Chrysler Vehicle User Manual page 265

6 - 8 CLUTCH
FLYWHEEL (Continued)
OPERATION
The flywheel serves to dampen the engine firing
pulses. The heavy weight of the flywheel relative to
the rotating mass of the engine components serves to
stabilize the flow of power to the remainder of the
drivetrain. The crankshaft has the tendency to
attempt to speed up and slow down in response to
the cylinder firing pulses. The flywheel dampens
these impulses by absorbing energy when the crank-
shaft speeds and releasing the energy back into the
system when the crankshaft slows down.
On a Dual Mass Flywheel the additional secondary
mass coupled to the transmission lowers the natural
frequency of the transmission rotating elements. This
decreases the transmission gear rattle. The damper
springs between the two flywheel masses replace the
clutch disc damper springs and assist in a smooth
transfer of torque to the transmission.
CAUTION: The Dual Mass Flywheel is serviced as
an assembly only and should never be taken apart.
DIAGNOSIS AND TESTING - FLYWHEEL
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.
Common causes of runout are:
• heat warpage
• improper machining
• incorrect bolt tightening
• improper seating on crankshaft flange shoulder
• foreign 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 is not 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.
PILOT BEARING
REMOVAL
(1) Remove the transmission.
(2) Remove pressure plate and clutch disc.
(3) Remove pilot bearing with an internal (blind
hole) puller.
INSTALLATION
(1) Lubricate new bearing with Mopar high tem-
perature bearing grease or equivalent.
(2) Start new bearing into crankshaft by hand.
Then seat bearing with clutch alignment tool (Fig. 6).
Fig. 6 Pilot Bearing Installer
1 - PILOT BEARING
2 - ALIGNMENT TOOL
(3) Lightly scuff sand flywheel surface with 180
grit emery cloth. Then clean surface with wax and
grease remover.
(4) Install clutch disc and pressure plate.
(5) Install the transmission.
TJ