disc hub
with the raised side of hub is facing away from the
flywheel.
NOTE: Flywheel side is imprinted on the disc face.
(4) Install alignment tool in pilot bearing and posi-
tion disc on the flywheel.
(5) Position pressure plate over disc and onto the
flywheel (Fig. 2).
(6) Align and hold pressure plate in position and
install bolts finger tight.
(7) Tighten bolts evenly and a few threads at a
time in a diagonal pattern.
CAUTION: Bolts must be tightened evenly and to
specified torque to avoid warping pressure plate
cover.
DRCLUTCH 6 - 5
CLUTCH (Continued)

(8) Tighten pressure plate bolts to:
²V6 & V8 Engines - 50 N´m (37 ft. lbs.)
²V10 & Diesel Engines - 30 N´m (22.5 ft. lbs.)
(9) Remove release lever and release bearing from
clutch housing. Apply Mopar high temperature bear-
ing grease to bore of release bearing, release lever
contact surfaces and release lever pivot stud (Fig. 3).
(10) Apply light coat of Mopar high temperature
bearing grease to splines of transmission input shaft
and to release bearing slide surface of the transmis-
sion front bearing retainer (Fig. 4).CAUTION: Do not over lubricate shaft splines. This
can result in grease contamination of the disc.
Fig. 1 PRESSURE PLATE POSITION-TYPICAL
1 - FLYWHEEL
2 - ALIGNMENT MARKS
3 - PRESSURE PLATE
Fig. 2 CLUTCH DISC AND PRESSURE PLATE
1 - FLYWHEEL
2 - PRESSURE PLATE AND DISC
3 - ALIGNMENT TOOL
Fig. 3 LUBRICATION POINTS
1 - CLUTCH HOUSING
2 - FORK PIVOT BALL
3 - RELEASE FORK
4 - RELEASE BEARING BORE
5 - LUBE POINTS
Fig. 4 INPUT SHAFT LUBRICATION POINTS
1 - INPUT SHAFT
2 - BEARING RETAINER
3 - SPLINE AND RELEASE BEARING SURFACE
6 - 6 CLUTCHDR
CLUTCH DISC (Continued)

(11) Wipe pilot bearing surface clean.
(12) Install release lever and bearing in clutch
housing. Verify spring clips that retain fork on pivot
ball and release bearing on fork are installed prop-
erly (Fig. 5).
NOTE: If release lever is installed correctly, the
lever part number will be toward the bottom of the
transmission and right side up. There is also a
stamped ªIº in the lever which goes to the pivot ball
side of the transmission.
(13) Install transmission and transfer case if
equipped.
(14) Check fluid level in clutch master cylinder.
CLUTCH HOUSING
DIAGNOSIS AND TESTING
The clutch housing maintains alignment between
the crankshaft and transmission input shaft. Mis-
alignment can cause clutch noise, hard shifting,
incomplete release and chatter. Also premature pilot
bearing, cover release fingers and clutch disc wear.
In severe cases, it can cause premature wear of the
transmission input shaft and front bearing.
NOTE: Only the NV4500 clutch housing can be
checked using the following bore and face runout
procedures. The NV5600 clutch housing is a inte-
gral part of the transmission and can only be
checked off the vehicle.
CLUTCH HOUSING BORE RUNOUT
CAUTION: On diesel engines if housing bore runout
exceeds 0.015 inch, the clutch housing/transmis-
sion adapter plate must be replaced. On gas
engines if housing bore runout exceeds 0.053 in.
the clutch housing must be replaced.
NOTE: Offset dowels are available for gas engines
to correct housing bore runout. They are not avail-
able for diesel engines.
(1) Remove the clutch housing.
(2) Remove the clutch cover and disc.
(3) Replace one of the flywheel bolts with an
appropriate size threaded rod that is 10 in. (25.4 cm)
long (Fig. 6). The rod will be used to mount the dial
indicator.
(4) Remove release fork from the clutch housing.
(5) Install clutch housing. Tighten the housing
bolts nearest the alignment dowels first.
(6) Mount dial indicator on the threaded rod and
position indicator plunger on the clutch housing bore
(Fig. 7).
(7) Rotate crankshaft until indicator plunger is at
the topof the housing bore. Zero the indicator at this
point.
(8) Rotate crankshaft and record indicator read-
ings at eight points (45É apart) around the bore (Fig.
8). Take measurement at least twice for accuracy.
(9) Subtract each reading from the one 180É oppo-
site to determine runout and direction. Bore runout
example (Fig. 8):
²0.000 ± (±0.007) = 0.007 in.
²+0.002 ± (±0.010) = 0.012 in.
²+0.004 ± (±0.005) = 0.009 in.
²±0.001 ± (+0.001) = ±0.002 in.
Fig. 5 FORK, BEARING AND SPRING CLIPS
1 - FORK
2 - SPRING CLIP
3 - BEARING
4 - SPRING CLIP
Fig. 6 DIAL INDICATOR MOUNTING STUD
1 - 7/16 - 20 THREAD
2 - NUT
3 - STUD OR THREADED ROD
4 - 10 INCHES LONG
DRCLUTCH 6 - 7
CLUTCH DISC (Continued)

(3) Disconnect release bearing from release fork
and remove bearing (Fig. 15).
INSTALLATION
(1) Inspect bearing slide surface on transmission
front bearing retainer. Replace retainer if slide sur-
face is scored, worn, or cracked.
(2) Inspect release lever and pivot stud. Be sure
stud is secure and in good condition. Be sure fork is
not distorted or worn. Replace fork spring clips if
bent or damaged.
(3) Lubricate input shaft splines, bearing retainer
slide surface, lever pivot ball stud, and release lever
pivot surface with Moparthigh temperature bearing
grease.
(4) Install release fork and release bearing (Fig.
16). Be sure fork and bearing are properly secured by
spring clips. Also be sure that the release fork is
installed properly. The rear side of the release lever
has one end with a raised area. This raised area goes
toward the slave cylinder side of the transmission.
(5) Install clutch housing, if removed.
(6) Install transmission and transfer case.(7) Check clutch master cylinder fluid level.
FLYWHEEL
DIAGNOSIS AND TESTING
Check flywheel runout whenever misalignment is
suspected. Flywheel runout should not exceed 0.08
mm (0.003 in.). Measure runout at the outer edge of
the flywheel face with a dial indicator. Mount the
indicator on a stud installed in place of one of the fly-
wheel bolts.
Fig. 14 CLUTCH HOUSING - NV4500
1 - ENGINE BLOCK
2 - CLUTCH DISC/PRESSURE PLATE
3 - CLUTCH HOUSING
4 - DUST COVER
Fig. 15 CLUTCH RELEASE COMPONENTS
1 - CONED WASHER
2 - CLUTCH HOUSING
3 - RELEASE FORK
4 - RELEASE BEARING AND SLEEVE
5 - PIVOT 23 N´m (200 IN. LBS.)
6 - SPRING CLIP
Fig. 16 Clutch Release Fork And
1 - PIVOT BALL
2 - FORK
3 - SLAVE CYLINDER OPENING
4 - BEARING
6 - 10 CLUTCHDR
CLUTCH RELEASE BEARING (Continued)

Common causes of runout are:
²heat warpage
²improper machining
²incorrect bolt tightening
²improper seating on crankshaft flange shoulder
²foreign material on crankshaft flange
Flywheel machining is not recommended. The fly-
wheel clutch surface is machined to a unique contour
and machining will negate this feature. Minor fly-
wheel scoring can be cleaned up by hand with 180
grit emery or with surface grinding equipment.
Remove only enough material to reduce scoring
(approximately 0.001 - 0.003 in.). Heavy stock
removal isnot recommended.Replace the flywheel
if scoring is severe and deeper than 0.076 mm (0.003
in.). Excessive stock removal can result in flywheel
cracking or warpage after installation; it can also
weaken the flywheel and interfere with proper clutch
release.
Clean the crankshaft flange before mounting the
flywheel. Dirt and grease on the flange surface may
cock the flywheel causing excessive runout. Use new
bolts when remounting a flywheel and secure the
bolts with Mopar Lock And Seal or equivalent.
Tighten flywheel bolts to specified torque only. Over-
tightening can distort the flywheel hub causing
runout.
REMOVAL
(1) Remove transmission.
(2) Remove pressure plate and clutch.
(3) Remove flywheel bolts and remove flywheel.
DISASSEMBLY
NOTE: If the teeth are worn or damaged, the fly-
wheel should be replaced as an assembly. This is
the recommended repair. In cases where a new fly-
wheel is not readily available, (V10/Diesel Engine
only) a replacement ring gear can be installed. The
following procedure must be observed to avoid
damaging the flywheel and replacement gear.
WARNING: WEAR PROTECTIVE GOGGLES OR
SAFETY GLASSES WHILE CUTTING RING GEAR.
(1) Mark position of the old gear for alignment ref-
erence on the flywheel. Use a scriber for this pur-
pose.
(2) Remove the old gear by cutting most of the way
through it (at one point) with an abrasive cut-off
wheel. Then complete removal with a cold chisel or
punch.
ASSEMBLY
NOTE: The ring gear is a shrink fit on the flywheel.
This means the gear must be expanded by heating
in order to install it. The method of heating and
expanding the gear is extremely important. Every
surface of the gear must be heated at the same
time to produce uniform expansion. An oven or
similar enclosed heating device must be used. Tem-
perature required for uniform expansion is approxi-
mately 375É F.
CAUTION: Do not use an oxy/acetylene torch to
remove the old gear, or to heat and expand a new
gear. The high temperature of the torch flame can
cause localized heating that will damage the fly-
wheel. In addition, using the torch to heat a replace-
ment gear will cause uneven heating and
expansion. The torch flame can also anneal the
gear teeth resulting in rapid wear and damage after
installation.
WARNING: WEAR PROTECTIVE GOGGLES OR
SAFETY GLASSES AND HEAT RESISTENT GLOVES
WHEN HANDLING A HEATED RING GEAR.
(1) The heated gear must be installed evenly to
avoid misalignment or distortion.
(2)
Position and install the heated ring gear on the
flywheel with a shop press and a suitable press plates.
(3) Place flywheel on work bench and let it cool in
normal shop air. Allow the ring gear to cool down
completely before installation it on the engine.
CAUTION: Do not use water or compressed air to
cool the flywheel. The rapid cooling produced by
water or compressed air will distort or crack the
new gear.
INSTALLATION
(1) Install flywheel on the crank shaft.
(2) Install flywheel bolts and tighten to 95 N´m
(70 ft. lbs.).
(3) Install clutch.
(4) Install transmission.
PILOT BEARING
REMOVAL
(1) Remove transmission.
(2) Remove clutch disc.
(3) Use a suitable blind hole puller to remove pilot
bearing.
DRCLUTCH 6 - 11
FLYWHEEL (Continued)

CAUTION: If the viscous fan drive is replaced
because of mechanical damage, the cooling fan
blades should also be inspected. Inspect for fatigue
cracks, loose blades, or loose rivets that could
have resulted from excessive vibration. Replace fan
blade assembly if any of these conditions are
found. Also inspect water pump bearing and shaft
assembly for any related damage due to a viscous
fan drive malfunction.
FAN DRIVE VISCOUS CLUTCH
- 5.9L DIESEL
DESCRIPTION
The electronically controlled viscous fan drive (Fig.
34) and (Fig. 33)is attached to the fan drive pulley
mounted to the engine. The coupling allows the fan
to be driven in a normal manner. The fan speed is
controlled by the electronic control module.
OPERATION
The Engine Control Module (ECM) controls the
level of engagement of the electronically controlled
viscous fan clutch by monitoring coolant tempera-
ture, intake manifold temperature, and air condition-
ing status. Based on cooling requirements, the ECMsends a signal to the viscous fan clutch to increase or
decrease the fan speed.
Fan speed is monitored by the ECM. Fan speeds
above or below a calibrated threshold will set a DTC.
Circuit concerns will also set fan clutch DTC's.
DIAGNOSIS AND TESTING - ELECTRONICALLY
CONTROLLED VISCOUS FAN DRIVE
NOISE
NOTE: It is normal for fan noise to be louder (roar-
ing) when:
²Fan duty cycle high. This may occur when ambi-
ent (outside air temperature) is very high.
²Engine loads and temperatures are high such as
when towing a trailer.
²Aggressive engine braking down a steep grade
where transmission temperatures may be high
²Cool silicone fluid within the fan drive unit is
being redistributed back to its normal disengaged
(warm) position. This can occur during the first 15
seconds to one minute after engine start-up on a cold
engine.
Fig. 33 Electronically Controlled Viscous Drive
1 - ELECTRONICALLY CONTROLLED VISCOUS FAN DRIVE
2 - MOUNTING NUT
3 - WIRING SUPPORT BRACKET
4 - ELECTRICAL CONNECTOR
Fig. 34 Fan Blade/Viscous Fan Drive - 5.9L Diesel
Engine
1 - ELECTRICAL CONNECTOR
2 - VISCOUS FAN DRIVE
3 - FAN BLADE
4 - BOLT (6)
5 - RADIATOR FAN PULLEY
7 - 52 ENGINEDR
FAN DRIVE VISCOUS CLUTCH-GAS ENGINES (Continued)

WIDE OPEN THROTTLE MODE
This is an Open Loop mode. During wide open
throttle operation, the PCM receives the following
inputs.
²Battery voltage
²Crankshaft position sensor
²Engine coolant temperature sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal
During wide open throttle conditions, the following
occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
the injection sequence and injector pulse width by
turning the ground circuit to each individual injector
on and off. The PCM ignores the oxygen sensor input
signal and provides a predetermined amount of addi-
tional fuel. This is done by adjusting injector pulse
width.
²The PCM adjusts ignition timing by turning the
ground path to the coil(s) on and off.
IGNITION SWITCH OFF MODE
When ignition switch is turned to OFF position,
the PCM stops operating the injectors, ignition coil,
ASD relay and fuel pump relay.
DESCRIPTION - 5 VOLT SUPPLIES
Two different Powertrain Control Module (PCM)
five volt supply circuits are used; primary and sec-
ondary.
DESCRIPTION - IGNITION CIRCUIT SENSE
This circuit ties the ignition switch to the Power-
train Control Module (PCM).
DESCRIPTION - POWER GROUNDS
The Powertrain Control Module (PCM) has 2 main
grounds. Both of these grounds are referred to as
power grounds. All of the high-current, noisy, electri-
cal devices are connected to these grounds as well as
all of the sensor returns. The sensor return comes
into the sensor return circuit, passes through noise
suppression, and is then connected to the power
ground.
The power ground is used to control ground cir-
cuits for the following PCM loads:
²Generator field winding
²Fuel injectors
²Ignition coil(s)
²Certain relays/solenoids
²Certain sensors
DESCRIPTION - SENSOR RETURN
The Sensor Return circuits are internal to the Pow-
ertrain Control Module (PCM).
Sensor Return provides a low±noise ground refer-
ence for all engine control system sensors. Refer to
Power Grounds for more information.
OPERATION
OPERATION - PCM
The PCM operates the fuel system. The PCM is a
pre-programmed, triple microprocessor digital com-
puter. It regulates ignition timing, air-fuel ratio,
emission control devices, charging system, certain
transmission features, speed control, air conditioning
compressor clutch engagement and idle speed. The
PCM can adapt its programming to meet changing
operating conditions.
The PCM receives input signals from various
switches and sensors. Based on these inputs, the
PCM regulates various engine and vehicle operations
through different system components. These compo-
nents are referred to as Powertrain Control Module
(PCM) Outputs. The sensors and switches that pro-
vide inputs to the PCM are considered Powertrain
Control Module (PCM) Inputs.
The PCM adjusts ignition timing based upon
inputs it receives from sensors that react to: engine
rpm, manifold absolute pressure, engine coolant tem-
perature, throttle position, transmission gear selec-
tion (automatic transmission), vehicle speed, power
steering pump pressure, and the brake switch.
The PCM adjusts idle speed based on inputs it
receives from sensors that react to: throttle position,
vehicle speed, transmission gear selection, engine
coolant temperature and from inputs it receives from
the air conditioning clutch switch and brake switch.
Based on inputs that it receives, the PCM adjusts
ignition coil dwell. The PCM also adjusts the gener-
ator charge rate through control of the generator
field and provides speed control operation.
NOTE: PCM Inputs:
²ABS module (if equipped)
²A/C request (if equipped with factory A/C)
²A/C select (if equipped with factory A/C)
²A/C pressure transducer
²Auto shutdown (ASD) sense
²Battery temperature sensor
²Battery voltage
²Brake switch
²J1850 bus (+) circuits
²J1850 bus (-) circuits
²Camshaft position sensor signal
²Crankshaft position sensor
8E - 10 ELECTRONIC CONTROL MODULESDR
POWERTRAIN CONTROL MODULE (Continued)