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348 flywheel

Discussion in '348/355' started by John Glen, Jul 2, 2020.

  1. John Glen

    John Glen Formula Junior

    Dec 30, 2009
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    John Glen Wesanko
    Hello fellow 348 owners. I am presently doing the major maint on my 1990 348ts. I am asking what size and where to source the Torx Plus bit required to remove the flywheel Torx bolts ? Thanks guys, JGW
     
  2. Ferrarium

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  3. yelcab

    yelcab F1 World Champ
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    I don't think it is Torx, although you can take a dremmel tool to a Tork bit to make it work. The edges are more square and they are actually called Ribe bits.
     
  4. Ferrarium

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    Ribe bits are more square like like torx plus. I assumed they were the same. Perhaps not.

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  5. John Glen

    John Glen Formula Junior

    Dec 30, 2009
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    The bolts holding the flywheel together have a head design called Torx Plus. This design is slightly different from the standard torx fasteners in that the pointed "splines" are wider and provide a stronger purchase when applying torque. I believe the bit size is TP-50. That is what I ordered from Amazon, we will see........I'm surprised no one has experience with this ? JGW
     
  6. Koenig1

    Koenig1 Formula Junior
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    Well, here's MD Clutch's video of a 348 flywheel. At point 13:30, Andrew explains the bolts/removal tool(Renault. Great video for anyone wanting to do their flywheel/clutch for a 348/355.
     
  7. yelcab

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    I have and I used a Ribe bit which fits perfectly on the fastener. I did not think it relevant enough to make a post about it.
     
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  8. Ferrarium

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    There are many posts on this actually, including noting its a Ribe bit. Is just so happens none of those folks are on at this time, the search usually works as the posts are out there. Good luck!
     
  9. m.stojanovic

    m.stojanovic Formula 3
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    I ground the peaks of a T-50 bit slightly down to fit the bolts so TP-50 should be the correct bit.
     
  10. John Glen

    John Glen Formula Junior

    Dec 30, 2009
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    Thanks Miroljub, just received the TP-50 bit and it is too big as you mentioned. Guess I'll have to grind it a little.....
     
  11. m.stojanovic

    m.stojanovic Formula 3
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    Upon checking further all these drives, it seems that, for the same number of the bit, the peak-to-peak diameters of the Torx and Torx-Plus bits are the same. I also found info that a Torx bit (having same number as the correct Torx-Plus) can be used on a Torx-Plus bolt head provided that the torque required for the bolt is not close to its upper limit. The diameters across the valleys are obviously different. The Polydrive (Ribe) bits have a different sizing system like M5, M6...M12 etc. so the table below does not apply to them.

    If someone can take a close picture of the flywheel bolt head, we can determine whether it is Torx or Torx-Plus (I don't think it is Ribe). The actual reason why we have to grind the Torx or Torx-Plus, T-50 or TP-50 (50IP) a bit down may be because the bolts require the non-standard T-47 bit (Torx-Plus TP-47 doesn't seem to exist; T-45 or TP-45 are too small). The table I found does not show the diameter of the T-47, just states "GM-style" but it is certainly somewhere in-between T-45 and T-50 (see the measurement of my modified T-50). So, T-47 could be the one we need.

    (Note: The point-to-point diameters I measured on the bits are a bit smaller than what is given in the table, possibly because the table shows the measurements inside the bolt head and the bits are actually somewhat smaller for clearance)
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  12. m.stojanovic

    m.stojanovic Formula 3
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    Just found one of the pictures of my flywheel showing the bolt heads. In poor resolution (zoomed in), it appears to be Torx-Plus. As TP-47 does not exist, it seems that we can either grind the TP-50 down or try the T-47. Or it could be Ribe M8 ? A higher resolution picture will tell.
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  13. Ferrarium

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  14. yelcab

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  15. m.stojanovic

    m.stojanovic Formula 3
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  16. John Glen

    John Glen Formula Junior

    Dec 30, 2009
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    Thanks again Miroljub, hopefully third time lucky. Just ordered the Ribe 8mm bit from Snap-ON. JGW
     
  17. John Glen

    John Glen Formula Junior

    Dec 30, 2009
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    Ordered and just received from Snap-On, tool item# F8RBE which is described as 3/8 in Dr 8mm RIBE bit skt. Fits well and works well. By the way Snap-On has a great online site and is very fast at delivery. Thanks again for all the advice, JGW
     
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