Front top mounts loosening since fitting KW V1

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • coolhand
    S2Forum Enthusiast
    • Apr 2005
    • 163
    • Home: England Current: Australia

    #1

    Front top mounts loosening since fitting KW V1

    I have CompBrake solid spherical top mounts all around which have been without issue for years, recently I had KW V1 installed to my coupe and soon thereafter I noted some knocking and other noises only on the front end.

    A quick peek and I found that the bearings had worked their way loose, first one side, and a day later on the other side, even though they were air-gunned on tight as all heck, and the castle nuts on the top mounts have small locking allen threads to hold them on !

    Searching around the web found numerous owners of KW V1's (fitted to BMW's and other make cars) with EXACTLY the same issues, which at least according to the you tube videos and threads I read, were essentially due to the coil springs binding and thus applying massive amounts of torque to the top mounts when turning the car, the springs can be heard torquing up as they make a 'sprung metal sound !' and after a little driving this leads to the top mounts loosening.

    The V1 don't have upper perches with bearings which would allow freedom from rotation due to the steering position, thus the issue remains not ideally solved without addition of such.. which are found on other better engineered coil-over solutions.

    In the threads I found on the subject, spme were able to solve the issue with the addition of a big washer insterted between the upper coil perch and the bottom of the spherical bearing of the top mount.

    I'm going to pull the whole lot off tomorrow in the presence of my mechanic and see what can be done to resolve this issue, but wanted to ask any S2 Forum users of the KW V1's with solid top mounts whether they had any similar issues and/or found solutions ?

    As I said, this issue is certainly not uncommon according to my trawling of the web, but I've not seen it mentioned on the S2 Forum threads and I searched high and low !!



    Here are a couple of related comments to this issue which I found online:

    "Solution found !
    the perch was loose! There's a little screw that tightens the perch to the thread, and that screw was loose.
    After tightening it, the helper springs stay in place. The buckling sound was from the helper springs moving due to the play in the perch.”



    "Removing the helper spring will help.Its only purpose is to take up slack when the strut is fully extended.
    I would just lose the helper spring. You don't need it. Most kits that have them just have them so they can call themselves TUV certified.
    TUV calls for a helper spring IIRC."
    Last edited by coolhand; 9 February 2017, 09:26.
  • Error404
    Super Moderator
    • Mar 2007
    • 19789
    • Country: United Kingdom

    #2
    My solution:



    Hope that helps
    Panthero Coupé quattro 20vt
    Indigo ABY coupé
    Imola B6 S4 Avant

    Comment

    • coolhand
      S2Forum Enthusiast
      • Apr 2005
      • 163
      • Home: England Current: Australia

      #3
      Mmm... looks like a very well conceived option Alex

      However I have no specific issues with NVH due to the solid CompBrake mounts myself, so I'm wondering if I could similarly implement an additional bearing above the KW perch to allow freedom of rotation of the coils (which appears to be my issue), whilst retaining the spherical bearing in the solid mount.
      Do you think such an arrangement such as this would this be feasible ?

      My mechanic is not available until next week now, so I have more time up my sleeve to consider further possibilities...

      Given that you have obviously tried the solid mounts with KW V1's, do you recall any trouble with the lack of an upper rotational bearing causing the coils to bind when you had them on ?
      Last edited by coolhand; 10 February 2017, 09:49.

      Comment

      • coolhand
        S2Forum Enthusiast
        • Apr 2005
        • 163
        • Home: England Current: Australia

        #4
        Looking further I see a primary stumbling block if I wish to retain the spherical top mounts... there is insufficient thread available on the KW V1 strut to accommodate the addition of a bearing similar to that which you used AND still allow enough thread to attach a securing bolt.

        The images below should make this more obvious.

        My mechanic mentioned that because of this, the only option he could think of if I want to keep the spherical top mounts, would be to instead have a 'bearing mounted lower perch' threaded onto the bottom section of the lower coil where the height adjustment is made.
        Any additional height here could be accommodated by simply dialling the height adjustment as there is plenty of thread to play with there.

        I'm not aware of any bearing mounted lower spring perches to suit, so this could become more of a ball ache that it's worth !

        Also I'm not totally averse to using the poly mount Alex used with the OEM style fitting, but if there are any other suggestions out there which I may have overlooked, I'd like to explore them first.
        Attached Files

        Comment

        • coolhand
          S2Forum Enthusiast
          • Apr 2005
          • 163
          • Home: England Current: Australia

          #5
          Just thinking out loud again

          I may have just sufficient thread to fit the uppermost nut in place, IF I forego fitting of a nut above the upper perch bearing (as shown in the image below taken from Alex's top mount thread).

          Given that the helper springs job is to take up any large suspension displacement when doing Dukes of Hazzard jumps and the like I can't see that it would pose any issue to remove the nut.. but I'm no mechanical engineer... anybody consider this an issue ?

          I will however still need to add a washer in order to provide sufficient clearance such that the spherical bearing can continue to function as intended.
          Attached Files
          Last edited by coolhand; 10 February 2017, 11:06.

          Comment

          • quattrostyle
            S2Forum Zealot
            • Oct 2006
            • 6229
            • Country: Netherlands

            #6
            Subscribed what bearings did you get for those?

            Comment

            • Error404
              Super Moderator
              • Mar 2007
              • 19789
              • Country: United Kingdom

              #7
              Hi Luc,

              OK first off, those Compbrake top mounts are really well known for coming loose so I doubt its an issue with the KWs. Is it the top ring coming loose, or the sleeve nut coming loose?

              Second, I wouldn't use those bearings directly on the composite KW spring retainers as the bearing face is tiny and I'd be worried it will damage the spring retainer. Fit a thick washer between the bearings & the spring retainer.

              I don't think you could fit the OEM Cupra bearing under those solid mounts but if you waat to try they are not expensive, P/n is 1J0412249

              FWIW the poly mounts I modded and fitted with the KWs feel just as tight as the solid mounts, with none of the harshness

              HTH
              Panthero Coupé quattro 20vt
              Indigo ABY coupé
              Imola B6 S4 Avant

              Comment

              • coolhand
                S2Forum Enthusiast
                • Apr 2005
                • 163
                • Home: England Current: Australia

                #8
                I've fortunately not had any issues with the CompBrake mounts coming loose whilst running factory suspension over several years, but it is apparent that the large castle nut is a half assed idea.. their adjustable castor/camber mounts use a much better locking system like that used on the AKMotorsports and 2Bennett mounts, which has 5 or 6 allen head bolts in a cap.

                At different times since fitting the KW's I actually found both nuts loosened (the strut nuts need to be swapped for nylock types) so the car has been parked up whilst I find a solution.

                Yes, it makes sense not to use the bearing directly on top of the composite spring retainers.

                I can't say I've noticed any more harshness with the solid mounts (then again I run solid sub frame mounts and tubular control arms with spherical bearings front and rear, so the only rubber between me and the road is 40 profile tyres )

                Having said that, I don't doubt that the poly mounts are more compliant and as I'm going to get the Cupra bearings anyway I may as well ask if you have a part number for the mounts too ? I've got nothing to lose at this rate

                Comment

                Working...