MK3 Top mounts on Monotube Bilstien (B8)

Discussion in 'Chassis' started by NateS2, Mar 28, 2020.

  1. NateS2

    NateS2 Paid Member Paid Member

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    So I've currently got a build thread for my MK2, and I'm going to be fitting a Bilstein B12 suspension Kit. I've made this thread to compare the MK3 top mounts to MK2 G60 items, and to mention some things about how each of the designs fit.

    Issue 1
    First thing is the that the MK3 mounts (Left) have a tilted spring plate when compared to the G60 mounts (right). I'm not sure if this is something to with MK3 springs have lateral force compensation? Could someone confirm? @Finite mentioned this in one of his threads
    [​IMG]

    Issue 2
    The G60 mounts work how I'd expect. You can hold the rubber mount still and freely spin the shock body. The castle nut/bush which holds the mount together runs on the bearing inside the mount. This means that the piston and body can turn together.

    In contrast, the MK3 mounts don't work as I'd expect. The image below shows the top of the B8 strut[​IMG]
    When the bearing and plate fitted it looks like this. Note the small gap between the plate and bearing, this would be taken up by the spring pressure:
    [​IMG]
    When you tighten the threaded bush, the bearing is clamped against the base of the threaded section of the shock. This means that even though the spring plate can rotate on the bearing, if you were to rotate the shock body, the piston would have to spin inside the shock as it is clamped to rubber by the threaded bush and bearing. This doesn't seem right because surely its better for the shock seals if the piston isn't twisting?

    Is this how its meant to work? Or is there something wrong with my setup?
     
    Last edited: Apr 29, 2020
  2. blu-tak Forum Member

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    Did you get an answer in the end?
     
  3. NateS2

    NateS2 Paid Member Paid Member

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    Not really, got a wishy washy answer from German technical support. Other manufacturers and later VW’s work like the MK2 G60 mounts, which makes way more sense to me. If you’ve got the bearing there you might as well use it to totally isolate the piston, rather than forcing it to turn like the MK4 ones do. If I makes any difference? Who knows, but I like the idea of the MK2 one better.

    I also rang UK customer “argument” about why I had been given a mixture stainless and zinc plated nuts in a suspension set. Was told that it was impossible even though they had pictures of my set which clearly had one slightly rusty zinc plated nut and one stainless nut stamped “A2”. I also showed the weight difference and the fact one is magnetic, but was told no, “you’re wrong”. Bit of a joke really
     
  4. blu-tak Forum Member

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    I still run stock mk2 topmounts ok, let alone G60, but plenty of people run the mk3/vr6 setup there must be someone that can comment.
    I imagine its not a bilstein specific issue, but a mk3 topmount compatibility issue...?
     
  5. Tristan

    Tristan Paid Member Paid Member

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    For the amount of rotation they do, relative to vertical motion, I can't see it being an issue.
     
  6. NateS2

    NateS2 Paid Member Paid Member

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    On a MK4 it would be the same, it’s just how they’re designed. As Tristan says I doubt it’s an issue, I just wonder why they changed it
     
    Tristan likes this.

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