VSAO _ Clutch diagnostic folder_VF_EN[108]

CLUTCHES Diagnostic Data Sheets Warranty Returns

FILE Clutch diagnostic

INTRODUCTION This file contains fault-finding data sheets with some useful tips that will help you to quickly identify a problem with a clutch.

How to use this diagnostic file 1. Understand your customer's perception of the fault 2. Visually analyze the returned part 3. Select the right data sheet in order to solve the problem

If none of the data sheets match the fault, then please send us a warranty claim form so that we can find a solution to your problem.

ENVIRONMENT

THE ENVIRONMENT OF A CLUTCH

Receiver

Piston

Drive plate

Release fork

Main gearbox shaft

Release bearing

Crankshaft

Mechanism

Engine flywheel

FUNCTIONS

THE MAIN FUNCTIONS OF A CLUTCH

BASIC

COMFORT

PROTECTION

Transmit all the torque. Couple and uncouple the engine and the gearbox.

Enable the driver to control the torque to be transmitted. Change gear smoothly. Reduce the vibrations between the engine and the gearbox.

All clutches are designed to slip in the event of excessive torque in order to protect the engine and the transmission. The clutch and the engine flywheel must be capable of dissipating heat. Premature failures usually result in clutch slippage.

DEFINITION

ENGINE ACYCLISM: DEFINITION

Internal combustion engines can be characterized by the alternating compression and combustion phases. The cyclic pressure variations inside the cylinder result in variations in the speed of rotation. These variations are called acyclism. Acyclism causes an uneven speed of rotation of the crankshaft. This is also called torsional vibration.

GOOD TO KNOW

Perceived noise can be caused by poor filtration of vibrations and acyclism. It is the result of the rotation of the crankshaft + engine flywheel + clutch assembly, which is subject to cyclical irregularities.

RECOMMENDATIONS

INSTALLING A CLUTCH GENERAL RECOMMENDATIONS

1. BEFORE ASSEMBLING/REPLACING: Clearly identify your customer's problem • by asking precise questions that identify the symptoms or • by test driving the vehicle yourself

Symptoms with a conventional clutch

Difficulty in starting

Juddering

Slipping: the car does not

speed up, even when the engine speed increases

Noise : noise when in neutral or whenever shifting gear Noise from the gearbox and from outside the gearbox

Difficult gear shifts : difficulty shifting gear from neutral or when driving

Impossible to change gear : the gears cannot be engaged

Stiff pedal

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RECOMMENDATIONS

INSTALLING A CLUTCH GENERAL RECOMMENDATIONS

2. NO TIGHTENING TOOLS are required to install certain KIT4P and FullPACK DVA kits, and SAT clutches. Otherwise, follow the recommendations in the manual.

Gear box side x

3. Install the disk THE RIGHT WAY ROUND

Engine side

GEARBOX SIDE PP GB SIDE GETRIEBESEITE LATE CAMBIO T/M SIDE

ENGINE SIDE FLYWHEEL SIDE FW SIDE ENGINE SIDE SCHWUNGRAD SEITE

ENGINE FLYWHEEL SIDE

GEARBOX SIDE

*Gearbox side = mechanism side

RECOMMENDATIONS

INSTALLING A CLUTCH GENERAL RECOMMENDATIONS

4. ALWAYS REPLACE THE SCREWS when replacing the engine flywheel.

5. ALWAYS TIGHTEN (in a star pattern) to torque and, if necessary, to the specified angle (refer to the instructions).

Example on a VW Golf 4: 60 Nm + angle of 90°

6. TIGHTEN the mechanism TO A TORQUE of between 15 and25 Nm, depending on the model. 7. ALWAYS GREASE. Use the grease provided in the kit, if included (5 g recommended).

8. ALWAYS REPLACE THE HYDRAULIC RELEASE BEARING and bleed

RECOMMENDATIONS

9. RECOMMENDED CHECKS: the right methods

CLUTCH

POWERTRAIN

Parts to be checked

Parts to be checked ENGINE SUPPORT UNIVERSAL JOINT, GAITERS

Check:

Check:

CRANKSHAFT LIP SEAL

CHECK FOR OIL LEAKS

NO EXCESSIVE PLAY

GENERAL CONDITION CONDITION OF THE SPLINES (worn or damaged)

GENERAL CONDITION

DRIVER BEARING, FLANGES

SPLINES IN THE MAIN GEARBOX SHAFT

SILENT BLOCK

NO EXCESSIVE PLAY

MOUNTING OF THE ENGINE FLYWHEEL ON THE CRANKSHAFT

ANTI-TORQUE TIE RODS

NO EXCESSIVE PLAY

NO FLYWHEEL PLAY

NO TRACES OF GREASE, SURFACE DAMAGE OR CRACKS CONDITION OF THE CONTACT SURFACES BETWEEN THE ENGINE AND THE GEARBOX

GENERAL CONDITION OF THE TEETH

SURFACE OF THE ENGINE FLYWHEEL

STARTER GEARS

CENTERING STUDS AND CONDITION OF THE CONTACT SURFACE BETWEEN THE GEARBOX AND THE ENGINE

WHEEL ROLLER BEARINGS

NO EXCESSIVE PLAY

ENGINE / GEARBOX ALIGNMENT

USE A JACK OR A HOIST

GUIDE TUBE

GENERAL CONDITION

CONTROL SYSTEM

THE FORK MUST SLIDE PERFECTLY

ARTICULATION AND SLIDING MOVEMENT OF THE FORK

SPLINES IN THE MAIN GEARBOX SHAFT

GENERAL CONDITION

EMITTER / RECEIVER

CHECK FOR LEAKS

VIBRATION ABSORBER ON THE PIPING

GENERAL CONDITION

GEARBOX CONTROL RODS

GOOD WORKING ORDER

RECOMMENDATIONS

10. POST-INSTALLATION Check that the clutch is in good working order in FOUR STEPS

1

Disengage and engage the clutch, while selecting every gear. The clutch should engage when the pedal is pressed down about two-thirds of the way from its position at rest.

2

Check for any abnormal noises when engaging and disengaging the clutch.

3

Check for any abnormal noises when in neutral and when accelerating to 2,000 rpm.

4

Check for any abnormal slippage when accelerating.

VALEO = PEACE OF MIND

THE VALEO WARRANTY: all our products are covered by a warranty.

12 months*

HELP WITH THE DIAGNOSTIC: if you have a problem with a broken or defective part, send us your claim form directly and we will deal with your request as quickly as possible.

Your technical expert is available for you vsx-service.mailbox@valeo.com

*The warranty is valid for twelve (12) months after the date of sale to the end customer who uses the vehicle and for thirty-six (36) months after the date of sale by Valeo Service to its customer, as shown on the invoice. The warranty covers products for four (4) years after their date of manufacture.

FAULTS AND TIPS

JUDDERING SYMPTOM: juddering when shifting gear

Abnormal wear on the diaphragm studs

What to do

Identify the problem • in first gear or reverse. • Engage the clutch normally. => the vehicle judders forwards.

Causes: • insufficient pre-load on the release bearing, • gearbox / engine off-center.

The solutions • Cable control with automatic adjustment: replace the cable. • Semi-hydraulic system: replace the receiver. • System with a hydraulic release bearing: replace the release bearing. Check the gearbox centering studs. It is advisable to use a hoist or a jack to align the engine and the gearbox when assembling.

FAULTS AND TIPS

JUDDERING SYMPTOM: juddering when shifting gear

Damaged rivets and linings

What to do

Identify the problem: • in first gear or reverse. • Engage the clutch normally. => the vehicle judders forwards.

Causes: Abnormal friction on the drive plate when re-engaging.

The solutions To install the gearbox:

• keep the mechanical parts aligned with a hoist or a jack until they are fully attached, • check the condition of the contact surfaces and the centering studs, • check the engine / gearbox alignment, • check the tightening torque of the screws around the gearbox.

FAULTS AND TIPS

JUDDERING SYMPTOM: juddering when shifting gear

Centrifuged grease

What to do

Identify the problem: • in first gear or reverse. • Engage the clutch normally. => the vehicle judders forwards

Causes: The lining is polluted by oil or grease.

The solutions

Check the seals and, if necessary, replace: • the lip seals of the engine and the gearbox, • the hydraulic release bearing. Moderately grease the release bearing guide and the fork bearings. Caution: cleaning the lining will not solve this problem.

FAULTS AND TIPS

NOISE SYMPTOM: in neutral or when shifting gear

Grease on the drive plate hub

What to do

Identify the problem: • engine running, vehicle stationary, • noise coming from the gearbox => centrifuged grease on the hub.

Causes: grease reduces the filtering capacity of the clutch, producing an abnormal noise.

The solutions • Replace the clutch, using the grease provided, without any excess. Cleaning will not correct this fault.

FAULTS AND TIPS

NOISE in neutral

Deterioration of the springs

What to do

Identify the problem: • engine running, vehicle stationary, • noise coming from the gearbox. Causes: • excessive acyclism: incorrect engine management, the cylinder compression is not uniform, etc.

The solutions • Tune the engine. •

Check the injection and ignition parts.

FAULTS AND TIPS

IMPOSSIBLE TO SELECT A GEAR AND NOISE

Broken disk

What to do

Identify the problem: •

vehicle with the engine running, impossible to select a gear.

•

Causes: - deformation of the drive plate when installing the gearbox, - the gearbox is significantly off-center, causing the disk to bend or even break.

Oscillating gearbox shaft

The solutions • check the contact surfaces of the gearbox before installing, • align the engine and the gearbox using jacks and/or a hoist, • check the tightening torque of the screws around the gearbox.

FAULTS AND TIPS

DIFFICULT GEAR SHIFTS

Deformed set of tongues

What to do

Identify the problem

vehicle with the engine running,

•

• the gears crunch when shifting. Causes: The deformation of one or more sets of tongues makes it difficult to change gear.

The solutions • Handle the clutch with care. Dropping or mishandling the clutch mechanism can damage a set of tongues.

Tips: • Never start a vehicle in first gear or reverse. • Caution: incorrect gear shifts can damage the tongues.

FAULTS AND TIPS

IMPOSSIBLE TO SELECT A GEAR THE GEARS

Ejected spring

What to do

Identify the problem: • engine running, • the gears cannot be engaged, • the gearbox makes a metallic noise.

The high engine acyclism applies stress to the spring, which is eventually ejected. The ejected spring falls into the moving parts of the clutch mechanism and prevents the gears from being selected.

Causes: • excessive acyclism: incorrect engine management, the cylinder compression is not uniform, etc.

The solutions ● Check the injection and ignition parts. ● Tune the engine and adjust the mapping.

FAULTS AND TIPS

IMPOSSIBLE TO SELECT A GEAR THE GEARS

Worn diaphragm (lack of pre-load)

What to do

Identify the problem: • engine running, • the gears cannot be engaged. Causes: • insufficient pre-load on the release bearing, gearbox / engine off-center. The release bearing wears the diaphragm studs, eventually passing through it and destroying the release bearing. •

The solutions Repair the parts of the control system according to the technology used.

FAULTS AND TIPS

SYMPTOM: the gears cannot be engaged IMPOSSIBLE TO SELECT A GEAR THE GEARS

Broken diaphragm

What to do

Identify the problem: • engine running, • the gears cannot be engaged. Causes: • incorrect control settings, • damaged or bent fork,

Over-travel of the release bearing, causing the diaphragm to tilt too far and beyond its mechanical resistance.

The solutions • Check the condition of the control system: cable, fork, ball joint, emitter and receiver. • With hydraulic or semi-hydraulic technologies, check the travel of the clutch release bearing.