Valeoscope Commercial Vehicles Clutch 2020

Diagnosis Noise and vibration

5. Broken facings, broken cushion pad

6. Disconnected pre-damper ª ª Refer to chapter 3.1

ò ò Parts of broken springs may jump out of the clutch disc and stick onto the clutch facing, or between the diaphragm and the pressure plate. Attention Ɂ Ɂ Check that the engine is in good condition.

Diagnosis ò ò Contaminants brought by cleaning liquids ò ò Grease has become liquid because of overheating (extreme use of the clutch). It can be checked visually through the holes of the clutch housing. Advice  ą ą Check and maintain the linkage regularly. ą ą Adjust the linkage according to the manu- facturer’s recommendations.

7. Friction marks on the retainer plates ª ª Refer to chapter 3.2

Advice   Make sure that the clutch disc matches the vehicle model.

8. Broken retainer plates ª ª Refer to chapter 3.1

Broken facing

9. Broken disc ª ª Refer to chapter 3.2

4. Worn or broken clutch disc Clutch inspection Clutch disc or damper box destroyed.

3. Broken damper spring

3.4.2 Gearbox with synchromesh ª ª Refer to chapter 1

Vehicle behavior ●● Noise in clutch ●● No torque transmission (the vehicle cannot move) Reasons ●● Wrong part number, improper clutch disc ●● Vehicle characteristics modified

Clutch inspection Burst facings together with cushion pad (in case of flat flywheel). Vehicle behavior ●● Sudden vehicle stop, after a gear shifting ●● Noise in clutch Reasons ●● Rotating speed of gearbox input shaft is too high (rpm overrun). ●● Weakened facings (material destroyed, facing too thin, non conformed riveting). Diagnosis ò ò Destruction of facing by overheating ò ò Facing wear exceed the admitted tolerance ò ò Fixing of the facings not in specifications ò ò Mis-shifting ò ò Driving down hill, declutched with a low gear engaged Attention Ɂ Ɂ Replacement of the clutch facings is done only by the clutch manufacturers. Advice   Clutch facing material and the riveting process are critical to insure clutch performance and clutch disc life.

3.4.3 Facing bonded on steel-back ª ª Refer to chapter 1

Broken damper spring

Clutch inspection ●● Broken damper spring ●● Large wear of the clutch disc Vehicle behavior ●● Noise in clutch housing ●● Wrong clutch release Reasons ●● Broken spring ●● Wrong disc part number fitted ●● High engine vibrations Diagnosis

Worn or broken clutch disc

Diagnosis ò ò The damper is too weak to transmit the engine torque. ò ò Changing the injection powertrain settings and mounting a retarder. Such modifications can lead to intensive vibrations that might affect the durability of the clutch disc.

Attention Ɂ Ɂ Check the vehicle original configuration.

ò ò The engine tensional fluctuations can generate intensive vibrations which affect the damper durability. ò ò Damper characteristics are not the ones defined for the vehicle.

Advice   Make sure that the clutch disc part number matches with the vehicle type (engine, gearbox…).

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