939003588 - E003 CLUTCH VIBRATING OR JERKING

0PRELIMINARY CHECKSALL OKPROBLEMS ENCOUNTEREDACTION

  • Carry out a driving cycle simulating a hilly/urban route with frequent gear changes and departures from a standstill letting the engine and, in particular, the clutch reach operating temperature.

  • Carry out departures from a standstill with the engine speed not below 1000 rpm releasing the clutch pedal gradually simulating the vehicle driving in traffic at a speed of around 10-20 km/h for a few seconds.

  • Carry out departures at different engine speeds, hot and cold, at different gradients.

  • Let the vehicle reach a constant speed (about 1000 rpm in 4th gear) and, with the clutch pedal released, accelerate quickly by fully depressing the accelerator pedal.

  • Check whether there is irregular advance (jerking).
Move on to Step 1Presence of irregular advance (jerking)Check that the engine supports are properly secured.
1CLUTCH LEVER TRAVEL CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check, inside the engine compartment, that when the clutch pedal is pressed the clutch control lever on the gearbox completes the correct travel.Move on to Step 41.Clutch lever on gearbox travel incomplete.1. Move on to Step 2
2. Clutch pedal free play insufficient.2. Move on to Step 2
2CLUTCH PEDAL CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Clutch pedal disconnected from transmission    Op. 3330B26 CLUTCH PEDAL - R+R check that the travel is free and there is no sticking or hardening.Move on to Step 3Clutch pedal clearance or hardening.Replace the pedal    Op. 3330B26 CLUTCH PEDAL - R+R
3ENGINE AND GEARBOX CASING ALIGNMENT CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check for the centering pins on the engine block checking whether the flexible couplings have become loose if the centering pins are not present.Move on to Step 41. The centering pins are missing.1. Correct the problem by inserting the centering pins
2. The flexible couplings have become loose.2. Restore the correct closure.
4PLATE LEVER AND BEARING CHECK (WITH GEARBOX REMOVED)ALL OKPROBLEMS ENCOUNTEREDACTION
After the gearbox has been removed, check that there is no hardening of the lever (as a result of dirt or insufficient greasing) and that the plate bearing slides freely in its housing and shows no signs of damage.Move on to Step 5The presence of dirt or wear due to insufficient greasing does not allow the plate bearing to slide correctly.Replace the faulty or damaged components.
5CLUTCH ASSEMBLY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Visually inspect the state of the clutch assembly, making sure there are no breaks and/or signs of overheating on the plate, obvious deterioration of the driven disc or grease/oil on the friction surfaces.Measurements using the gauge as in the manual.Move on to Step 61.Obvious deterioration of the clutch disc and/or plate broken.1. Replace the assembly    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
2. Disc distorted.2. Replace the clutch plate    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
3. Plate with vitrified seal.3. Replace the clutch plate    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
4. Oil or grease on the disc.4. Remove the oil or grease.
5. Break at the base of the clutch disc friction material support segments.5. Replace the clutch plate    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
6. Flexible coupling system seriously damaged.6. Replace the mechanism    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
5CLUTCH ASSEMBLY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Visually inspect the state of the clutch assembly, making sure there are no breaks and/or signs of overheating on the plate, obvious deterioration of the driven disc or grease/oil on the friction surfaces.Measurements using the gauge as in the manual.Move on to Step 61.Obvious deterioration of the clutch disc and/or plate broken.1. Replace the assembly    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
2. Disc distorted.2. Replace the assembly    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
3. Plate with vitrified seal.3. Replace the assembly    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
4. Oil or grease on the disc.4. Remove the oil or grease.
5. Break at the base of the clutch disc friction material support segments.5. Replace the assembly    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
6. Flexible coupling system seriously damaged.6. Replace the assembly    Op. 1810A24 CLUTCH - R + R WITH GEARBOX REMOVED
6CLUTCH SLIDING SPLINED HUB CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the following, in order:

  • for excess grease on the clutch plate hub bushes and the gearbox main shaft;

  • the condition of the main shaft hub.
Move on to Step 7Main shaft damaged, hub worn, excess grease on the bushes.Replace the hub and/or main shaft
7FLYWHEEL CONDITION CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the condition of the flywheel.In particular, check:

  • the state of the surface;

  • wear;

  • cuts;

  • signs of overheating;

  • presence of grease/oil on the surfaces.
End of diagnosis1. Flywheel damaged.1. Replace the flywheel    Op. 1024B10 ENGINE FLYWHEEL - R + R FOR VERSIONS WITH MANUAL GEARBOX
2. Presence of dust in the flywheel friction seal.2. Remove the dust from the flywheel friction seal.