Preventing rattle on shorter springs

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Lago Blue
    S2Forum Maniac
    • Jul 2009
    • 843
    • Country: Canada

    #16
    Here are a few not to...

    Adam,

    Whether they're good enough is up to you. That you may already have your doubts is perhaps evidenced by your question.

    a) Consider that there are likely good technical and legal reasons that say Bilstein for instance, offer a damper which accommodates shorter springs;

    b) A possibility, with your current set-up, during an occasion when having the suspension suddenly go "solid" could be harmful, you may already be into the bump-stops; exactly when you need to have some free-travel remaining to avoid that harm. A suddenly too "solid" single corner of the car could cause a slide;

    c) The MoT guy may still not approve;

    d) It (clamping) immediately points out that incorrectly matched components have been cobbled together, often but perhaps politically incorrectly called "ghetto";

    e) The accident investigator/insurance co. may not like it;

    f) Does any car, any where, come OEM equipped with hose clamps so employed?

    g) The top perch's circular ramp is indexed to the spring end and needs to be kept that way, the correct spring's length provides the pressure that does that quite reliably; a hose clamp cannot. Would you're upper perch clamp interfere with strut rotation for steering?

    h) Note the bottom perch's factory tab which locates the end of the spring, but does not attempt to totally fix that end in place either laterally or vertically. There are reasons for that;

    i) This spring/lower perch interface is the exact source location for noise in complaints often voiced by B2/3/4 owners, particularly when non-OEM parts are employed (think low-speed "Twang"). That noise is the result of spring movement which must be accommodated;

    j) If you've ever had the spring and lower perch apart, you might recall seeing the wipe pattern made by the pig-tail of the spring into the paint and steel of the perch, the result of the spring squirming and moving about during normal suspension travel. There are large forces at work here; and a hose clamp simply isn't up to it;

    k) The spring moves in part because the spring's geometric and effective centers are not co-incident, and it must be allowed to move. This is why the perches are so generously sized, simply cupped or coned; and not "clamping" the spring at one small single place. So even after picking a spot on the perch to clamp it, if it could be done with something more suitable, such clamping would have to allow for the movement at that location, i.e. be loose enough; and therefore likely very effective at taking the paint off in this high-stress location, hastening spring failure;

    l) Particularly here where the intent of the mod is permanent, it's execution should not look like something you would do just to "get home" after breaking a spring while away.

    m) Are you certain you'll keep your alignment settings beyond the next trip on a hoist?

    n) Perhaps this is an example of why the best done mods are incorporated invisibly. They ought to be done seamlessly using both OEM and hot-rodding's empirical techniques.

    o) Consider the why of your trying to do this mod now. What are you trying to achieve/improve? The key to a mod is in it's proper execution. Does this get you there? Currently, wouldn't the car work better with some stock height springs?

    p) Also consider that lowering a car has a certain reputation. Don't prove it.
    Last edited by Lago Blue; 6 April 2017, 14:47. Reason: punctuation, read-ability, clarity

    Comment

    • Fat Audi 80
      Super Moderator
      • Jan 2004
      • 10547
      • Country: England

      #17
      Back in the day I used some large cable ties to hold the springs in position whilst under full droop. It passed the MOT, and as others have said, when was the last time a car used the full upward travel of the suspension during normal driving?
      The Perfectionist
      sigpic
      Audi Class Concours winner Stoner Park 2014, ADI Concours D'Elegance Class Winner 2008, Runner up 2014. Winner, S2Forum Show'n'Shine Billing 2006 & 2008.

      Comment

      • John.
        S2Forum Fiend
        • May 2012
        • 2615
        • Country: Scotland

        #18
        More coffee?........anyone?!

        Comment

        • adam g
          S2Forum Addict
          • Feb 2007
          • 445
          • Country: United Kingdom

          #19
          Originally posted by Lago Blue
          Adam,

          Whether they're good enough is up to you. That you may already have your doubts is perhaps evidenced by your question.

          a) Consider that there are likely good technical and legal reasons that say Bilstein for instance, offer a damper which accommodates shorter springs;

          b) A possibility, with your current set-up, during an occasion when having the suspension suddenly go "solid" could be harmful, you may already be into the bump-stops; exactly when you need to have some free-travel remaining to avoid that harm. A suddenly too "solid" single corner of the car could cause a slide;

          c) The MoT guy may still not approve;

          d) It (clamping) immediately points out that incorrectly matched components have been cobbled together, often but perhaps politically incorrectly called "ghetto";

          e) The accident investigator/insurance co. may not like it;

          f) Does any car, any where, come OEM equipped with hose clamps so employed?

          g) The top perch's circular ramp is indexed to the spring end and needs to be kept that way, the correct spring's length provides the pressure that does that quite reliably; a hose clamp cannot. Would you're upper perch clamp interfere with strut rotation for steering?

          h) Note the bottom perch's factory tab which locates the end of the spring, but does not attempt to totally fix that end in place either laterally or vertically. There are reasons for that;

          i) This spring/lower perch interface is the exact source location for noise in complaints often voiced by B2/3/4 owners, particularly when non-OEM parts are employed (think low-speed "Twang"). That noise is the result of spring movement which must be accommodated;

          j) If you've ever had the spring and lower perch apart, you might recall seeing the wipe pattern made by the pig-tail of the spring into the paint and steel of the perch, the result of the spring squirming and moving about during normal suspension travel. There are large forces at work here; and a hose clamp simply isn't up to it;

          k) The spring moves in part because the spring's geometric and effective centers are not co-incident, and it must be allowed to move. This is why the perches are so generously sized, simply cupped or coned; and not "clamping" the spring at one small single place. So even after picking a spot on the perch to clamp it, if it could be done with something more suitable, such clamping would have to allow for the movement at that location, i.e. be loose enough; and therefore likely very effective at taking the paint off in this high-stress location, hastening spring failure;

          l) Particularly here where the intent of the mod is permanent, it's execution should not look like something you would do just to "get home" after breaking a spring while away.

          m) Are you certain you'll keep your alignment settings beyond the next trip on a hoist?

          n) Perhaps this is an example of why the best done mods are incorporated invisibly. They ought to be done seamlessly using both OEM and hot-rodding's empirical techniques.

          o) Consider the why of your trying to do this mod now. What are you trying to achieve/improve? The key to a mod is in it's proper execution. Does this get you there? Currently, wouldn't the car work better with some stock height springs?

          p) Also consider that lowering a car has a certain reputation. Don't prove it.
          You raise some interesting questions Lago Blue, and thanks for taking the time to do so. As you say, I already had my doubts, more research on the net shows no one outside the off road community (who actually go off road), use spring clamps. There are people on every car forum out there with my issue and no examples of people clamping springs to perches - so probably for good reason.

          Just to put your mind at rest on the last point, I'm not lowering the car, these are stiffer springs for standard ride height so are slightly shorter when unladen.

          I'm still not convinced springs are supposed to move, otherwise why would OEMs use locators at all, perhaps they don't bother fixing them down as the compression is designed to be sufficient to stop movement and an any thing extra would be wasted money.

          Anyway, as my target is improved handling and I'm fitting new springs, mounts and bushes I've decided against the risk of introducing an unknown feature. So, despite protests from my wallet I've order some bilstein B6s to do the job properly.

          Sent from my D5803 using Tapatalk

          Comment

          • Lago Blue
            S2Forum Maniac
            • Jul 2009
            • 843
            • Country: Canada

            #20
            Possible next steps...

            Your quite welcome sir. These kinds of discussions are exactly what the forum is for. I do find the mental exercise of visualizing how components behave together quite interesting.

            Re possible spring movement (i.e. squirming), please see the C-shaped "footprint" in the metal of the lower spring perch photo. This is Mance (Mr. Pro-Mounts) Etheridge's picture. Without his authorship I don't think I ever would have looked twice at this.

            Theoretically, despite the OEM contouring of the lower perch, there may be as few as only three points of contact between the spring and perch, or as many as to make an infinitely thin line. However, without the said movement there would be no visible wiped footprint as shown, widest where the spring flexes sideways most, and interestingly not necessarily right at the end of the coil. Note the wider scraped path in the foreground. The small vertical factory tab on the lower spring perch purposely only serves to prevent axial rotation between the spring and lower perch.

            Four points I wanted to mention, the first is a question, the second a suggestion, the last two are requests:

            a) If you use B6s (aka HDs) and not B8s (aka Sports) with your springs of shorter free length, might you not still have the same current "capture" issue, or are you going to use other "new springs" of regular length?

            b) Please do the drain-hole mod to your strut-housing bases to preclude the slightly mis-named "Frozen Strut Syndrome" from occurring. This is strictly a yellow Bilstein damper failure prevention mod, particularly useful outside North America, where you do not enjoy the life-time warranty I do here.

            c) As you're replacing these anyhow, please also consider incorporating the following two strictly add-on type mod items which (I humbly manufacture, and) serve to both reinforce and preserve for years, the OEM top-mounts and A-arm bushes:

            i) "Stops" to buttress strictly brand new Audi Boge/Sachs A-arm bushing function; &

            ii) "Ersatz-Savers" An insert for strictly brand new examples of the latest Audi Boge/Sachs top-mount, which aims to maintain the host mount's "as new" height, function and life-span; indefinitely.

            Although they differ greatly in material and operation, both stops & savers serve to limit the axial travel between the shell and core of each subject bush and mount, while still allowing the OEM part's "soft" function, each is strengthened and restrained, which garners improvements including host reliability and tactile steering response.

            I'll come back and make the links later today. Done.
            Last edited by Lago Blue; 10 April 2017, 01:41.

            Comment

            • Bowie69
              S2Forum Fiend
              • Nov 2013
              • 2675
              • Country: England

              #21
              I'm not suggesting that they are a perfect solution for you, but the first link from a Google search produced this:

              http://forums.lr4x4.com/topic/76957-...s-popping-out/

              Comment

              • adam g
                S2Forum Addict
                • Feb 2007
                • 445
                • Country: United Kingdom

                #22
                Originally posted by Bowie69
                I'm not suggesting that they are a perfect solution for you, but the first link from a Google search produced this:

                http://forums.lr4x4.com/topic/76957-...s-popping-out/
                Thanks for the link, Ive now decided I don't want to be the guinea pig for trialing this solution on a UR quattro, I dont have a lot of spare time on my hands these days so want a fit and forget solution ideally.

                Comment

                • adam g
                  S2Forum Addict
                  • Feb 2007
                  • 445
                  • Country: United Kingdom

                  #23
                  Originally posted by Lago Blue
                  Your quite welcome sir. These kinds of discussions are exactly what the forum is for. I do find the mental exercise of visualizing how components behave together quite interesting.

                  Re possible spring movement (i.e. squirming), please see the C-shaped "footprint" in the metal of the lower spring perch photo. This is Mance (Mr. Pro-Mounts) Etheridge's picture. Without his authorship I don't think I ever would have looked twice at this.

                  .
                  I cant check my own struts for the footprint as I have had them blasted and painted.

                  The springs I am using have been fitted by quite a few UR owners, there was a group buy on the quattroforum for them. The only people that had the issue with loose springs were those with Koni shocks, the reason being they have 20mm longer travel than OEM shocks, hence those with Bilsteins or OEM shocks had no issue.

                  Bilstein dont do B8s for the UR so B6 is the only sport option but my research suggests these will work.

                  Thanks for the tip on the the drain hole, I haven't heard of it before but it sound self explanatory (drill a hole in the bottom of the strut prior to dropping the shock in?).

                  I look forward to the links for the parts you suggest fitting as I am struggling to imagine what the look like and where they fit. Will your Ersatz savers work with heavy duty Meyle top mounts as this is what I have purchased.
                  Last edited by adam g; 11 April 2017, 19:20.

                  Comment

                  • newsh
                    S2Forum Obsessed
                    • Aug 2003
                    • 16226
                    • Country: United Kingdom

                    #24
                    I've just been watching a few YouTube videos of Koni shock rebuilding. They look really easy to work on. You could probably fit a spacer to the rod to restrict travel.

                    S2 Coupe 3B Project


                    Ur quattro restoration

                    S2 Avant

                    Boost is the new rock and roll!
                    sigpic

                    Comment

                    • Bowie69
                      S2Forum Fiend
                      • Nov 2013
                      • 2675
                      • Country: England

                      #25
                      Aware you've probably got yourself a solution, but now in front of a proper computer rather than my phone, here are a couple of standard fitment items from a coild sprung Land Rover:

                      Rear spring retainer:
                      Order your Spring Retainer Plate - NRC4318 - Genuine ⛽ Low prices and fast, worldwide delivery ✈ British car experts ♚ Call ☎ 01522 568000 or ☎ 1-855-746-2767


                      Front spring retainer, where the shock sits inside the spring:
                      Order your Spring Retainer Plate (pair) - NTC6106TFFRT - Terrafirma ⛽ Low prices and fast, worldwide delivery ✈ British car experts ♚ Call ☎ 01522 568000 or ☎ 1-855-746-2767


                      You can buy heavy duty versions each, also. All they do is stop the spring from falling out when the suspension is at maximum articulation. I think the rear ones are maybe 2-2.5mm thick, front a little thicker due to the bend in them.

                      I would suspect if your shock solution didn't work out, a couple of L brackets with a bolt down through the perch would be sufficient. Yes there are plenty of forces happening, but the one are trying to solve is just the up down one, I think? A single point of fixing would allow the spring to rotate as it does now.

                      Comment

                      • Lago Blue
                        S2Forum Maniac
                        • Jul 2009
                        • 843
                        • Country: Canada

                        #26
                        Adam,

                        Re: Drain Hole Mod.
                        Correct, drill a 1/8" hole directly on center in the base of the strut-housing. Theoretically, one could do it with the damper in place, but I haven't done it that way!

                        Re: Yellow Bilstein into B2/3/4 chassis Mac strut.
                        Bilsteins require a little more care to do right. I'm sure there are other tips, but here are some I've used.

                        Re: Ersatz-Savers application:
                        Unfortunately, many owners have written to say they are dissatisfied with either the Meyle HD or 034 mount offerings. Sometimes just "more rubber", like "more cow-bell" is not the music one seeks. If more rubber was going to be a fix, after all the revisions (i.e. part numbers) the Boge/Sachs mounts have been through over the years, they would have done that; but didn't.

                        What the Ersatz-Savers do is try to emulate the success owners had with Mance's brilliant Mount-Savers which are NLA. They will also replace earlier versions of his savers which may require replacement. What the concept shows is that it is less about what is wrong with the latest bona fide factory mount (strictly the most recent dealer supplied Boge/Sachs top-mount for the last and heaviest V6 cars), and more about what is missing from it. In part because this mount has room for a fix that has had some success, and in part because it is (proven by Mance's published testing) a stronger mount than most if not all comers, it is still likely the best starting point.

                        Unfortunately, few old Audi strut top-mount making folks understand how these mounts fail, and there is insufficient room for this fix in "over-filled" mounts such as the Meyle HD etc.
                        Last edited by Lago Blue; 11 April 2017, 15:27.

                        Comment

                        • adam g
                          S2Forum Addict
                          • Feb 2007
                          • 445
                          • Country: United Kingdom

                          #27
                          PM sent ref savers and bushings.

                          Does anyone know a source for OEM Sachs-boge top mounts at a good price. I've been trying audi dealers today but think they must be closed for good Friday. Can't find them online anywhere in UK.

                          Sent from my D5803 using Tapatalk

                          Comment

                          Working...