1998 DODGE RAM 1500 Removal

PRESSURE INCREASE
The inlet valve is open and the outlet valve is
closed during the pressure increase cycle. The pres-
sure increase cycle is used to reapply thew brakes.
This cycle controls re-application of fluid apply pres-
sure.
REMOVAL
(1) Install a prop rod on the brake pedal to keep
pressure on the brake system.
(2) Disconnect the battery cables from the battery.
(3) Remove the battery.
(4) Disconnect the two electrical harness connec-
tors (Fig. 5).
(5) Remove the five brake lines from the HCU
(Fig. 5).
(6) Remove HCU/CAB mounting bolts and remove
the HCU/CAB (Fig. 5).
INSTALLATION
NOTE: If the CAB is being replaced with a new CAB
is must be reprogrammed with the use of a DRB III.
(1) Install HCU/CAB on the mounts and Tighten
the bolts to 15N´m (11 ft. lbs.) (Fig. 5).
(2) Install the five brake lines to the HCU and
tighten to 19 N´m (170 in. lbs.) (Fig. 5).
(3) Install the two electrical harness connectors to
the HCU/CAB and push down on the release to
secure the connectors.
(4) Install the battery.
(5) Install the battery cables to the battery.
(6) Remove the prop rod on the brake pedal.
(7) Bleed ABS brake system (Refer to 5 - BRAKES
- STANDARD PROCEDURE).
RWAL VALVE
DESCRIPTION
Rear Wheel Antilock (RWAL) brake system is stan-
dard equipment on 1500 series vehicles. The RWAL
brake system is designed to prevent rear wheel
lock-up on virtually all types of road surfaces. RWAL
braking is desirable because a vehicle which is
stopped without locking the rear wheels will retain
directional stability. This allows the driver to retain
greater control of the vehicle during braking.
The valve is located on the drivers side inner
fender under the hood. The valve modulates hydrau-
lic pressure to the rear brakes.
The RWAL components include:
²RWAL Valve
²Controller Antilock brake (CAB)
²Rear Wheel Speed Sensor (WSS)
OPERATION
When the brakes are applied, hydraulic fluid is
routed from the master cylinder's secondary circuit to
the RWAL valve. From there hydraulic fluid is routed
to the rear brakes. The Controller Antilock Brake
(CAB) contains an Electronic Variable Brake Propor-
tioning (EVBP) control algorithm, which proportions
the applied braking force to the rear wheels during
braking. The EVBP function of the RWAL system
takes the place of a conventional hydraulic propor-
tioning valve. The CAB monitors the rear wheel
speed through the rear wheel speed sensor and cal-
culates an estimated vehicle deceleration. When an
established deceleration threshold is exceeded, an
isolation valve is closed to hold the applied brake
pressure to the rear brakes constant. Upon further
increases in the estimated vehicle deceleration, the
isolation valve is selectively opened to increase rear
brake pressure in proportion to the front brake pres-
sure. If impending rear wheel lock-up is sensed, the
CAB signals the RWAL valve to modulate hydraulic
brake pressure to the rear wheels to prevent lock-up.
NORMAL BRAKING Since the RWAL valve also
performs the EVBP or proportioning function, vehicle
deceleration under normal braking may be sufficient
to trigger the EVBP function of the RWAL system
without full RWAL activity as would normally occur
during an impending rear wheel lock-up. As previ-
ously mentioned, the isolation valve is selectively
closed and opened to increase rear brake pressure in
proportion to the front brake pressure under EVBP
control. Slight brake pedal pulsations may be noticed
as the isolation valve is opened.
Fig. 5 HYDRAULIC CONTROL UNIT
1 - HYDRAULIC CONTROL UNIT
2 - MOUNTING BOLTS
5 - 50 BRAKES - ABSDR
HCU (HYDRAULIC CONTROL UNIT) (Continued)

REMOVAL
(1) Install a prop rod on the brake pedal to keep
pressure on the brake system.
(2) Disconnect the battery cables from the battery.
(3) Remove the battery.
(4) Disconnect the electrical harness connector
(Fig. 6).
(5) Remove the brake lines from the rwal valve
(Fig. 6).
(6) Remove rwal valve mounting nuts and remove
the rwal valve (Fig. 6).
INSTALLATION
(1) Install rwal valve and Tighten the nuts to 15
N´m (11 ft. lbs.) (Fig. 6).
(2) Install the brake lines to the rwal valve and
tighten to 19 N´m (170 in. lbs.) (Fig. 6).
(3) Install the electrical harness connector to the
rwal valve and secure the connector.
(4) Install the battery.
(5) Install the battery cables to the battery.
(6) Remove the prop rod on the brake pedal.
(7) Bleed ABS brake system (Refer to 5 - BRAKES
- STANDARD PROCEDURE).
Fig. 6 RWAL VALVE
1 - RWAL VALVE
2 - MOUNTING NUTS
DRBRAKES - ABS 5 - 51
RWAL VALVE (Continued)

CLUTCH
TABLE OF CONTENTS
page page
CLUTCH
WARNING.............................1
DIAGNOSIS AND TESTING................1
SPECIFICATIONS........................5
CLUTCH DISC
REMOVAL.............................5
INSTALLATION..........................5
CLUTCH HOUSING
DIAGNOSIS AND TESTING................7
REMOVAL.............................9
INSTALLATION..........................9
CLUTCH RELEASE BEARING
REMOVAL.............................9
INSTALLATION.........................10
FLYWHEEL
DIAGNOSIS AND TESTING................10REMOVAL.............................11
DISASSEMBLY.........................11
ASSEMBLY............................11
INSTALLATION.........................11
PILOT BEARING
REMOVAL.............................11
INSTALLATION.........................12
LINKAGE
REMOVAL.............................12
INSTALLATION.........................12
CLUTCH PEDAL POSITION SWITCH
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING................13
CLUTCH
WARNING
WARNING: Exercise care when servicing clutch
components. Factory installed clutch discs do not
contain asbestos fibers. Dust and dirt on clutch
parts may contain asbestos fibers from aftermarket
components. Breathing excessive concentrations of
these fibers can cause serious bodily harm. Wear a
respirator during service and never clean clutch
components with compressed air or with a dry
brush. Either clean the components with water
dampened rags or use a vacuum cleaner specifi-
cally designed to remove asbestos fibers and dust.
Do not create dust by sanding a clutch discs.
Replace the disc if the friction material is damaged.
Dispose of all dust and dirt containing asbestos
fibers in sealed bags or containers. This will mini-
mize exposure to yourself and to others. Follow all
recommended safety practices prescribed by the
occupational safety and health administration
(OSHA) and the environmental safety agency (EPA),
for the handling and disposal of products contain-
ing asbestos. Failure to follow these instructions
may result in personal injury or death
DIAGNOSIS AND TESTING
Road test and inspect components to determine a
clutch problem. Road test the vehicle at normalspeeds. Shift the transmission through all gear
ranges and observe clutch action. If clutch chatters,
grabs, slips or does not release properly, remove and
inspect clutch components. If problem is noise or
hard shifting, further diagnosis may be needed to the
transmission and driveline component.
CLUTCH CONTAMINATION
Contamination is a frequent cause of clutch mal-
functions. Oil, water or clutch fluid on the clutch disc
and pressure plate surfaces will cause chatter, slip
and grab. Oil contamination indicates a leak at
either the rear main seal or transmission input shaft.
Clutch fluid leaks are usually from damaged slave
cylinder push rod seals. Heat buildup caused by slip-
page between the pressure plate, disc and flywheel
can bake the oil residue onto the components. The
glaze-like residue ranges in color from amber to
black.
Road splash contamination is dirt/water entering
the clutch housing due to loose bolts, housing cracks.
Driving through deep water puddles can force water/
road splash into the housing through such openings.
IMPROPER RELEASE OR CLUTCH ENGAGEMENT
Clutch release or engagement problems can be
caused by worn or damage clutch components.
Release problems can cause hard shifting and
noise. Look for leaks at clutch cylinders, connecting
line and loose slave cylinder bolts. Also worn/loose
release fork, pivot stud, clutch disc, pressure plate or
release bearing.
DRCLUTCH 6 - 1

Engagement problems can cause slip, chatter/shud-
der and noisy operation. The causes may be clutch
disc contamination, wear, distortion or flywheel dam-
age.
CLUTCH MISALIGNMENT
Clutch components must be in proper alignment
with the crankshaft and transmission input shaft.
Misalignment caused by excessive runout or warpage
of any clutch component will cause grab, chatter and
improper clutch release.
CLUTCH COVER AND DISC RUNOUT
Check the clutch disc before installation. Axial
(face) runout of anewdisc should not exceed 0.50
mm (0.020 in.). Measure runout about 6 mm (1/4 in.)
from the outer edge of the disc facing. Obtain
another disc if runout is excessive.
Check condition of the clutch before installation. A
warped cover or diaphragm spring will cause grab
and incomplete release or engagement. Be careful
when handling the cover and disc. Impact can distort
the cover, diaphragm spring, release fingers and the
hub of the clutch disc.
Use an alignment tool when positioning the disc on
the flywheel. The tool prevents accidental misalign-
ment which could result in cover distortion and disc
damage.
A frequent cause of clutch cover distortion (and
consequent misalignment) is improper bolt tighten-
ing.
FLYWHEEL RUNOUT
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.
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 turning equipment. Remove only
enough material to reduce scoring (approximately
0.001 - 0.003 in.). Heavy stock removal isnot rec-
ommended.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 fly-
wheel 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.
DIAGNOSIS CHART
The diagnosis charts Diagnosis Chart describe
common clutch problems, causes and correction.
DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
Disc facing worn out 1. Normal wear. 1. Replace cover and disc.
2. Driver frequently rides (slips) the
clutch. Results in rapid overheating
and wear.2. Replace cover and disc.
3. Insufficient clutch cover
diaphragm spring tension.3. Replace cover and disc.
6 - 2 CLUTCHDR
CLUTCH (Continued)

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)

To correct this example (Fig. 11) the shims needed
between the clutch housing and transmission are:
²0.009 in. at the 0.000 corner
²0.012 in. at the ±0.003 corner
²0.013 in. at the ±0.004 corner
After installing the clutch assembly and housing,
tighten the housing bolts nearest the alignment dow-
els first.
NOTE: Shims can be made from shim stock or sim-
ilar materials of the required thickness (Fig. 12).
REMOVAL
(1) Remove transmission and transfer case (Fig.
13).
(2) Remove starter from clutch housing.
(3) Remove structural dust cover bolts from clutch
housing.
CAUTION: Do not remove structural dust cover
from enigne block. If cover is removed clutch hous-
ing and cover must be aligned with the engine.(4) Remove clutch housing bolts and remove hous-
ing from the engine.
INSTALLATION
(1) Clean housing mounting surface of engine
block with wax and grease remover.
(2) Verify that clutch housing alignment dowels
are in good condition and properly seated.
(3) Transfer slave cylinder, release fork and boot,
fork pivot stud and wire/hose brackets to new hous-
ing.
(4) Install structural dust cover if removed (Refer
to 9 - ENGINE/ENGINE BLOCK/STRUCTURAL
COVER - INSTALLATION).
(5) Align and install clutch housing on engine (Fig.
14). Tighten housing bolts across the top of the hous-
ing first and to the following torque values:
²ªAº bolts 1/4in. diameter - 4.5 N´m (40 in.lb.)
²ªAº bolts 3/8in. diameter - 40 N´m (30 ft.lb.)
²ªAº bolts 7/16in. diameter - 68 N´m (50 ft.lb.)
²ªBº bolts for 5.7L 5.9L TD/8.0L engines - 47.5
N´m (40 ft.lb.)
²ªCº bolts for 5.7L engine - 68 N´m (50 ft.lb.)
²ªCº bolts for 5.9L TD engine - 47.5 N´m (35
ft.lb.)
²ªCº bolts for 8.0L engine - 74.5 N´m (55 ft.lb.)
(6) Install starter to clutch housing.
(7) Install transmission and transfer case, if
equipped.
CLUTCH RELEASE BEARING
REMOVAL
(1) Remove transmission and transfer case, if
equipped.
(2) Remove spring clip.
Fig. 11 MEASUREMENT POINTS AND READINGS
1 - CLUTCH HOUSING FACE CIRCLE (AT RIM OF BORE)
Fig. 12 ALIGNMENT SHIMS
1 - CUT/DRILL BOLT HOLE TO SIZE
2 - SHIM STOCK
3 - MAKE SHIM 1-INCH DIAMETER
Fig. 13 TRANSMISSION/CLUTCH HOUSING-NV4500
1 - CLUTCH HOUSING
2 - TRANSMISSION
DRCLUTCH 6 - 9
CLUTCH HOUSING (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)