WUMPA - my DMC Dauntless 1150GS Adventure rig

Discussion in 'Hacks' started by DRONE, Apr 26, 2011.

  1. DRONE

    DRONE Dog Chauffeur

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    Nope. This is a GSA drive shaft. It's keyed. Can only go in one way. The GS drive shafts are the one's that are not keyed and can be installed wrong.

    Not to mention that I had the vibrations with the old drive shaft too! I was hoping (3 months ago) that the shaft was the problem but the old shaft was actually in great shape once we pulled it out and inspected it. Since I'd already bought the new shaft for $800 and the whole rear end was taken apart, I went ahead with the replacement. It made no change to the vibrations.
  2. davebig

    davebig Another Angry Hun !

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    Hard to believe you paid up for a new shaft,I don't suppose you want to sell the old one ? I have taken a bit of your advice and have a Lumix on the way as I badly need a camera for my pocket, missed nice shot tonight a young farmer and his 4 y/o son herding about 40 Holsteins across a tiny road I was on for evening chores.DB
  3. DRONE

    DRONE Dog Chauffeur

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    I showed your post to my mechanic and I described the vibrations again. He now thinks that you may be right--it very well might be the output shaft bearing on the transmission. Of course, an expensive repair because of the number of hours of labor needed.
  4. DRONE

    DRONE Dog Chauffeur

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    OK, just heard from my mechanic. Gearbox out and inspected. All bearings in good shape. Output shaft bearing nice and tight. No unusual wear anywhere. The entire gearbox in good shape. Gonna replace all bearings and seals but he told me not to expect any improvement in the vibrations. Should be getting the bike back on Monday as he squeezed me into an already full schedule.
  5. FR700

    FR700 Banned

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    Get him/her to check the end float on the crank while the box is off .

    Does the vibration lesson or go away when you pull the clutch in at speed ?


    .
  6. davebig

    davebig Another Angry Hun !

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    I believe I should insult you at great length about throwing good money after bad, but I'm trying to be less cynical. On the GS mailing list we've already had a gentlemen who insisted on running a synthetic gear lube he overhauled his transmission also, it was noisy before and after which is why I suggested you try a good quality str 90wt industrial gearlube, I already tried pissy gear lubes years ago they where noisy and sucked but the rigs shifted nicer.
    You guys all seem to think BMW is unimpeachable engineers don't build anything bean counters do, the art of engineering is using less to do more.DB
  7. DRONE

    DRONE Dog Chauffeur

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    I only vibrate under power. I have no appreciable vibration when I pull the clutch handle.

    Now I have turned my crosshairs on the shock. Since the Adventure shock is already longer than the standard shock, and my shock is longer than the Adventure shock, my shock I think might be TOO long. I'm thinking that maybe the angle of the drive shaft is too severe and is causing the vibrations. So I'm having my Ohlins guy return it to stock length.
  8. FR700

    FR700 Banned

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    Haven't read where this problem has only surfaced since the lift .

    The steeper shaft angle will shorten the service life of the unis and rob horsepower , yes .

    Rule of thumb says 22 degrees as max for a uni or you need to start looking at a CV joint .

    Save some money ... grab a ratchet strap and cinch down the rear shock to lessen the shaft angle ( might pay to do the same for the chair shock at the same time to negate interesting new traits in the handling ) ... take it for a ride ... report back .



    .
  9. davebig

    davebig Another Angry Hun !

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    Very good idea and information, I have reason to believe your way oversprung anyway at least at the front how much sag does the rig have ? they need to have some.Finding it hard to believe a 61 y/o man with a bad knee needs a rig sprung to desert race.DB
  10. DRONE

    DRONE Dog Chauffeur

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    That's because I never suggested it. The problem surfaced after the lift, but not at once. It was a couple of months later. All I know is that I did not have these vibrations last season and I do have them this season. So something has changed. And that, then, points the finger at either some problem related to wear, or to some modification I made. Since I've pretty much eliminated all of the wear items, that just leaves me with the shock, which is the only thing I changed on the rig last winter.
  11. DRONE

    DRONE Dog Chauffeur

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    My shock info is posted HERE.

    I'm not saying the shock is causing the vibrations. Like I said above, I've swiveled my crosshairs in that direction because there simply aren't any other targets to look at.

    By the way, I used to bottom out both the front and the rear shock. After I resprung the front, it eliminated 90% of the bottoming, but I was still bottoming the rear on occasion. The changes I made to the rear eliminated all bottoming. As a result, I'm now totally happy with the ride both on pavement and off.

    Regarding the sag, I've only measured it unladen. Maybe when I'm at the Bigfoot Rally I can get a couple of guys to help me measure it with me and my gear on board.
  12. FR700

    FR700 Banned

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    Ok , twenty questions time :lol3

    Does it vibrate in neutral when you rev the motor at a standstill? As in under no load ?


    Silly and cheap things to consider ... loosen the alt' belt and see if it goes away .

    Crank end float ( thrust bearings out of spec' ) , cam chain guides/tensioner .


    Can not recall if you added a heavy duty clutch ( ceramic * shudder* button clutch ) ? If the clamping pressure has been upped it will load the thrust bearings .


    .
  13. norton(kel)

    norton(kel) vintage

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    Only 13 days left till departure date of the trip of a lifetime. Better hurry and get it straightened out. :lol3 (I'm not bringing any Beemer tools with me:evil)
  14. dholaday

    dholaday Been here awhile

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    DRONE:

    Did you ever verify Jay's assertion that that your tilt-control problem truly is electric, not mechanical? Maybe [grasping at straws] whatever is going on there is contributing to your vibration.

    More straws - How about your clutch? You changed that out also.

    Didn't you say vibration is only in gears 4, 5, 6? That sure sounds like something in the transmission.

    Duncan
  15. davebig

    davebig Another Angry Hun !

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    I don't think you and I are going to agree on much, FR700 and the driveshaft info seem like the best place to look other than the unimpeachable front wheel bearing and you'd feel that. Good luck on your trip.Changing my back tire made a world of difference.DB
  16. DRONE

    DRONE Dog Chauffeur

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    Tilt--Height of the sidecar suspension using the electric tilt has no effect on the vibrations.

    Clutch--I went to a sintered clutch last September and put on 2000 miles last Fall with no vibrations. Wouldn't it be weird if it turned out to be a latent defect in the new clutch?

    4-5-6--Yup. Just in 4th, 5th and 6th.
  17. davebig

    davebig Another Angry Hun !

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    As I remember you where talking about a rear tire change and not liking a 175/65 you had on have you changed the rear again ? The Nitto I just took off was much harher than the Blizzak I installed.DB
  18. DRONE

    DRONE Dog Chauffeur

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    Neutral--No. Only vibrates in 4th, 5th and 6th. And the vibrations are different in each gear.

    Loosen the belt--Not sure I understand where you're going with this one. Seems like anything to do with the belt would be consistent in all gears?

    The other stuff--if the problem is not the shock I'm gonna sell the outfit this Fall after I get back from the CDT and let some other guy sort it out. I'm not a mechanic and really can't afford to pay somebody to take the motor apart. I'm pretty much tapped out. I don't even know what a thrust bearing is or why clamping pressure loads them. All of that is way over my head. Some BMW mechanic can buy it from me for cheap, fix it over the next weekend, then re-sell it for a profit. Although I might do better parting it out since I've got some decent farkles. Either way I won't have Davebig lecturing me any more.
  19. davebig

    davebig Another Angry Hun !

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    Do I owe you an apology ? it seems to me you referred to me as a bullshit artist and have more of less inferred that I'm a liar,I'll admit to being loud an opinionated.
    I am not responsible for how you feel or your behavior.I've found allot of your stuff very helpful and short of driving to Tacoma to fix your rig for you or teach to do maintenance,thankyou for your counsel, and do have a safe trip.DB

    “Holding on to anger is like grasping a hot coal with the intent of throwing it at someone else; you are the one who gets burned.”
    ― Gautama Buddha
  20. FR700

    FR700 Banned

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    What this points to is that the cause is forward of the clutch ... that is if you haven't checked all engine-frame mounting bolts for correct torque . Correct torque and tightening sequence play a critical part for some bikes in eliminating unwanted vibration . If I recall you take the chair off to take the bike to the dealer so maybe something was missed in the tightening procedure when put together last ?

    That the vibration alters in different gears is because the engine is seeing a different load under torque due to gearing multiplication combined with torque loading . The higher the gear the more vibration would be my wild ass guess at this point ?

    Alternator , was trying to see if the vibrations are emanating from bad bearings/partially seized . Disconnecting the drive to it would show it up fast .

    As for thrust bearings , the crank wants to move fore and aft during rotation and the thrust bearings ( which come in different thicknesses and are either part of a main bearing or come as a half moon part or a shim on the back of the crank between the flywheel as on airheads) limit this to a predefined limit set by the engine manufacturer . A heavier clutch clamping force does reduce clutch slip ... but the price/penalty is that those thrust bearings get a higher shock loading when the clutch is fed in . Ceramic button clutches do them no favors at all added into the mix is that the button clutch is more ... um ... brutal ... when it does engage .

    Bad cam chain tensioner/guides will also exhibit symptoms of vibrations under certain circumstances . There is a known fix for those regarding oilheads ( g-spot would yield more reading for you ) .









    That would be a pity from my way of thinking but that call is up to you ( selling it ).

    Staring over would not guarantee anything other than working on a new outfit .


    Have fun and feel free to pm if you have any questions .

    .