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Question about wheel hubs

Discussion in '308/328' started by Dave Bertrand, Apr 7, 2021.

  1. Dave Bertrand

    Dave Bertrand Karting
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    Dec 24, 2005
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    Each of my wheel hubs have two little teats sticking out of the surface that the wheel mounts to. What are they for? Sorry I forgot to snap a pic.
     
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  3. absostone

    absostone F1 Veteran
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    Teats? probably the small posts that hold the wheel from falling off before the lugs are positioned
     
  4. 4right

    4right Formula 3
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    I always thoughts those were hangers to hang the wheel from while installing the wheel bolts.
     
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  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Main function is to keep the lubgbolt thru holes in the brake disc aligned with the lugbolt threaded holes in the hub (as you install the wheels). Also, keeps the brake disc mounting surface in intimate contact with the hub surface (so no debris falls in between the two surfaces when the lugbolts are removed, gets trapped, and results in "wobble" of the brake disc).
     
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  6. Dave Bertrand

    Dave Bertrand Karting
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    Thanks. That makes sense, but why do they need to protrude like that? The Porsche 911 uses simple Philips head machine screws to perform the same thing, and they are flush to the surface. So what I'm really asking is, what's the purpose of having those posts stick out like that? There's nothing on the wheel centers that accommodate those posts that I can see.

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  8. Dave Bertrand

    Dave Bertrand Karting
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    There's a special wheel-hanger tool for that so I doubt it. Plus, they don't appear to contact the wheel at all when it's mounted.
     
  9. absostone

    absostone F1 Veteran
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    your pic is what i was talking about
     
  10. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    That's true, but they aid in aligning the lugbolt holes in the wheel with lugbolt holes in the rotor/hub when installing the wheel. Also, by sticking out more than the hub center, they help prevent the wheel from falling off during installation (before getting the first lugbolt installed).

    There are features on stock wheels -- note the blind holes on the backside on this stock 14" wheel meant to engage those pins:
     

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  11. Mule

    Mule F1 Rookie
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  13. Dave Bertrand

    Dave Bertrand Karting
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    The 16" 328 wheels don't have any locating holes like that. Maybe the feature is a leftover from an earlier model. It just seems like such a klugey solution when they could have simply provided a screw-in wheel hanger like the $20 one we can buy, which is easier and simpler to use. I can see how people may have been using those pins this way for 30+ years, but I still wonder if this was really Ferrari's intended use for them.

    Do the 308, Dino 246 and/or Mondial have these too?
     
  14. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Looks like they used the 104368 pin at the front and 104370 pin at the rear on earlier models, but then went to using the 104370 pin at both the front and rear on 328 and later models

    https://www.ferrariparts.co.uk/part/ferrari/104368

    https://www.ferrariparts.co.uk/part/ferrari/104370

    (I believe because the thicker brake rotor at the front on 308 vs the rear rotor -- same reason the front lugbolts are longer than the rear lugbolts on 308. Then they got smarter ;), and made the front and rear lugbolts the same length so the same locating pin could be used at front and rear.)

    You seem to be having a lot of heartburn over this? You still need something to keep the brake rotor well clamped onto the hub when the wheels are off -- like you noted on Porsche -- just ignore the protruding portion or cut it off ;).
     
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  15. Dave Bertrand

    Dave Bertrand Karting
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    Dec 24, 2005
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    Thanks Steve, I don't know why I didn't think to check the description in the parts diagram. "Stud for wheel alignment" - that's pretty clear. And of course there needs to be a way to secure the brake disc to the hub, as you pointed out earlier. Whew, glad that's over. NOW I can finally get some sleep. :D
     

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