Valeoscope Commercial Vehicles Clutch 2020

Diagnosis Hard gear shifting

3.1.3 Reasons due to the clutch

1. Locking ring deformed

2. Worn or broken attachement systems

3. Worn diaphragm fingers

Vehicle behavior ●● Difficulty in gear shifting when the vehicle is running or when it is stopping. ●● Gear noise (scratching noise) when engaging reverse gear. ●● Difficult or impossible to engage or disengage a gear. ●● Vehicle jumps slightly when the gear engages from idle position. Reasons ●● Release bearing

Parts inspection The release bearing connection system is disconnected, broken or snatched. Vehicle behavior ●● Impossible to shift the gear. Reasons ●● Assembly or fitting mistake. Parts damaged during assembly. The release bearing connection part is not well positioned. The clutch disc has been fitted in a wrong position. ●● Snap ring or lock ring Not well positioned in the bearing groove or deformed during assembly.

Parts inspection The connecting system of the snap on/off release bearing is disconnected, worn, broken or snatched. Vehicle inspection The release bearing is disconnected from the diaphragm.

Clutch inspection Diaphragmfingers are worn by the bearing (Incrustation, wear, or breakage of diaphragm fingers).

disconnection wrong sliding ●● Cover assembly

Worn diaphragm fingers

cover deformation pressure plate broken straps straps deformation facings dirty with grease shock on facings shock on disc shock on splines

Vehicle behavior ●● Hard gear shifting. ●● Clutch Pedal vibration. Reasons ●● Wrong condition or incorrect adjustment of linkage ●● Damaged bearing ●● Engine malfunction ●● Severe usage ●● Fitting of a release bearing without self centring Diagnosis ò ò Insufficient release bearing preload (wear due to slippage between bearing and diaphragm fingers) ò ò Wrong condition of linkage (fork, articulation) ò ò Wrong Cover assembly setting ò ò Seized bearing ò ò A worn or wrongly calibrated engine will generate high vibrations at bearing/diaphragm contact ò ò The clutch fitted is not the right one ò ò The wear of diaphragm fingers depends on the clutch usage (very common in urban areas) Attention Ɂ Ɂ Only use products from a supplier delivering Truck manufacturers.. Advice   Checktheconditionofclutchlinkageandmake adjustment according to manufacturer’s recommendations.  Check the effectiveness of each operation of the release bearing preload system.

●● Clutch disc

Diagnosis ò ò The diagnosis can be done by measurement or observations through clutch housing opening. Attention Ɂ Ɂ Never clean the parts before their inspection. Advice   Parts inspection is performed after gearbox and clutch disassembly (Refer to examination of used clutch Chapter 4).

Fixed Release Bearing

Reasons ●● Poor condition of clutch linkage, insufficient bearing preload on diaphragm ●● Intensive engine vibrations ●● Wrong locking of release bearing attachment system during assembly ●● Forget to unlock the release bearing during gearbox disassembly (attachment system snatch when pulling away the gearbox) Attention Ɂ Ɂ Check the clutch linkage conditions, the engine and their adjustments. Advice   Follow specific Valeo fitting instructions for snap on/off release bearing. (Refer to maintenance tips).

Advice   Respect Valeo installation instructions (Refer to Valeoscope fitting tips).

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