Launch x431 clutch wear incorrect

Discussion in 'Technical Q&A' started by epb0, Jan 26, 2020.

  1. epb0

    epb0 Rookie

    Feb 27, 2015
    I recently had an X431, and I realize that the clutch wear calculation on my 4200 is incorrect.

    Have you noticed this problem on others vehicles, Maserati or Ferrari in particular ?
    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):

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    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

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    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:

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    The system indicates 1 more decimal place. The calculation from these values gives 58.96%, everything is fine!

    4 / Diag X431

    Always the same car:

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    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 the constant used for the % wear is incorrect (7mm ALD 5.6mm).
    SingleClutch and brogenville like this.
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  3. epb0

    epb0 Rookie

    Feb 27, 2015
    New test today with Maserati 11.05 release (instead 11.00): no improvement, always same wrong constant.
  4. tstuli

    tstuli Karting

    Jun 12, 2018
    Yes they are using the wrong clutch thickness. You need to redo the calc with the 5.6mm manually.

    Sent from my iPhone using Tapatalk
  5. spider348

    spider348 Formula 3
    Silver Subscribed

    Nov 3, 2003
    Full Name:
    Interesting to say the least.
    Have been struggling to understand the convoluted readings from my clone tool using Diagzone software.
    Reading taken last evening;
    2001 Ferrari 360. Latest TCU 211023 I believe.
    Self Calibrated New Clutch Position 14.06 mm
    Self Calibrated Current Clutch Position 14.55 mm
    Degree of Clutch Wear 15162(No Idea What This Relates To)

    Amount of wear appears to be 0.49 mm

    Don't know 360 clutch factor to use. Recall someone posting 8 mm?

    If Factor 8mm wear 6%. Appears very low for 3k mile F1 clutch.
  6. epb0

    epb0 Rookie

    Feb 27, 2015
    Yes, it's that I explain before ;-)
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  8. epb0

    epb0 Rookie

    Feb 27, 2015
    I don-t know constant to use for 360.
    Your wear is for me right. I count 1% for 1000km if you drive normaly.
  9. SingleClutch

    SingleClutch Karting

    Apr 19, 2019
    Full Name:
    I bought an X431 about a month ago and haven't hooked it up to my F430 yet. Maybe I'll do that today and see what mine says. I'm pretty sure my clutch will need to be replaced sometime soon, unfortunately.

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