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jack hammer!!, post solid mass conversion effect??

Discussion in 'A3/S3/Sportback (8P Chassis)' started by davidashaigh, Jul 23, 2011.

  1. davidashaigh
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    davidashaigh New Member

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    Hello alll.


    i have recently converted my DM flywheel to a solid variety. mainly because it is susggested that this is the best ting to do when the DM breaks down. since i have had it back it had been making a jack hammer kind of noise, my mechanic says he is unsure as what it can be. had the usual parts replaced with the solid mass (clutch plate, bearing etc.) the noise is only there when the car is ideling, at lights etc but also when not in gear at slow speeds. it does go away when i apply the clutch though.

    has this happened to any of you and what could be the cause??

    cheers guys, Dave

    55/a3/1.9tdisport
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  2. akash_sky1
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    akash_sky1 Active Member

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    Brave move fitting a SMF to a 1.9TDI! Your mechanic should have warned you of the vastly increased NVH that comes with an SMF. The single piece nature and lower mass means the new flywheel is transmitting a lot more vibration to the rest of the drivetrain/ car, and this is at its most noticeable when idling. This is probably what your hearing as you say mainly at idle and coasting at low speeds unless the clutch is not engaged, ie not touching the new flywheel
    Last edited: Jul 23, 2011
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  3. Adam.
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    Adam. Meow.

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    I had a smf on my old golf 110 tdi.

    You do get a bit of clutch chatter but it waas so much better to drive.

    Sounds normal to me!
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  4. S3Alex
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    S3Alex Rarely neutral

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    I'm surprised your mechanic has no idea why it's doing this.

    It's simple mechanics,even to a mechanical moron like myself.....the purpose of a DMF is to damp and reduce vibrations of this sort,and it's a tuned mass damping system.

    Remove it,and all of the NVH it was damping out is free to pass through.
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  5. devonmikeyboy
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    devonmikeyboy As far from JBS as possible !

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    Sounds like your "mechanic" don`t know ****e about mechanics to me. He obviously doesn`t have a clue how a DMF works or fitted to modern diesel cars. Fitting a SMF to anything other then a highly tuned diesel car is NOT the best thing to do when the DMF dies.
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