348 - Broken Diaphragm Spring on my Twin Plate Clutch - Options? | FerrariChat
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348 Broken Diaphragm Spring on my Twin Plate Clutch - Options?

Discussion in '348/355' started by 348Jeff, Aug 21, 2022.

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  1. 348Jeff

    348Jeff Formula 3

    Oct 25, 2011
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    #1 348Jeff, Aug 21, 2022
    On my way home from a fun drive out the gear change started to get difficult. Thankfully just made it home before it became impossible to change gear.

    Decided to investigate yesterday with the result being the discovery that 3 of the fingers on my diaphragm spring are broken. To make matters worse the part is only available as part of a complete clutch unit which is approx £2k here in the UK.

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    And here's the problem - 3 of the diaphragm springs are snapped off - that would of been the clattery sound I heard :-(




    Just for reference here's all the parts of the twin plate clutch NB. there are 3 spacers that are not shown on the video but they are not missing - just forgot to put them back on before making the video.

    I suspect that the worn disc(s) - down to the rivets on one of them is what's caused the spring to break (not really sure TBH).

    https://youtube.com/shorts/fCu--95NuNU

    Closer pics of damage:

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    Clutch prices from Ferrariparts:

    https://www.ferrariparts.co.uk/Diagr...lutch-Controls


    Superperformance do an aftermarket one which is about £400 cheaper

    https://www.superformance.co.uk/348/clutch.html


    Article Ernie (FChat) did about having the fingers repaired

    https://www.diyauto.com/manufacturer...moval-by-ernie

    Ideas, leads free parts ;-') welcome....!!
     
  2. John Glen

    John Glen Formula Junior

    Dec 30, 2009
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    #2 John Glen, Aug 21, 2022
    Check your messages Jeff. I have your part
     
  3. 348Jeff

    348Jeff Formula 3

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    #3 348Jeff, Aug 22, 2022
    Thanks John - I have replied :)
     
  4. AceMaster

    AceMaster Three Time F1 World Champ

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    #4 AceMaster, Aug 22, 2022
  5. 348Jeff

    348Jeff Formula 3

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    #5 348Jeff, Aug 22, 2022
    Last edited: Aug 22, 2022
    Ah that's brilliant - I will make some enquiries as its always handy to know.

    Just read the thread - so is it Rob at UCM Clutch I contact? (I'm having a long day)

    BTW Still very pricey but there is a company in the UK that just sell the clutch cover (including an uprated spring) here:

    https://www.demon-tweeks.com/uk/helix-uprated-clutch-cover-hlx60-5010/

    That was going to be my "if all else fails option"!!

    ps If your reading this John I'm still hoping we can sort something out ! LOL
     
  6. marioz

    marioz Formula 3

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    #6 marioz, Aug 22, 2022
    Rob sold UCM clutch a few years ago.
     
  7. 348Jeff

    348Jeff Formula 3

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    #7 348Jeff, Aug 22, 2022
    As in he sold the company?....so no longer available to supply a spring?
     
  8. marioz

    marioz Formula 3

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    #8 marioz, Aug 22, 2022
    Yes he sold the company.
     
  9. 348Jeff

    348Jeff Formula 3

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    #9 348Jeff, Aug 23, 2022
    Well that's the bad news..... :-(


    But the good news is that John has posted the diaphragm to me today.... :) Cant thank him enough. The Brotherhood strikes again!!

    In the meantime I've just bought new Triton seals and some kluber grease along with teh Hills special tool to remove the Clutch bell housing nut - I'm hoping to regrease my flywheel whilst I'm waiting.

    Today I'll order the new discs so then have all the parts for the job. Cant wait to get it all back together and on the road....ready for the next breakage! LOL
     
  10. m.stojanovic

    m.stojanovic F1 Rookie
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    #10 m.stojanovic, Aug 23, 2022
    Once you install everything, I suggest you check/adjust the clutch pedal travel as per WSM (pages D8-D10). Excessive pedal travel may contribute to premature failure of the diaphragm spring.
     
  11. 348Jeff

    348Jeff Formula 3

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    #11 348Jeff, Aug 23, 2022
    Thanks Mario.

    Took a few photos for reference of my 2 discs (as you can see from the markings they are AP racing from the markings) and the face of one of them is worn down to the rivets :-(

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    As an aside whilst investigating components a double plate clutch has a diameter of 215mm whereas a single plate has one of 240mm
     

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  12. 348Jeff

    348Jeff Formula 3

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    #12 348Jeff, Aug 30, 2022
    copterjon and Qavion like this.
  13. John Glen

    John Glen Formula Junior

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    #13 John Glen, Aug 30, 2022
    Hi Jeff, glad you have received the part so quickly. Hope this will work for you. JGW
     
  14. 348Jeff

    348Jeff Formula 3

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    #14 348Jeff, Aug 30, 2022
  15. John Glen

    John Glen Formula Junior

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    #15 John Glen, Aug 30, 2022
    I didn't need a press when I did mine. If I remember correctly once the large nut was removed the pieces just came apart. Mind you, always handy to have a press.
     
  16. 348Jeff

    348Jeff Formula 3

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    #16 348Jeff, Aug 31, 2022
    Last edited: Aug 31, 2022
    I have read that you can hammer the flywheel out with a drift etc but I want to to remove the bearing out the back of the bell housing too. I have a suspension bush change planned too for over winter so thought it was time I made my life easier! :)

    BTW Did you get your flywheel resurfaced or just put a new clutch unit in? At first I was just going to replace the 2 friction plates but I'm now leaning towards handing the whole clutch unit over to the professionals to have it all balanced/surfaces checked etc.
     
  17. m.stojanovic

    m.stojanovic F1 Rookie
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    #17 m.stojanovic, Aug 31, 2022
    In my case, it was quite easy to knock the flywheel out of the bearing (no hard hammering needed). It was even easier to push the bearing out of the bellhousing - just pushing it with my fingers (snug fit).

    As to the resurfacing of the flywheel and the pressure and intermediate plates, it may not be easy. The drawing below shows my measurements of the "dishes" of the friction surfaces of my twin clutch which appeared to be as machined in the factory (not as worn) as I could still see the machining marks (it was at 12 k miles). I just cleaned up and sanded the surfaces to remove some glazed patches caused by somewhat slipping clutch due to contamination with gearbox oil (triple seals).

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    In any case, check whether your friction plates have similar dishes before you decide to send them for resurfacing. Machining them flat may cause some issues like judder on clutch engagement.
     
  18. m.stojanovic

    m.stojanovic F1 Rookie
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    #18 m.stojanovic, Aug 31, 2022
    Another detail to pay attention to. The splines of the new clutch discs I got had very sharp edges (1st pic) and some burr which could have damaged the O-ring (see example on 3rd pic). I used a small diamond file to remove the burr and slightly round the edges of the splines that come in contact with the O-ring (2nd pic) during the pumpkin installation.

    Sharp edges
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    Rounded edges
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    Damaged O-ring (posted by a member of this forum)
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  19. 348Jeff

    348Jeff Formula 3

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    #19 348Jeff, Aug 31, 2022
    Last edited: Aug 31, 2022
  20. 348Jeff

    348Jeff Formula 3

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    #20 348Jeff, Aug 31, 2022
    I've been looking at replacing the bell housing bearing but its a whopping £156 + 20% VAT from FerrariParts and still £104 + 20% VAT from Eurospares (NSK version).

    I noticed that it gets a mention in the alternative parts thread

    https://www.ferrarichat.com/forum/posts/145832251/

    so been making some enquiries through a SKF distributor in the UK using part no. 3208 A-2RS2TN9/C3HT22 and they enquired with SKF and got response below:


    So I've emailed back asking if they will explain the difference in the RS2 seals. I'll see what they say but I suspect its the difference in temp rating or something similar.
     
  21. 348Jeff

    348Jeff Formula 3

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    #21 348Jeff, Sep 1, 2022
    SKF have replied...

    Any thoughts.....
     
  22. m.stojanovic

    m.stojanovic F1 Rookie
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    #22 m.stojanovic, Sep 1, 2022
    Last edited: Sep 1, 2022
    I have provided all the info I found on this bearing in the thread to which you you have provided a link in your previous post. Basically, the difference between SKF 3208A-2RS2 TN9/C3 HT22 ($$$, only from Ferrari parts suppliers) and the easily available SKF 3208A-2RS1 TN9/C3 MT33 ($$) is that the grease and seals of the HT22 are good for up to 140C and of the MT33 are good for up to 120C.

    It is hard to tell to what temperature this bearing can heat-up in the 348. I bought the MT33 for spare (original still good) with assumption that the temperature of this bearing will not exceed 120C (tracking/racing the car excluded).

    Perhaps you can check with SKF whether they can supply 3208A-2RS2 TN9/C3 VT113.
     
  23. 348Jeff

    348Jeff Formula 3

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    #23 348Jeff, Sep 1, 2022
    Had another reply - the good news is that they are not discontinued - just a worldwide shortage! :-(


     
  24. Ferrarium

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    #24 Ferrarium, Sep 1, 2022
    I bought a new one in the box last spring, just had to search hard. Same exact part number stamped on both.
     
  25. 348Jeff

    348Jeff Formula 3

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    #25 348Jeff, Sep 2, 2022
    I actually emailed SKF direct this morning and got the following reply:

    Saying that though...the email arrived moments after I had just place an order for a bearing with FerrariParts. I did enquire with them and its an NSK bearing so they agreed to match EuroSpares price of £104.71 + VAT.
     
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