348 - Excessive clutch pedal travel? | FerrariChat
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348 Excessive clutch pedal travel?

Discussion in '348/355' started by Finpat, Aug 7, 2023.

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  1. Finpat

    Finpat Karting

    Sep 17, 2021
    227
    Finland
    Full Name:
    Kari Lehtinen
    #1 Finpat, Aug 7, 2023
    In my 1991 TS clutch engages rather high, perhaps at 25% of pedal travel on the top and the rest seems to be an empty movement. And when depressing the pedal to the bottom the clutch makes similar noise as with worn out TO bearing. There is no extra noises present when clutch is operated at about the top 25% of the travel and it seems to fully engage at that range.

    As my TO bearing has been freshly changed I have a theory that when pedal is fully extended to the bottom actually slave cylinder over extends the clutch fingers which then start to make noise.

    I also checked the pedal travel adjustment screw at the pedal box and it has screwed about to the bottom i.e. making pedal travel as short as it can be without changing to a taller screw.

    Questions:
    1) Is my hypothesis about over extended clutch slave cylinder movement valid in the context of 348?
    2) Is 348 clutch designed to engage only in a short range of total movement or do I have some interesting issue?
    3) Has anybody limited pedal travel at the bottom with taller adjustment screw or similar setup?
     
  2. Ferrarium

    Ferrarium F1 Veteran
    Rossa Subscribed

    Jul 28, 2018
    5,716
    Central NJ
    Full Name:
    Eric
    #2 Ferrarium, Aug 7, 2023
    I just redid my whole clutch in my 90 TS, I put in:
    1. Whole new AP Racing stack (Double plate)
    2. New Billet Flywheel
    3. New Hill TOB
    4. Pressure bled the clutch with Motul.
    From the bottom of the clutch stroke coming back up, it engages at the top of first 1/3 up real lightly, starts grabbing middle third and just into the top third its grabs like a mofo, the rest of the top travel is just overhead. Have to slip the clutch middle before it grabs like a lock just at the start of the top third. Clutch is freaking awesome when sorted.

    Ther is nothing in my car that I say "ehh that does not seem right" especially noy the clutch, may be one of the best clutches I have driven and I have driven a lot of them. GB is ehhh, typical of that era but the clutch and the clutch pedal stroke is bliss.
     
  3. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    9,581
    #3 Mitch Alsup, Aug 8, 2023
    a) There are adjustments to raise or lower the engagement point.

    b) a high engagement point is indicative that the clutch has wear.
     
  4. Finpat

    Finpat Karting

    Sep 17, 2021
    227
    Finland
    Full Name:
    Kari Lehtinen
    #4 Finpat, Aug 9, 2023
    a) How the engagement point can be adjusted with 348 hydraulic clutch? (Sorry for a newbie question.)
    The pedal travel limitation/adjustement screw by the pedal box is at the position which limits the travel maximally i.e. shortest possible pedal travel.

    b) Is 348 hydraulic clutch system different than most and doesn't compensate for clutch wear? Anyway, I have a fresh clutch setup in place so that should not be a problem.
     

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