Cam bolts stripping.

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Hair, Apr 6, 2008.

  1. uk_mouse

    uk_mouse Aquatic adventurer

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    It does, but in this application I thi nk you'd be hard pressed to get the bolts in without getting some engine oil on them. When I've removed my cam bridges I always put a light coating of engine oil on the bolt threads before reinstallation, and it doesn't seem to have done any harm yet!

    I'd be wary about putting anti-seize on a bolt that's inside the engine, although I admit it's unlikely to do any harm.
    #21
  2. jsrider

    jsrider Long timer

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    FWIW the cylinder head nut TSB from KTM recommended using anti-seize. Two of the cylinder heat bolts are under the valve covers.
    #22
  3. emelgee

    emelgee Been here awhile

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    As far as I recall the BMW issue was related to rear wheel nuts. There were a couple of instances in the UK of wheels coming loose while the bike was being ridden:huh
    I don't remember if this was caused by the bolts coming loose due to the anti-sieze, or if lubricating the threads caused them to be overtightened and then shearing...
    As far as cam bolts are concerned I just put a drop of engine oil on the thread - no problems with them coming loose, or siezing in place.
    #23
  4. Stephen

    Stephen Long timer

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    We measure torque as an analog of fastener stretch. We want to stretch the fastener sufficiently to ensure a certain level of tightness of the fastened parts. Anything like thread friction increases the perceived tightness of the fastener without increasing the tightness of the joint. In other words, we want it all slick as snot so the torque wrench only measures stretch.

    The cone washers, actually. Any tapers, generally, go unlubed. I've seen folks split auto brake hubs...

    And yeah, I can't imagine that the cam bridge bolts could be dry. They were certainly oily by the time I got'em out, and I'm sure I can't replace them with getting oil on'em. But it sure felt like galvanic stickiness tryin' to break'em free. Nuthin nuthin nuthin.. bang!

    Anti-seize will prevent reoccurence.
    #24
  5. madrid mark

    madrid mark migrant film worker

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    Good thread. Hair,i hope to see you sat.:ricky
    #25
  6. ceeco

    ceeco two wheels at a time

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    Maybe KTM changed the bolt spec.?? I cant see how this issue would be so random either. Maybe we should ba asking a few more questions.... like year model.

    I'll start by confirming that my and a friends 04' has had the cam bolts removed multiple times w/o issue. We lubed the bolts on install with motor oil and torqued to spec using torque wrench (using steped torquing described in manual).
    #26
  7. HellsAlien

    HellsAlien a has-been that never-was

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    These particular capscrews are a low head height spec. They have about 35/40% less engagement depth in the hex socket vs. a standard height socket head capscrew. This was done because of the tight space reqmts in this head design, for better or worse.
    Suggest always use motor oil to lube the threads, torque to spec (more is not better), and use a bit in new or as-new condition.
    #27
  8. emelgee

    emelgee Been here awhile

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    There's quite a few riders on here who do all their own maintenance work (myself included) and this is the first time this subject has cropped up in the couple of years of been posting here. Sounds like a few isolated instances of overtightening, rather than a general problem.
    #28
  9. uk_mouse

    uk_mouse Aquatic adventurer

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    I've never had problems removing those bolts on my bike, I've only ever used engine oil on the threads. For what it's worth.
    #29
  10. BigTony

    BigTony Been here awhile

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    I'm going to resurrect and oldie here...found this thread while searching for tips on a problem

    So I actually did manage to strip one of these cam bridge bolts. They were torqued correctly last time but I'm wondering about my torque wrench calibration at this point. I think it was more a problem of my hex bit not fitting entirely square due to tight access and maybe my XXXL mitts and too much force have something to do with it.

    Anyway, I spun my craftsman hex socket attachment in the screw, then tried a T30 torx bit with a ratchet handle and eventually spun that too.

    After regrouping overnight, I realized I could get a straight shot at the bolt if I removed the rear fender, so did that, and then my Dad came to the rescue with tools - we managed to get a little bit of grip in the bit with the better angle, and we first tried a makita battery powered impact wrench, which didn't have enough force to turn the bolt, and then we tried my new favorite tool:

    Something like THIS:
    [​IMG]
    http://toolmonger.com/2009/07/30/impact-drive-impact-driver/
    Basically you whack this thing with a hammer and the force of the blow pushes the bit while rotating it, to knock the bolt loose.

    Honestly I was having visions of having to drill out the bolt, etc and this tool saved me - three whacks with a dead blow hammer and I managed to break the bolt loose.

    Plus in the spirit of Top Gear Jeremy Clarkson this adds one more use for the all-mighty hammer - loosening bolts!

    The threads on the bold looked good, so honestly no idea why it bound so hard but all is good now, and it was kinda fun that my dad saved the day with the old school man-tools...

    Word to the wise - if you do a lot of valve checks like me and/or see any rounding just buy new bolts (they're not expensive)
    #30
  11. veesquared

    veesquared Been here awhile

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    When my allens show a little wear i will use air cutoff wheel and remove the worn area.I use an angle air sander and take off any burrs and make sure the end is flat. Try a very small dab of valve grinding paste on the end of the allen. Clean bolt head before re- stalling.
    #31
  12. rockohlic

    rockohlic Been here awhile

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    had the same problem on the bikes first valve adj.(950 adv) I think Hans at the ktm factory can't hear the little click the torque wrench makes! I won't even tell you what I had to do to remove it!
    #32
  13. BigTony

    BigTony Been here awhile

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    Good tip here - I think I my tools may be due for this treatment
    #33
  14. GLRRA47

    GLRRA47 Adventurer

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    One of the bolts holding the cam bridge down on my bike was bent. Obviously a factory defect bolt. Couldn't even fix it with a die. Apparently the person who did the first valve check didn't notice it and messed up more than one threaded hole. A couple helicoils later and a new bolt all is fine. Be sure everything fits together smooth. The bolts should screw-in all the way - pretty much by finger - then use a good torque wrench to snug them up. It's easy, once the bolt starts OK to want to go ahead and seat it- even if it's a little sticky feeling - but don't do it if it doesn't feel right.
    #34
  15. pdxmotorhead

    pdxmotorhead Long timer

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    Just a thought, if there is enough meat around the hole ,, look at threadserts instead of heli colis.. They are installed like a helicoil but designed for aluminum, they use them on the head studs of heavy power VW cases. I found them once through an aircraft supplier. They have a special tap with them and the threads engage DEEP they are Iconal If I recall so really tough but match AL expansion ..

    Dave
    #35
  16. Katoom72

    Katoom72 Been here awhile

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    #36
  17. Zuber

    Zuber Zoob

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    You can grab the head of these bolts with a small needle nose vice grips. Works great.
    #37
  18. Scribe

    Scribe £Bob£

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    Rounded one the last time I checked the valves. I spent a good three days bemoaning my fate and thinking I was going to have to drop the engine to get a shot at the bolt. I finally ended up grinding the damn thing off (put a rag in the engine to catch the shavings, it was not pretty). New bolts every time now.
    #38
  19. Hair

    Hair Free to a good home.

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    It's been years since I visited this thread. It's been a couple of years since I last owned an LC8. I am thinking of buying another one. It's a little sad to hear that some of you are still having to deal with this issue. On the other hand it's good to hear that it is still a rare occurrence.
    #39
  20. Katoom72

    Katoom72 Been here awhile

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    Enough things you can do to prevent it from happening. People that know the engine expect it and act accordingly to prevent it, LC8 'noobs' get caught by it but it's an easy fix.
    #40