Clunk like a u-joint

[glib]

On my last couple rides I noticed a clunk reminiscent of a worn u-joint but of course I have a chain on the GS1100ES and it is adjusted well. My son is practicing riding on it right now in a parking lot and I can hear it clearly. I have never done clutch work but I’m wondering if it has to do with the clutch basket springs. It just started without any real buildup so I initially thought something was loose but maybe I didn’t notice it until now.

[Dogma]

If there's a problem with clutch springs, the clutch is either slipping, or the springs are "heavy duty", requiring too much pull on the lever. A loose clutch basket can make a noise, but I've never heard it and can't help diagnose it. Have you double-checked the stuff you "know" is right?

[Burque73]

If it's not clutch related, how about the cushion in the rear hub?

[glib]

If there's a problem with clutch springs, the clutch is either slipping, or the springs are "heavy duty", requiring too much pull on the lever. A loose clutch basket can make a noise, but I've never heard it and can't help diagnose it. Have you double-checked the stuff you "know" is right?

I meant the ones on the back of the basket but I really don't think it's clutch related anyway. It does sound like it could be coming from the hub but the cushions are intact so I think at worst they might allow slop but I don't think a clunk. It is definitely from coming on and off the throttle but it not easily repeated--almost like it happens more when you are not trying. Grr.

[Hinermad]

Could your chain have a stretched spot in it? The chain that was on my old 450 when I bought it did, and I could feel it occasionally when I'd lay on the throttle. The bike would hesitate a little as it took up the slack then surge forward. I couldn't really hear a clunk but I could feel it. A new chain got rid of it.

[Nessism]

The clutch hub nut may have come loose. That's a common problem. APE sells a HD nut or you can get an 1150 nut which is larger and more robust than the 1100E nut.

[glib]

Could your chain have a stretched spot in it? The chain that was on my old 450 when I bought it did, and I could feel it occasionally when I'd lay on the throttle. The bike would hesitate a little as it took up the slack then surge forward. I couldn't really hear a clunk but I could feel it. A new chain got rid of it.

Chain is pretty new. Hub nut is tight. When I hit the rear tire from the side I hear a metal on metal bang. Not sure if it’s related. Still going over everything I can see.

[glib]

So it turned out that the sprocket nuts—all of them—were loose. That is in spite of the lock plates which were loosened somehow. I’ve tightened it all up and the clunk is gone but I’m concerned that the sprocket, which is nearly new, should be replaced because the bolt holes may be oblong now. Definitely want new lock plates. What do you think?

[alke46]

This just doesn't make sense to me. I would think the lock plate would prevent the bolts from loosening. This same phenomenon seems to happen to the clutch hub nut also.

[Steve]

This just doesn't make sense to me. I would think the lock plate would prevent the bolts from loosening.

I saw that happen once when the lock plate was installed incorrectly. Seems the owner had folded the tab against the wrong side of the flats on the bolt head, which allowed the bolts to back out a bit. Not much, but just enough.

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[glib]

I saw that happen once when the lock plate was installed incorrectly. Seems the owner had folded the tab against the wrong side of the flats on the bolt head, which allowed the bolts to back out a bit. Not much, but just enough.

.

I may have done this myself. What is the wrong/right side? I just thought the folded plate tab prevented movement of the nut. Obviously I was wrong but I don’t want it to happen again.

[Steve]

If the tab is folded tightly and completely against the flat on the bolt, it should be good, but sometimes you have to fold it to one side of the point, rather than the flat. You want to fold it against the LEFT side of the flat to keep the bolt from turning to the left.

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[glib]

If the tab is folded tightly and completely against the flat on the bolt, it should be good, but sometimes you have to fold it to one side of the point, rather than the flat. You want to fold it against the LEFT side of the flat to keep the bolt from turning to the left.

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Makes perfect sense. I don’t know how I would have biffed them all but they were all loose so I must have. They will be part of my pre-ride check going forward.

[Brendan W]

If you can't get the left side to flatten up just go around the bike and lean over the saddle.

[habsdoc]

Folding the tab totally flat against the flat of the nut or bolt should stop the bolt or nut from backing out. There is no left side whether it be top or bottom, right or left.