clutch CHRYSLER CARAVAN 2002 Owner's Manual
Page 123 of 2399
VISCOUS COUPLER
DESCRIPTION
The heart of the all-wheel drive system is the
inter-axle viscous coupling and bi-directional over-
running clutch. Under normal driving the vehicle
retains predominantly front wheel drive characteris-
tics. The all-wheel drive takes effect when the front
wheels start to slip. Under normal level road,
straight line driving, 100% of the torque is allocated
to the front wheels. The viscous coupler allows more
torque to the rear wheels in accordance with the
amount of slippage at the front wheels. The variable
torque distribution is automatic with no driver
inputs required.
OPERATION
The viscous coupler (Fig. 46) is a housing nearly
filled with a high viscosity silicone liquid and thin
metal plates alternately splined to an inner and
outer drum. The viscous coupler provides torque in
the following modes:
²Shear mode (normal operation)
²Hump mode (locked mode)The inner plates are slotted around the radius and
the outer plates have holes in them. In the shear
mode (normal operation), the plates are evenly
spaced and the torque is created by the shearing of
the plates through the fluid and 90-100% of the
torque is applied to the rear axle. During the shear
mode, a fluid flow pattern is created from this design
(holes and slots). This fluid flow causes high pressure
on each side of each pair of plates and low pressure
between each pair of plates.
When a high speed difference (shear) occurs
because of loss of traction (one axle spinning faster
than the other), the silicone fluid expands as it heats
from this shearing. When the silicone expands to fill
the viscous coupler completely, this pressure differ-
ence is high enough to squeeze each pair of plates
together. The resulting hump torque is up to 8 times
higher than the shear torque. When the viscous cou-
pler is in the hump mode, it does not lock the axles
(undifferentiated 4-Wheel Drive). It controls the
amount of slippage while delivering maximum power
to the axle having greatest traction. Once the speed
difference equalizes the fluid and plates cool down
and the viscous coupler goes back to the shear mode.
3 - 44 REAR DRIVELINE MODULERS
ProCarManuals.com
Page 124 of 2399
Fig. 46 Bi-directional Overrunning Clutch (BOC) and Viscous Coupler Powerflow
1 - POWERFLOW - BOC OVERUNNING 6 - VISCOUS COUPLER
2 - POWERFLOW - BOC LOCKED 7 - BOC ROLLER CAGE
3 - BOC GROUND TAB 8 - BOC INPUT SHAFT
4 - FRICTION BRAKE SHOES 9 - INPUT FLANGE
5 - BOC ROLLERS
RSREAR DRIVELINE MODULE3-45
VISCOUS COUPLER (Continued)
ProCarManuals.com
Page 126 of 2399
(5) Using suitable screwdriver, remove input
flange seal from overrunning clutch housing (Fig.
50).
INSTALLATION
(1) Using tool 8802, install input flange seal to
overrunning clutch case (Fig. 51).(2) Install input flange (Fig. 52).
(3) Install flange nut and washer. Using tool 6958,
torque flange nut to 135 N´m (100 ft. lbs.) (Fig. 53).
(4) Install propeller shaft. (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/PROPELLER SHAFT -
INSTALLATION)
(5) Lower vehicle.
Fig. 50 Input Flange Seal Removal
1 - INPUT FLANGE SEAL
2 - SCREWDRIVER
Fig. 51 Input Flange Seal Installation
1 - TOOL 8802
2 - HAMMER
Fig. 52 Input Flange
1 - INPUT FLANGE/SHIELD
Fig. 53 Input Flange Nut
1 - INPUT FLANGE
2 - TOOL 6958
RSREAR DRIVELINE MODULE3-47
INPUT FLANGE SEAL (Continued)
ProCarManuals.com
Page 236 of 2399
CLUTCH
TABLE OF CONTENTS
page page
CLUTCH
DESCRIPTION..........................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CLUTCH
SYSTEM.............................3
DIAGNOSIS AND TESTING - DRIVE PLATE
MISALIGNMENT.......................5
DIAGNOSIS AND TESTING - CLUTCH
COVER AND DISC RUNOUT..............6
DIAGNOSIS AND TESTING - CLUTCH
CHATTER COMPLAINTS.................6
SPECIAL TOOLS - T850 TRANSAXLE........6
CLUTCH RELEASE LEVER AND BEARING
REMOVAL.............................6
INSTALLATION..........................7
MASTER CYLINDER - RHD
REMOVAL.............................8INSTALLATION..........................8
MASTER CYLINDER - LHD
REMOVAL.............................9
INSTALLATION.........................10
MODULAR CLUTCH ASSY - 2.4L GAS
REMOVAL.............................11
INSTALLATION.........................11
SLAVE CYLINDER
REMOVAL.............................11
INSTALLATION.........................11
CLUTCH DISC AND PRESSURE PLATE - 2.5L
TD
REMOVAL.............................12
INSTALLATION.........................12
FLYWHEEL
REMOVAL.............................13
INSTALLATION.........................13
CLUTCH
DESCRIPTION
CLUTCH COMPONENTS
Models equipped with a 2.4L Gas engine utilize a
modular clutch assembly (Fig. 1). The modular clutch
consists of a single, dry-type clutch disc, a diaphragm
style clutch cover, and an integrated flywheel. The
clutch cover (pressure plate) is riveted to the fly-
wheel, and therefore can only be serviced as an
assembly.
Models equipped with the 2.5L Turbo Diesel engine
utilize a conventional clutch system (Fig. 2). This
system consists of a flywheel, clutch disc, and clutch
cover (pressure plate), which is fastened to the fly-
wheel, capturing the clutch disc within. Each compo-
nent is individually serviceable, however it ishighly
recommended that the clutch cover and disc be
replaced as a set.
Fig. 1 Modular Clutch AssemblyÐ2.4L Gas Engines
1 - MODULAR CLUTCH ASSEMBLY
RSCLUTCH6-1
ProCarManuals.com
Page 237 of 2399
RELEASE SYSTEM
All models utilize a hydraulic clutch release sys-
tem, conisting of a clutch master cylinder attached to
the clutch pedal (Fig. 3), and a slave cylinder fas-
tened to the transaxle which operates the clutch
release lever (Fig. 4). When the driver depresses the
clutch pedal, the master cylinder pushrod travels
through the cylinder bore, displacing fluid through
the master cylinder plumbing. This fluid displace-
ment forces the slave cylinder piston to travel, forc-
ing the clutch release bearing into the clutch
diaphragm spring via the release lever and leverage
(Fig. 5). This releases the clamping force on the
clutch disc, allowing the engine crankshaft to rotate
independently from the transaxle input shaft.
Fig. 2 Clutch Disc and Pressure PlateÐ2.5L TD Engines
1 - FLYWHEEL
2 - DISC3 - PRESSURE PLATE
Fig. 3 Clutch Master CylinderÐTypical
6 - 2 CLUTCHRS
CLUTCH (Continued)
ProCarManuals.com
Page 238 of 2399
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CLUTCH SYSTEM
Clutch problem diagnosis will generally require a
road test to determine the type of fault. Componentinspection will then determine the problem after road
testing.
Drive the vehicle at normal speeds during road
test. Shift the transaxle through all gear ranges and
observe clutch action. If chatter, grab, slip, or
improper release is experienced, remove and inspect
the clutch components. If the problem is noise or
hard shifting, further diagnosis may be needed. The
transaxle or other driveline components may actually
be at fault.
SERVICE DIAGNOSIS - CLUTCH GRAB/CHATTER
CONDITION POSSIBLE CAUSES CORRECTION
CLUTCH DISC FACING
COVERED WITH OIL OR
GREASEOil leak at engine rear main or
transaxle input shaft seal.Correct leak and replace modular clutch
assembly (2.4L Gas) or clutch cover and
disc (2.5L TD).
Too much grease applied to splines
of disc and input shaft.Apply lighter coating of grease to splines.
NO FAULT FOUND WITH
CLUTCH
COMPONENTSProblem actually related to
suspension or driveline component.Further diagnosis required. Check
engine/transmission mounts, suspension
attaching parts and other driveline
components as needed.
Engine related problems. Check EFI and ignition systems.
PARTIAL ENGAGEMENT
OF CLUTCH DISCClutch cover, spring, or release
fingers bent, distorted (rough
handling, improper assembly).Replace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
Fig. 4 Slave Cylinder Removal/Installation
1 - MOUNTING HOLE
2 - SLAVE CYLINDER
3 - ACCESS HOLE
4 - NYLON ANTI-ROTATION TAB
Fig. 5 Release Bearing and Lever
1 - RELEASE LEVER
2 - RELEASE BEARING
RSCLUTCH6-3
CLUTCH (Continued)
ProCarManuals.com
Page 239 of 2399
CONDITION POSSIBLE CAUSES CORRECTION
Clutch disc damaged or distorted. Replace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
Clutch misalignment. Verify modular clutch pilot plate alignment
to crankshaft. Replace the modular clutch
assembly (2.4L Gas) or clutch cover and
disc (2.5L TD) if the pilot plate is loose or
bent.
Improper transaxle-to-engine
installation.Verify transaxle is properly installed to
engine.
SERVICE DIAGNOSIS - CLUTCH SLIPS
CONDITION POSSIBLE CAUSES CORRECTION
DISC FACING WORN OUT Normal wear. Replace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
Driver frequently rides (slips) clutch,
results in rapid wear, overheating.Replace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
Insufficient clutch cover diaphragm
spring tensionReplace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
CLUTCH DISC FACING
CONTAMINATED WITH
OIL OR GREASELeak at rear main oil seal or
transaxle input shaft sealReplace leaking seals. Replace modular
clutch assembly (2.4L Gas) or clutch cover
and disc (2.5L TD).
Excessive amount of grease applied
to input shaft splinesApply less grease to input shaft. Replace
modular clutch assembly (2.4L Gas) or
clutch cover and disc (2.5L TD).
Road splash, water entering housing Seal housing. Inspect clutch assembly.
CLUTCH IS RUNNING
PARTIALLY DISENGAGEDRelease bearing sticking or binding,
does not return to normal running
position.Verify that bearing is actually binding. Then,
replace bearing and transmission front
bearing retainer if sleeve surface is
damaged.
Clutch pedal not returning to static
position.Inspect pedal assembly for damage and/or
obstructions. Replace componnents as
necessary.
Clutch master cylinder or pushrod
damaged causing high preload.Replace clutch master cylinder assembly.
Slave cylinder binding or stuck. Replace slave cylinder.
CLUTCH DISC FACINGS
HAVE FRACTURED INTO
SMALL PIECESLeak at rear main or transaxle input
shaft sealReplace seal. Replace modular clutch
assembly (2.4L Gas) or clutch cover and
disc (2.5L TD)..
Excessive heat from slippage Replace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
6 - 4 CLUTCHRS
CLUTCH (Continued)
ProCarManuals.com
Page 240 of 2399
SERVICE DIAGNOSIS - IMPROPER CLUTCH RELEASE
CONDITION POSSIBLE CAUSES CORRECTION
CLUTCH DISC BINDS ON
INPUT SHAFT SPLINESClutch disc hub splines damaged
during installationClean, smooth, and lubricate disc and shaft
splines. Replace modular clutch assembly,
or clutch disc, and/or input shaft if splines
are severely damaged.
Input shaft splines rough, damaged. Clean input shaft splines. Then lube.
Corrosion or rust formations on
splines of input shaft and discClean input shaft splines and disc splines,
then lube
CLUTCH DISC RUSTED
TO FLYWHEEL AND/OR
PRESSURE PLATEOccurs in vehicles stored or not
driven for extended period of time.
Also occurs after steam cleaning if
vehicle is not used for extended
period.Replace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
CLUTCH WILL NOT
DISENGAGE PROPERLYDisc bent, distorted during transaxle
installationReplace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
Clutch cover diaphragm spring
damaged during transaxle installationReplace modular clutch assembly (2.4L
Gas) or clutch cover and disc (2.5L TD).
Release fork bent, loose, or
damagedReplace fork if worn or damaged
Air in clutch hydraulic circuit. Allow system to self-bleed or replace
hydraulic components.
Leak in clutch hydraulic circuit. Replace worn/damaged/leaking hydraulic
components.
Clutch pedal requires
excessive force (high
release load).Clutch disc is worn. Replace modular clutch assembly (2.4L
models) or clutch cover and disc (2.5L TD
models).
SERVICE DIAGNOSIS - CLUTCH PEDAL NOISE
CONDITION POSSIBLE CAUSES CORRECTION
CLUTCH PEDAL
SQUEAKS WHEN
DEPRESSED TO FLOORPedal bushings worn out or
inadequate lubricationReplace or lubricate bushings at clutch
pedal pivot or master cylinder pushrod.
Clutch pedal return spring worn out Lubricate or replace return spring
CLUTCH PEDAL
SQUEAKS DURING
OPERATIONClutch release lever pivot stud has
inadequate lubricationLubricate or replace clutch release lever
DIAGNOSIS AND TESTING - DRIVE PLATE
MISALIGNMENT
Common causes of misalignment are:
²Heat warping
²Mounting drive plate on a dirty crankshaft
flange
²Incorrect bolt tightening
²Improper seating on the crankshaft shoulder²Loose crankshaft bolts
Clean the crankshaft flange before mounting the
drive plate. Dirt and grease on the flange surface
may misalign the flywheel, causing excessive runout.
Use new bolts when mounting drive plate to crank-
shaft. Tighten drive plate bolts to specified torque
only. Over-tightening can distort the drive plate hub
causing excessive runout.
RSCLUTCH6-5
CLUTCH (Continued)
ProCarManuals.com
Page 241 of 2399
DIAGNOSIS AND TESTING - CLUTCH COVER
AND DISC RUNOUT
Check condition of the clutch cover before installa-
tion. A warped cover or diaphragm spring will cause
grab and/or incomplete release or engagement. Use
care when handling the clutch assembly. Impact can
distort the cover, diaphragm spring, and release fin-
gers.
DIAGNOSIS AND TESTING - CLUTCH CHATTER
COMPLAINTS
For all clutch chatter complaints, perform the fol-
lowing:
(1) Check for loose, misaligned, or broken engine
and transmission mounts. If present, they should be
corrected at this time. Test vehicle for chatter. If
chatter is gone, there is no need to go any further.
(2) If chatter persists, check hydraulic clutch
release system is functioning properly.
(3) Check for loose connections in drivetrain. Cor-
rect any problems and determine if clutch chatter
complaints have been satisfied. If not:
(a) Remove transaxle.
(b) Check to see if the release bearing is sticky
or binding. Replace bearing, if needed.
(c) Check linkage for excessive wear on the pivot
stud and fork fingers. Replace all worn parts.
(d) Check clutch assembly for contamination
(dirt, oil). Replace clutch assembly, if required.
(e) Check to see if the clutch disc hub splines
are damaged. Replace with new clutch assembly, if
necessary.
(f) Check input shaft splines for damage.
Replace, if necessary.
(g) Check for uneven wear on clutch fingers.
(h) Check for broken clutch cover diaphragm
spring fingers. Replace with new clutch assembly,
if necessary.
SPECIAL TOOLS - T850 TRANSAXLE
CLUTCH RELEASE LEVER AND
BEARING
REMOVAL
(1) Remove transaxle assembly. (Refer to 21 -
TRANSMISSION/TRANSAXLE/MANUAL -
REMOVAL)
(2) Remove modular clutch assembly from input
shaft (2.4L Gas models only).
(3) Grasp clutch release lever and bearing (Fig. 6)
with both hands and pull outward using moderate
pressure to release lever from pivot ball.
Disconnect Tool, 6638A
Remover/Installer, 6891
Fig. 6 Release Bearing and Lever
1 - RELEASE LEVER
2 - RELEASE BEARING
6 - 6 CLUTCHRS
CLUTCH (Continued)
ProCarManuals.com
Page 242 of 2399
(4) Separate release bearing from lever.
NOTE: Remove release lever pivot ball(s) ONLY if
replacement is necessary.
(5) Remove pivot ball(s) using slide hammer
C-3752 and remover/installer 6891 (Fig. 7).
INSTALLATION
(1) If removed, installnewrelease lever pivot
ball(s) using slide hammer C-3752 and remover/in-
staller 6891 (Fig. 8) (Fig. 9).
(2) Install clutch release bearing to lever. Apply
grease to interface points. Make sure release bearing
retainers engage lever pocket as shown in (Fig. 10).
(3) Apply grease to pivot ball, and on release lever
at slave cylinder contact point.
Fig. 7 Pivot Ball Removal/Installation
1 - C-3752 SLIDE HAMMER
2 - REMOVER/INSTALLER 6891
3 - PIVOT BALL
Fig. 8 Pivot Ball Removal/Installation
1 - C-3752 SLIDE HAMMER
2 - REMOVER/INSTALLER 6891
3 - PIVOT BALL
Fig. 9 Pivot Ball Position
1 - PIVOT BALL (1)
RSCLUTCH6-7
CLUTCH RELEASE LEVER AND BEARING (Continued)
ProCarManuals.com