1

NVR CLUTCH SYSTEM
Noise Vibration Reduction

Greatly improved performance and environmentally friendly
NVR vs. Conventional type - Component Comparison
Conventional type

Employs single-unit disc spring assembly
NVR performance is greatly
increased by positioning thecoil springs at the outermost
edge of the disc plate.

Rivet

Connector pin

Use of seat stopper
Conventional type
Torque angle is increased by theaddition of spring stoppers on
Normalthe torsion seat.
(Constant speed)

NVR

Twist
(Accelerating anddecelerating)

Torsion Angle

NVR Features
Improved ride comfort

Ability to apply torque with less force improves vibration and sound absorption, enabling a
quiet and stable ride.

Improved part
coverage

Greater product coverage and part number consolidation is achieved by increasing the torquerange.

Improved shift feel

Lower inertia moment by decreasing disc weight, reduces sticking and gear noise.

Improved durability

Addition of seat stoppers to the torsion spring reduces spring wear, increasing durability.

Improved pedal feel

Increased strength and easier half-clutching is achieved through improvements in cover
design.

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Diagnostic Manual

Clutch Disc Improvements throughout the NVR clutch disc and cover increases fuel economy, provides
a stable ride, and extends product life.
&
CoverPart number consolidations increase coverage with fewer parts.
NVR

Addition of spring retainer to torsion seat
New coil spring design
eliminates contact with themetal plate.

Interfering material(In motion)

Use of large capacity coil springs
Large capacity coil springs
enable expanded torque range.

User Benefits
Comparison against
conventional discs

Driving
Comfort

NV Performance(Ride Comfort)

Improved
Fuel
EconomyTorque Range(Increased Coverage)

Conventional type
NVR

Friction Life
(Durability)

Inertia Moment(Shift Feel)

Cover Strength(Pedal Feel)

11

Improved

Reliability
Customer

Improved

VehiclePerformance

Environmental
Friendliness

Improved

Improved2

AISIN Clutch Characteristics
Clutch Disc Characteristics[Extended Product Life][Improved Clutch Release Performance][Smoother Engagement][Reduced Vibration/Noise]

Improved product life by adopting facings with excellent heat and wear resistance.
Clutch drag prevented by using circumferential grooves in the facings and ensuring sufficient groove depth.
Improved spline sliding properties by using nickel coated splines.
Smoother clutch engagement by adopting facings with excellent anti-shudder properties.
Reduced drive system vibration and noise through the use of a rigid clutch disc structure andreduced deflection of immobile cushion rubbers.

<Clutch Disc Types>
Torsion Type
Hysteresis Structure
Clutch Hub Structure

Rubber Torsion
Standard Type
Integral Hub

Standard Type
Integral Hub

Coil torsion
Variable Hysteresis Type
Dual HubCharacteristics
1. Drive system for medium to hightorque ranges. Reduced
vibration/noise.
2. Lightweight and low-inertia.
3. Long torsion component life.

Applicable Vehicle

1. Drive system for medium to high torque 1. Reduced vibration/noise for all drive
ranges. Reduced vibration/noise.
systems from low to high torqueranges.
2. Lightweight and low-inertia.
3. Long product life for torsion component. 2. Superior performance compared tointegral hub.

FF gasoline vehicle

FR gasoline vehicle

Diesel vehicle* Some features may not be applicable.

Clutch Cover Characteristics[Extended Product Life][Improved Clutch Release Performance][Smoother Engagement]

Reduced lever wear by heat treated diaphragm spring.
Reduced load fatigue by performing the hot-setting process on the diaphragm spring.
Improved clutch-release performance by using a ribbed diaphragm spring.
Improved clutch-release performance by using a DST (Diaphragm Spring Turnover) type clutch cover.
Improved shudder resistance by enhanced accuracy in both the bearing adherence strengthand pressure plates movement.

<Clutch Cover Types>
Spring TypeClutch Release Method

Diaphragm Spring
Push Method
Pull Method

Coil Spring
Push Method

Characteristics
1. Long lasting DST type of clutch coverprovides excellent clutch-release
performance.
2. Lightweight and compact.

Applicable Vehicle

1. Superior clutch-release efficiency.
2. Reduced clutch pedal pressure.

1. Superior clutch-release efficiency.
2. Easy replacement.

Applicable in a broad range of Applicable in high-output vehicles
vehicle types from sub-compact (high performance vehicles, etc.).
vehicles to medium size trucks.

Applicable in small and mediumsized trucks.
Ideal for diesel applications.

* Some features may not be applicable.

12Diagnostic Manual

3

Operation Diagram

The most common clutch type is the dry-plate friction clutch. A single friction
plate (clutch disc assembly) is placed between the flywheel and pressure plate(located inside the clutch cover assembly). The pressure plate is pressed against
or lifted away from the disc to transmit or cut off engine power.

Engaged

Disengaged

Input Shaft
Flywheel
Clutch DiscClutch Pedal

Release Bearing

Release Fork
Crank Shaft
Diaphragm Spring
Clutch Cover
Pressure Plate

Clutch pedal released

Clutch pedal depressed

The basic components of a clutch system includes the clutch cover assembly(pressure plate, diaphragm spring, cover, etc.), clutch disc assembly, flywheel,
release bearing, and release fork. The clutch disc is located between the flywheel
and pressure plates and is connected to the transmission gears by the main drive
shaft (input shaft).

13

4Structure and Components

Clutch Disc Assembly

Facing Rivet

Disc Plate

Disc Spring

Thrust Plate

Torsion Spring
CushionDisc HubTorsion Seat

WasherHub Stopper

Clutch Facing

Cone Spring

14

Clutch Facing

Sub PlateDiagnostic Manual

Clutch Cover Assembly

Rivet

Diaphragm Spring

Pivot Ring

Pressure Plate

Strap

Retracting Spring

15

Cover

Pivot Ring

Balance Weight5

Installation Procedure1

2
Use caution in the disassembly of the transmission
and clutch components from the engine.

Clean the Input Shaft.

4 Use the clutch alignment tool to locate the clutch disc with the input bearing while tightening
the clutch cover bolts. Tighten bolts with torque wrench in a diagonal (star) pattern.

Tightening Sequence

Operation Precautions
Do not drop clutch components.

Deformation of the strap or cover willcause failure of the clutch.

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NormalNormalDamagedDamagedDiagnostic Manual

3
Apply appropriate amount of grease on the input shaft and disc spline.

5
Confirm evenness of the diaphragm
springs (within 0.5mm or 0.02inch).

Align the input shaft
correctly with the clutch disc.
Incorrect installation will cause problems
such as damage to the clutch disc.

Key Points for Preventing Failure
1. Refer to instructions and specifications in
the Manufacturer's Service Manual.
2. Do not force or drop parts.

Always follow instructions
to prevent clutch failure.

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6

Troubleshooting 1
1 Slipping Related Problems

Condition:

Oil or similar substance is on the friction surface of the facings.
Disc Related Causes

Cover Related Causes

Other Causes

Cause:

1. Transmission oil or engine oil has leaked onto the facings.
2. Insufficient verification at the time of installation.
3. Problem with vehicle.

Cure:

1. Inspect and repair transmission and/or engine.
2. Replace disc with new part.

Condition:

Facings are worn.
Disc Related Causes

Condition:

Cover Related Causes

Other Causes

Cause:

1. Facings have reached the end of its wear life.
2. Facings have been scorched due to excessive partial clutch
engagement, excessive 2nd gear starts, or excessive
downshifting, etc.
3. Improper driving method.

Cure:

1. Improve driving method.
2. Replace disc and cover with new parts.

Facings have broken.
Disc Related Causes

Cover Related Causes

Other Causes

Cause:

1. Facings have burst due to rapid change in torque(i.e.: mis-shifting or speed shifting).
2. Vehicle was driven with scorched facings.
3. Improper driving method.

Cure:

1. Improve driving method.
2. Replace disc and cover with new parts.

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Diagnostic Manual

Condition:

Pressure of the diaphragm spring is weak.
Disc Related Causes

Cause:

Cover Related Causes

1. Spring function of the diaphragm spring has degraded dueto heat fatigue.
2. Wrong part was installed.
3. Improper driving method.
1. Improve driving method.

Cure:

2. Replace cover with correct part.
3. Replace disc and cover with new parts.

Condition:

Misalignment or malfunction in the release mechanism.
Disc Related Causes

Cover Related Causes

Other Causes

Other Causes

Cause:

1. Release bearing remains connected to the diaphragm spring (partial engagement).
(Cable tension changes with use, making the clutch more susceptible to slipping.)
2. Misalignment at time of installation.

Cure:

Readjust the release mechanism.

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6

Troubleshooting 2
2 Clutch Drag Related Problems

Condition:

Splines are scratched, dented, or damaged.
Disc Related Causes

Condition:

Other Causes

Cause:

1. Input shaft was scratched or other damage occurred to thesplines when installing the transmission, resulting in sliding
problems or a deformed disc plate, causing significant runout.
2. Installation error.

Cure:

1. Replace disc and cover with new parts.
2. Ensure centering when installing transmission.

No grease on splines.
Disc Related Causes

Condition:

Cover Related Cause

Cover Related Cause

Other Causes

Cause:

1. Grease was not applied or insufficiently applied when
installing the clutch disc, resulting in sliding problems.
2. Installation error.

Cure:

Apply grease to the disc splines.

Deformed clutch disc.
Disc Related Causes

Cover Related Cause

Other Cause

Cause:

1. Misalignment of the crankshaft and input shaft caused awobble in the rotation (figure-8 rotation), deforming thedisc so that power is transmitted even when disengaged.
2. Installation error.

Cure:

1. Replace disc and cover with new parts.
2. Ensure centering when installing transmission.

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Diagnostic Manual

Condition:

NormalStraps or other components are deformed.
DamagedDisc Related Causes

Condition:

Cause:

Cause:

Cure:

Replace cover with new part.

Cover Related Causes

Other Causes

1. Insufficient fluid (leaks, etc.) in clutch hydraulic parts.
2. Incorrect cable adjustment.
3. Release fork was installed incorrectly.
4. Misalignment at time of installation.

Cure:

Readjust the release mechanism.

Condition:

Excessive run-out on flywheel.
Disc Related Causes

Cover Related Causes

Cause:

Installation error.

Cure:Realign or replace the flywheel.

Other Causes

1. Strap has been deformed or the retractable spring has beenbroken due to dropping the part.
2. Damaged in shipping.
3. Mishandling or installation error.

Release mechanism misaligned or failed.
Disc Related Causes

Cover Related Causes

Other Causes21

6

Troubleshooting 3
3 Shuddering and Chattering Problems(Clutch Mechanism Failure and Abnormal Friction Surface)
Condition:

Oil or similar substance is on the friction surface of the facings.
Disc Related Causes

Condition:

Other Causes

Cause:

1. Facing was touched with oily hands when replacing thepart.
2. Excess spline grease was thrown onto the facing due tocentrifugal force.
3. Improper installation.

Cure:

1. Replace disc with new part.
2. Do not contaminate facing with oil.

The friction surface of the facings is showing heat degradation.
Disc Related Causes

Condition:

Cover Related Causes

Cover Related Causes

Other Causes

Cause:

1. Facing has reached the end of its wear life.
2. Facing has been scorched due to excessive partial clutch
engagement, excessive 2nd gear starts, or excessive
downshifting, etc.
3. Improper driving method.

Cure:

1. Replace disc and cover with new parts.
2. Improve driving method.

Abnormality seen in the friction surface of the pressure plate.
Disc Related Causes

Cover Related Causes

Other Causes

Cause:

1. Friction surface of the pressure plate has become glazed.
2. Installation error.
3. Improper driving method.

Cure:

1. Replace cover with new part.
2. Replace clutch cover when replacing disc.
3. Improve driving method.

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Diagnostic Manual

Condition:

Abnormality seen in the friction surface of the flywheel.
Disc Related Causes

Cover Related Causes

Other Causes

Cause:

1. Friction surface of the flywheel has become glazed.
2. Installation error.
3. Improper driving method.

Cure:

1. Replace flywheel.
2. Inspect and service flywheel when necessary.
3. Improve driving method23

6

Troubleshooting 4 5
4 Abnormal Noises and Inability to Drive (Broken Clutch)

Condition:

1. Broken disc component.
Disc Related Causes

Condition:

Cause:

Cure:

1. Replace disc and cover with new parts.
2. Ensure centering when installing the transmission.

2. Broken disc component.
Cover Related Causes

1. Misalignment caused disc to break and engine power is not
being transmitted.
2. Installation error.

Cure:

Replace disc and cover with new parts.

Cover Related Causes

Other Causes

Cause:

1. Excessive partial clutch engagement or mis-shifting caused the facing to burst.
2. Improper driving method.

Cure:

Improve driving method.

A cover component has broken.
Disc Related Causes

Other Causes

Cause:

3. Broken disc component.
Disc Related Causes

Condition:

Other Causes

1. Misalignment of the crankshaft and input shaft or otherproblem caused disc breakage, ejecting springs and othercomponents.
2. Installation error.

Disc Related Causes

Condition:

Cover Related Causes

Cover Related Causes

Other Causes

Cause:

1. Significant run-out on the flywheel broke the cover’s retracting spring.
2. Improper installation.

Cure:

Replace flywheel with new part.

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Diagnostic Manual

Condition:

The edge of the diaphragm spring shows abnormal wear.
Disc Related Causes

Cover Related Causes

Other Causes

Cause:

1. Misalignment of the crankshaft and input shaft or the
bearing caused the edge of the diaphragm spring to wear,
preventing smooth rotation of the bearing.
2. Installation error.

Cure:

1. Replace cover with new part.
2. Ensure centering of the bearing.

5 Clutch Cover Selection Errors and Clutch Mechanism

Operation Failures
Condition:

Incorrect part number was installed.
Disc Related Causes

Cover Related Causes

Cause:

1. Wrong part was installed.
2. Incorrect part number selection.

Cure:

Replace cover with the correct part.

Condition:

Other Causes

Malfunction of the release mechanism is causing sliding resistance.
Disc Related Causes

Cover Related Causes

Other Causes

Cause:

1. Resistance is causing rough movement of the release fork, installation rod, or cable.
2. Installation error.

Cure:

Readjust the release mechanism.

25Diagnostic Manual

7

Precautions in Handling
Caution:Failure to observe the following precautions could lead to clutch failure, accidents, and injury.

Do not place more than four boxes
in one stack.
If there are different box sizes, place
the largest on the bottom.

Do not use a clutch that has been
dropped.

ReasonReasonReasonInappropriate stacking cancause boxes to crush and cause
clutch damage.

The parts that sustained theimpact could be damaged andcause problems (e.g. clutchdrag).

Oil on the friction surface orrust caused by water could leadto problems (e.g. clutch drag orslipping).

Remove excess grease when installing
disc.

Tighten cover bolts in a diagonal(star) pattern. Never use an impact
wrench.

When tightening the cover, usebolts and torque specified from thevehicle manufacturer, using a torquewrench.

ReasonReasonReason

Excess grease on the friction
surface can cause slipping or
shuddering.

If bolts are torqued in one step,
an impact wrench is used, or ifbolts are tightened in a circularpattern (not diagonally), it cancause clutch drag or shuddering
through lever misalignment.

Bolts can break if the vehicle
manufacturer's specified bolts
are not used or not tightened
to torque specifications.

6

1

3

4

5

2

26

Do not use a clutch that was
contaminated with water or oil.