I recently had an Launch X431, and I realize that the clutch wear calculation on my Ferrari 4200 is incorrect.
So yes, it is not a Ferrari, but there is no reason why it should be different for the prancing horse.
Have other people noticed this problem on other Maserati or Ferrari vehicles?
Do you have diag reports (SDx, MVDCI, Leonardo, Texa or others) where these values appear?
1 / How is wear calculated?
It is quite simply the difference between the current wear and the theoretical maximum.
For this, the system makes the difference between the position of the clutch release bearing when the assembly is new and the current position.
The formula is simply (given in the Maserati training manual):
The thickness of 5.6 mm represents the maximum wear, reduced to the stop. At each friction, this value is of course less important since it is necessary to take into account the presence of 2 discs and the ratio (around 4) generated by the lever arms of the diaphragm of the clutch.
For information, Ferrari indicates 0.8mm of maximum wear for 1 disc for the F430. This value has no reason to be different on the other vehicles in the group.
2 / MDVCI diag report
Diag made in the network with the official tool
The manual calculation from the stop positions (24.60mm and 21.09mm, maximum wear 5.6mm) gives a value of 62.68%.
This is consistent with the 62.76% indicated, the difference must be linked to the rounding to 2 decimal places of the displayed values.
3 / Leonardo diag report
Same vehicle, shortly after:
The system indicates 1 more decimal place. The calculation from these values gives 58.96%, everything is fine!
4 / Launch X431 V+
Always the same car:
Cool, the clutch has rejuvenated!
So, on closer inspection:
((24.53-21.08) / 5.6) * 100 = 61.61%
We then find a coherent value.
5 / Conclusion:
The measurements made with the X431 are good but that the constant used for the% wear is incorrect (7mm ALD 5.6mm).