clutch/gearbox issue 348 Mondial | FerrariChat

clutch/gearbox issue 348 Mondial

Discussion in 'Technical Q&A' started by dsvitesse1, Oct 9, 2017.

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  1. dsvitesse1

    dsvitesse1 Rookie

    Oct 9, 2017
    4
    Full Name:
    Harry Martens
    Hi,

    I am facing a problem with a fully rebuild gearbox and clutch from a 348. Dual disk with Voight flywheel.

    Rebuild gearbox fully and can select all gears. After first run we discovered the plates were slipping. Did send unit back to friction specialist. Had to do that twice. Now that's ok.
    When on floor we can select all gears and with wheels of ground we can put in any gear.
    On street, with engine idle, can select first or/and reverse. Take of in first but than not able to shift to any other gear. Not sure where to look any more. Imho, the diafragma spring is not flat enough when bolted on flywheel.

    Any thoughts here?

    Many thanks in advance, I am in the Netherlands and my English is poor.


    Harry Martens
    www.ds-vitesse.com
     
  2. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    12,661
    San Carlos, CA
    Full Name:
    Mitchell Le
    If you can select all gears with the engine off, then the problem is not inside the box. Most likely it is clutch related. Look there.
     
    dsvitesse1 likes this.
  3. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    26,288
    socal
    Agree with Mitchell. Look in workshop manual. It lists all clutch pack specs. If you are not using a new OEM clutch pack replacement then you must measure everything to make sure the rebuilder did the job correctly. They rarely do. Check the open and closed measurements of each clutch disk. If your pressure plate and flywheel and intermediate plate are in spec the problem is in the discs. 95% of rebuilder screw up are in the clutch discs. If the closed measure of the disc is too big you can have the rebuilder wear off some disc to be in specification.
     
  4. dsvitesse1

    dsvitesse1 Rookie

    Oct 9, 2017
    4
    Full Name:
    Harry Martens
    Hi, thanks for reply. Strange thing is that I can select all gears with engine idle. I can take off in 1st or 2nd and reverse, but when driving I am not able to shift up to 2nd or 3rd.

    cheers,
     
  5. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    26,288
    socal
    You are not getting full disc release. Causes:
    poor bleed
    Throw out bearing
    Disc improper size/clearance
    Other faults like broken bent pressure plate fingers, failed clutch master
     
  6. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    12,661
    San Carlos, CA
    Full Name:
    Mitchell Le
    When you say you cannot select any gears while moving, do you mean the gear shifter will not go into that slot, or it goes in that slot but it does not act like it is in that slot? Does the Mondial T have shift rod, or cable? Did you mess with that?
     
  7. ago car nut

    ago car nut F1 Veteran
    Silver Subscribed

    Aug 29, 2008
    5,246
    Madison Ohio
    Full Name:
    David A.
    Does the dual disc clutch have shims between the plates? Maybe it needs shim correction?
     
  8. dsvitesse1

    dsvitesse1 Rookie

    Oct 9, 2017
    4
    Full Name:
    Harry Martens

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