Test results

Visually inspect whether the problem is accompanied by an oil leak from the gearbox/differential.

Press the clutch pedal and check whether the noise increases.

Check the gearbox/differential oil level

Move on to Step 1

1. Oil leak detected from the gearbox

2. The noise disappears or decreases considerably with the clutch pedal pressed: the noise comes from inside the gearbox

3. Oil level too low

1. Proceed as instructed

 See table X015 GEARBOX/DIFFERENTIAL OIL LEAKS

2. Proceed as instructed

 See table S015 NOISE WHILST DRIVING

3. Restore the correct level and carry out a road test

 Op. 0010T40 CHANGE MANUAL GEARBOX OIL

If the fault persists, move on to Step 1

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

Move on to Step 2

1. Gearbox main shaft hub faulty

2. Clutch plate hub bushes faulty

1. Replace the gearbox main shaft

2. Restore the correct lubrication for the bushes. If necessary, replace the clutch plate

 Op. 1810A20 CLUTCH - R + R

Check:

- Clutch plate wear;

- Fouling (oil or grease) of the clutch plate;

- That there is no distortion of the clutch plate;

- That there is no damage to the pressure plate diaphragm spring.

End of diagnosis

1. Clutch plate or pressure plate faulty

2. Presence of oil or grease

1. Replace the clutch plate

 Op. 1810A20 CLUTCH - R + R

2. Also replace the gearbox input oil seal