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  1. #1
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    DUC 32 damper knob/damper rod bolt turning

    Hi guys, (Ethan)I just replaced the oil in the damper and recharged to 65psi. When I reinstalled the damper cartridge and threaded the damper bolt onto the damper rod I noticed that there is up and down play of the whole lower leg on the upper a tube. The bolt does to seat all the way onto the top cup. Once I installed the lock out and rebound knobs (properly) they just keep turning and the damper bolt and rod turns with them. I noticed about a 1 to 2 mm up and down play of the knobs on the upper tube top cap.
    Now when I try to disassemble the damper rod bolt and rod, they turn together and the bolt does not loosen (no resistance, it just keeps turning in either direction) so I can pull the damper cartridge out of the upper tube.

    Any Ideas how I can unthread the bolt so I can pull out the lower leg?

    When I had it apart I noticed that the damper base cap (where the schrader valve attaches) was loose and were able to turn by hand. Does this need to be tight to create a tight seal for the oil/air charge?

    As I mentioned above I first need the get the damper bolt unthreaded.

    Thanks

  2. #2
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    My little cordless drill has an impact mode. You may have to put some resistance on the drive so it will impact and not just turn continuously.

    You could also try to hammer the end of your wrench with a rubber mallet to make your own impact.

    I have had this happen to me a couple of times. I haven't figured it out yet.

  3. #3
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    I am not sure what you mean. The bolt and rod (the bolt threads into the rod) turn together. I tried turning by loading/compressing the fork while on the wheel so the upper end of the rod compresses up against the upper tube but no luck. I also tried while pulling the leg out so the head of the bolt is seated onto the upper cup. No luck.

    In regards to why this happening: Either the bolt has not threaded into the rod enough to secure it into the rod (I am not sure how this can be done as they turn together) or the rod is longer then it should be due to internal o-ring damage. Either way i need to unthread the bolt first.

  4. #4
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    Geweber, I did mail you the rear damper on Wed morning so you should have it soon.

  5. #5
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    Thanks for the status on mailing the damper.

    If you give a quick hammer blow to your wrench then the bolt may turn out of the damper tube.

    The other thing you might try is to unscrew the seal head. I just put a 30mm 6 point socket on mine but it didn't come loose. I would guess it has lock tight on it.

    The top of the damper rod has teeth in it. I just took mine off and some of these are worn down. In the second picture you can see some of the teeth are worn down.
    Attached Thumbnails Attached Thumbnails DUC 32  damper knob/damper rod  bolt turning-top-damper-rod-duc32.jpg  

    DUC 32  damper knob/damper rod  bolt turning-top-damper-rod-showing-worn-teeth-duc32.jpg  

    DUC 32  damper knob/damper rod  bolt turning-duc32-seal-head-showing-top-damper-rod.jpg  

    DUC 32  damper knob/damper rod  bolt turning-duc32-damper-extention.jpg  


  6. #6
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    Damper rod bolt

    The impact can work well as well as taking the top cap off, but can be tough depending on if locktite was used!
    Once removed, you need find the reason for it not threading in all the way, it can be the damper rod bolt itself getting caught in the rod from an oversized shoulder on the bolt.
    The serrated edges do not "wear" it only needs a bit to "bite" into the bottom of the top cap.
    The base cap can spin, not an issue.
    If i remember "geweber" I'd be suspect. that damper length extension is death, IMO.
    Good Luck-
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  7. #7
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    Thanks, I will give your suggestions a try but it looks that removing the top cup will be the solution.
    Any advice on how to remove it?

  8. #8
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    I would purchase a 30mm socket, if you can find a 6 point, even better, but i bet it will be tough.
    Then take it to a flat grinder, sander or on a lathe take about 1-2mm off the end, this will ensure that the entire socket will touch the top cap since its so shallow. Take the shock of the bike and support on a bench.... be real careful and keep pressure on it. If it doesn't move with a decent force, heat the top area, you can use a lighter if its an anodized fork. (normal righty tighty, lefty loosey!)
    Maverick Suspension Inc.
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  9. #9
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    When I get a DUC36 I will give up on this modified DUC32. It's just that the ride is so much more fun with the full 6 inches of travel both on the ML8 69er and the Niner RIP 9. I guess my RIP is more like a WFO. I am looking forward to riding your niner with a DUC36 if I don't kill myself first.

    140mm+ full suspension AM 29er - what's out there?

    This modification will put more stress on the frame and the fork so I would not reccommend it for a heavy or aggressive rider. I am neither. However, I have started to go faster on downhills due to the performance of this fork. It may be a pilot error that does me in.
    Last edited by geweber; 01-09-2012 at 05:45 AM.

  10. #10
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    I got the 6 point 30mm socket ( automotive shop) now the hard part of grinding it down smooth and level.
    I wish I had a lathe. I will give the impact driver a shot first.
    Thanks for your help

  11. #11
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    I managed to get it out with the impact drill. I am happy I didn't have to try to remove the top cup.
    I think the cause might have been the teflon tape on the threads. I cleaned the threads and the bolt threaded smoothly into the rod. I will now reassemble the fork.
    Thanks for your help!

  12. #12
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    Glad you got the impact wrench to work.

    Would it work to put an O ring on this nut to seal the oil. I don't worry about it since I don't put the fork upside down often. A thin soft washer under the flat part of the nut might work better. I assume the oil comes through the teeth at the top of the damper rod and comes out under the flat part of the nut.

    Ethan, if the nut doesn't tighten fully and you continue to turn it would that not wear the teeth down or cause them to dig into the top cap? What happens if this nut comes loose a little bit and you ride with it for awhile?

  13. #13
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    do not use an o-ring, the bolt needs to be solid against the top cap.
    use a few wraps of Teflon tape, mostly on the bolt head shoulder, where it will touch both the top cap and underside of the bolt. this is only needed on older forks without o-rings in the top cap to seal the shaft. you can use a thin copper washer, but then you need to turn the top of the bolt down so it go back to the original stack height. the shaft is hard anodized, you'll not wear it out! if the bolt loosens it will just knock and the knobs will not stop properly.
    45 in/lb MAX on the bolt (light torque)
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