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Clutch Question

Discussion in 'Boxers/TR/M' started by c4b4the04, Jun 9, 2020.

  1. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    147
    Northern Virginia
    Full Name:
    Cassidy
    Good afternoon all, I could really use some help.

    Watching Jamie's clutch issue spurred me to re- check my own assembly as I am still mid-build at the moment. Some of you may be following my repair to an 88 car that lost a tooth off first gear in February. This has mostly been on me in a very small garage.

    Here's the question:
    New clutch kit from Eurospares, flywheel was stripped to bare plate (no studs) and trued on a flywheel grinder (not a lathe)

    I currently do not have ANY spacers in the clutch. Here is what I see from the manual:

    B= A+X+C+D
    X= B-(A+C+D)

    So here are my numbers
    A (Ring thickness- this is my original spacer ring) 15.79mm
    B (plate package thickness) 26.55
    C (distance from pressure plate surface to mounting surface) 6.86
    D (book defines preload value, expressed as 3,5 division sign 3,8: I interpret that to mean 3.65 as the middle)

    With those numbers:
    X=26.55- (15.79+6.86+3.65)
    That would give me X= .25

    B= A+X+C+D would then give me

    26.55 = (15.80+.25+6.86+3.65), or 26.55=26.56

    So my initial assembly, I did not need any spacers. This was my math a month ago. Is this not right? I would need a .25mm spacer, but that is insanely small, .009 of an inch? The first time you drive the car you are likely to burn more than that off of the clutch discs.

    Really could use some advice here. I really didn't think it needed any spacers, using that logic from the book. I will post an image below from my phone with the manual procedure and the clutch currently. I could sure use some help on this step. Thank you gentlemen...

    Cassidy
     
  2. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    147
    Northern Virginia
    Full Name:
    Cassidy
    Current clutch config and the WSM procedure
     

    Attached Files:

  3. PA32Pilot

    PA32Pilot Formula Junior
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    Mar 5, 2020
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    Jamie Kirk
    Have you mounted it and treid rotating it like Turbo-Joe had me doing last night?

    I have been chasing thousandths of an inch on this car for a month and I can say yes it does matter. I used a .010 thinner spacer (just so happen to have washers in my airplane nuts and bolts pile that fit!) and this is the difference in pressure.

    Before:


    After:
     
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  4. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    when you measure that you need no spacers than the clutch discs are down or the intermediate ring is too thin, so worn out
     
  5. PA32Pilot

    PA32Pilot Formula Junior
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    I used feeler gauges to set spacing and do the turn test. You will start to see a slight increase or decrease in rotating friction. Make sure your initial measuring is done with no spacers.
     
  6. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    147
    Northern Virginia
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    Cassidy
    I'm so glad to hear from you both on this topic..... but I have to understand. What is worn out? The clutch discs are brand new and so is the pressure plate. What would be worn out?

    I'll go watch those videos. I get chasing thousandths in a diff, not in a clutch that will wear the very first time you let it out....sigh....thought I had this one finished up.

    Cassidy
     
  7. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
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    Cassidy


    This is what it looks like currently, really looking forward to your thoughts.
     
  8. Veedub00

    Veedub00 F1 Rookie
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    Jun 30, 2006
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    I thought spacers were for the pressure plate to be seated at the right amount of preload.
     
  9. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    147
    Northern Virginia
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    Cassidy
    The clutch kit came with 6 washers, I assumed they were for the outside of the pressure plate. Is that not the case? I guess that would make sense why they were ziptied to the spring steel arms. Fortunately I haven't started anything up and the cradle is still out of the car.
     
  10. PA32Pilot

    PA32Pilot Formula Junior
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    This looks close to what mine is. Remember I put the spacers on wrong for 3 of them.
     
  11. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
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    Cassidy
    Jamie do you have 5 minutes for a phone call?
     
  12. PA32Pilot

    PA32Pilot Formula Junior
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    In a depo right now, can I call ya when I'm done? Shoot me a text
     
  13. pshoejberg

    pshoejberg Formula 3
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    The spacer are there to prolong the lifespan of the clutch plates. When the plates wear down the spacers can be removed. No need for for tenth of millimetres thinking here. And the spacers are needed when the components are new and can be removed when the components are half worn down. See snip from 512 bb workshop manual below. I assume the Testarossa equals this principle?

    Best Peter

    Image Unavailable, Please Login
     
  14. Veedub00

    Veedub00 F1 Rookie
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    my 6 spacers are about twice as thick as a regular washer.
     
  15. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    you may tighten the intermediate plate with 3 8 mm nuts and put some washers under, the thread of the bolt is not long enough
    just now you not did this and even the disc turns not free. so I think when you tight the intermediate disc that then you cannot turn the clutch disc anymore

    not only. they are also for the free turn of the front clutch disc important
     
  16. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    147
    Northern Virginia
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    Cassidy
    Great talking with Jamie verified that I have the parts in the right order. My problem seems to be the intermediate plate doesn’t stay snapped onto the 3 studs like the old one did. I get now where the washers need to go. If the clutch kit came with the washers, can I assume they are the right size?


    Sent from my iPhone using FerrariChat.com mobile app
     
  17. turbo-joe

    turbo-joe F1 Veteran

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    good question, today I only can say: don´t trust anything and double check all when you get some new things
     
  18. Veedub00

    Veedub00 F1 Rookie
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    there's very tiny circlips on the intermediate plate. under the spring holes
     
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  19. Veedub00

    Veedub00 F1 Rookie
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    press them in until they click into place.
     
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  20. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
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    Northern Virginia
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    Cassidy
    Mine don't click on like the old intermediate plate did...I see what you are saying, they just don't stay on that way. As soon as you put the second clutch disc on and the pressure plate, then they look normal. I am not sure why these clips don't stay like the old one did, I didn't damage those screw in studs in any way.

    I redid my math, so instead of D = a range of 3,5 to 3,8, I divided as per the book, and got the number . .921

    Then, when I do the math, says the shims should be 2.98. My shims that shipped with the clutch are 2.37, so I am off .61mm. Do I need to go cut some .61mm thicker spacers or do you let that fly? I just can't envision that small amount making a difference on a clutch binding, when the system wears down you are supposed to remove the spacers entirely.

    I am really stumped. Going back to doing cam timing...you know, the easy stuff... geesh.

    Thanks for any input on the shim size.
     
  21. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
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    Northern Virginia
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    Cassidy
  22. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    yes, if you have the right thickness
     
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  23. PA32Pilot

    PA32Pilot Formula Junior
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    c4b4the04 likes this.
  24. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    147
    Northern Virginia
    Full Name:
    Cassidy
    So the car is back together now and the clutch is not disengaging fully. Bled the clutch several times but you can hear an audible ‘click’ when you push the clutch in.

    When I was installing the intermediate plate (spacers on correct side) the ‘retainer clips’ just slip over my studs and don’t stay on. I think the issue is the intermediate plate is releasing the front disc and then binding up the rear one. Strange indeed.

    Anyone heard of this? I’ll try to get a video of it but the intermediate plate just seems to move too far back when the clutch is in


    Sent from my iPhone using FerrariChat.com mobile app
     
  25. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    147
    Northern Virginia
    Full Name:
    Cassidy

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