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Light rattle in gearbox when pushing my bike.


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1 hour ago, Walterg said:

Thanks guys.

I finally had some time to dig into this issue and I started taking parts off and now I'm quit convinced it indeed has to do with the clutch.
I never roll the bike with any of the gears engaged and the clutchlever pulled in simply because it's heavier and less easy to do. This time it just
happened to be so and I heard the noice for the first time.
The driveshaft looks fine. No play in any direction. It's also not making any noise.
Took the side panel of the transmission off and everything looks and feels as it should. Also no play on any bearings.
At this point I could cleary hear the sound coming from the rear side of the engine but as the crankshaft is not turning it has to be the clutch!

Reading some of your comments about the noisy clutch I'm starting to think I am being worried about a problem that does not exist. So now i'm thinking that
I just assemble my bike again, put in new transmission oil, do something about rainwater getting into the gearbox ventilation and go riding.

On a side note: I must have moved my bike this way before in the past but I don't recall hearing any of this noise. It's allways the brakepads that
make most of the noise. Could it be that the clutch is wearing out and that that's the reason it's making more of that metallic sound?

Yes and yes. It's a twin plate dry clutch with a gazzillion splines on the clutch hub and flywheel. What are the odds that it's going to be silent in the conditions you mention? Don't worry I'll tell you, ZERO. The older it gets the more the splines wear and the more rattly they become.

Phil 

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Sorry but I'm still/again having some doubts about whether I can ride my bike without making things worse so I made a 10 second video. The reflection on the painted wall shows what I'm doing and you may have to turn up the volume when you play it.


Transmission rattle video with sound

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Check to see that both ends of your driveshaft are tight on the splines. I had a similarly disconcerting noise when pushing and found that my rear yoke was less than 'very' tight. 
I have to add that I only discovered it upon disassembly, and I replaced the outer housing bearing; the 'rattle' was gone upon reassembly. So I attributed it to the drive spline coupling. Grab your rear housing to see how much play is in that outside bearing, also.

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Late to this, so to clarify...

The rattle when pushing is only when the bike is in gear, and clutch lever pulled in.

Is it safe to assume that the noise is absent when pushing the bike in neutral (whether clutch is activated or not)?

Have you tested different gears? Does the noise speed up or slow down as you change gears?

Do you have a way to lift the rear wheel? If so, you can bind the clutch lever in (zip-tie or bungee), then rotate the wheel while changing gears and listen for noises.

With the wheel up, it will also be easier to look for play in the driveshaft.

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I have no clue, but as @Scud said you've got to try to narrow down when the rattle is occuring.

It doesn't sound like clutch plates to me, but I don't own a V11 and basing my experience on earlier bikes

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Yeah Weegie. Now that I have reassembled the bike and was able to reproduce that sound again, I changed my opinion about what's causing the rattle and I don't think it's the clutch. The sound is not that "Metal plate jingling" kind of sound. It's more like gears just touching each outher when turned.

My answers to Scud's questions:

The rattle when pushing is only when the bike is in gear, and clutch lever pulled in.
Answer>> Yes, that's correct.

Is it safe to assume that the noise is absent when pushing the bike in neutral (whether clutch is activated or not)?
Answer>> Yes. No sound whatsoever.

Have you tested different gears? Does the noise speed up or slow down as you change gears?
Answer>> Interesting. The sound is different per gear. 
In first gear the rattle is the loudest and has the highest frequenty (RPM). Going up the gears seems to make the rattle a bit quieter per gear.

Do you have a way to lift the rear wheel? If so, you can bind the clutch lever in (zip-tie or bungee), then rotate the wheel while changing gears and listen for noises.
Answer>> Besides making a few steps back and forth with the bike everytime I also lifted the rear wheel for testing.

With the wheel up, it will also be easier to look for play in the driveshaft.
Answer>> The drive shaft is fine. No play in any direction (I love lubing that thing ;) ) and the bearing through which the splined shaft exits the gear box has no play at all. There's also no play on the splined shaft itself in any direction.

Note:
When I turn the drive shaft (the rear wheel) and change direction there is always a few degrees of play at first but I think that's normal as the gears change direction and change sides on the gear tooth.

It looks like I will be draining and opening up the gearsbox soon again.

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That's a tough 'telephone diagnosis'. 

Are there cushion springs in 6 speed clutch friction discs? Big trucks break those springs all the time. Could be a bit out of place, protruding just enough to clack against the flywheel. 
 

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Goodness me, listening to the clip I wouldn't categorize this as a slight rattle! "rhythmic light clunking" in my book but I can see how some would call it a rattle. Differences in language interpretation. It's a serious sound and I wouldn't ride the bike until I sourced the issue. It sounds like it's a gear selector sleeve catching on the drive teeth of one gear. So either the selector assembly is seriously out of adjustment or there is a partial failure in it somewhere. Is this bike fitted with a satin black gearbox or a wrinkle finish gearbox? There is also the issue of a failed selector sleeve which was covered by a recall on early boxes but if it's an early wrinkle finish gearbox they were affected as well and you need to account for ones that slipped through the net. You also need to account for replacement transmissions from previous owners and just a sleeve failure. It might also be worth looking at the large eccentric adjustment which people fiddle with when installed. It sounds like it's trying to engage 2 gears at once or not fully disengaging one gear when engaging another. It could also be a loose input shaft drive spline. I think doccs had that. You've also had the selector apart to replace the spring. Are the selector fork gear wheel teeth correctly indexed?

Phil

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I took the gearbox of the bike and tried to reproduce the sound by turning the drive shaft and changing gears.
Nothing....No rattle or clunking or any other disconcerning sounds. Just that light whizzing sound of gears turning smoothly.
I tried several gears with and without trying to simulate some load on the primary gearshaft by holding the gear that "interacts" (Don't know the
correct word for that) with the clutch but all sounds great.
Anything I can try at this point?
I'm thinking now that maybe the clutch mechanism is making that allthough I wouldn't know how....I'm still trying to figure out how to remove the clutch assembly.


Clutch picture.
Picture of the gear that engages with the clutch.
View inside the gearbox.
Picture of my test setup.

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Here's a short video showing reassembly. Disassembly obviously is the reverse order of operations. 
There is a tool to center your clutch discs without taking off your transmission drive gear, likely available from a vendor or member nearer to you.
 

 

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...and as Pete says above, be certain the shaft retaining nuts are tight. On my 'Sport, the driveshaft has a spring to maintain a bit of pressure on the joints, I suppose to insure they don't walk off the shafts if (when) they get loose. If the output shaft nut (on 5 speed) comes loose, the pressure drives the shaft forward until the gears are so far out of alignment you can't shift them.

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On 7/10/2022 at 4:28 AM, Walterg said:

Sorry but I'm still/again having some doubts about whether I can ride my bike without making things worse so I made a 10 second video. The reflection on the painted wall shows what I'm doing and you may have to turn up the volume when you play it.


Transmission rattle video with sound

Sounds like a Teo Lamers centerstand dragging on the ground.  Do you have a vid of the bike rolling in neutral, clutch out? If there was no noise under those conditions, then the trans "should be" fine. Points to the clutch or something in the clutch housing. Loose bolt or bit of clutch lining banging around?

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6 hours ago, Walterg said:

I took the gearbox of the bike and tried to reproduce the sound by turning the drive shaft and changing gears.
Nothing....No rattle or clunking or any other disconcerning sounds. Just that light whizzing sound of gears turning smoothly.
I tried several gears with and without trying to simulate some load on the primary gearshaft by holding the gear that "interacts" (Don't know the
correct word for that) with the clutch but all sounds great.
Anything I can try at this point?
I'm thinking now that maybe the clutch mechanism is making that allthough I wouldn't know how....I'm still trying to figure out how to remove the clutch assembly.


Clutch picture.
Picture of the gear that engages with the clutch.
View inside the gearbox.
Picture of my test setup.

Whats it sound like rotating with the gearbox cover on and in gear?

Phil

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