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Anybody recognize this knocking sound?


Hansson

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After I changed the friction plates and the steel intermediate plate and sealed the leaking gearbox, there are a tapping sound somewhere around the gearbox and clutch. I can't locate the noise. It's possible to silence the noise, if you quickly engage the clutch. But after a while occur the tapping sound again. 

 

The splines on flywheel is a bit worn. Could that be the reason? Maybe the intermediate plate and the clutch pressure plate strikes the flywheel in it's worn splines and make the noise? The clutch gear is in good condition. Or is the sound coming from the gearbox? Please tell me if you have experience of that sound, or an idea to the cause.

 

Open the link and listen! (You hear when I engage the clutch)

 

https://drive.google.com/open?id=0B1cTu58Dx28vVFIyS0hkejdqYlU

 

Ciao

Jörgen

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My 100,000 miles twin-plate clutch is really noisy at idle in neutral, but it's more of a *rattle* than a "knock."

 

Even with the clutch pulled in, yours sounds odd? Like a scraping?

 

Is there a typical "throw out bearing" in this set-up?

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The throwout bearing is really small. It sits between the slave cylinder's piston and the pushrod. It could not make that much noise.

 

I'm assuming you have not ridden the bike yet - and that you noticed the sound on your first start-up after the repair.  I'm also going to assume that you did not remove the flywheel.

 

Are you certain that all the springs are in correctly and that everything is properly tightened?

 

If you put your ear to a wood dowel, you can touch the dowel to different parts of the case to try to isolate the noise.

 

Did you replace or re-use the springs? When I did my twin-plate clutch recently (due to slippage), it seemed that the plates still had some life in them, but the springs were much weaker than the new springs. I wonder if weak springs could allow things to rattle around more than they should.

 

At some point you'll have to decide whether to take it out for inspection or to ride it. I hate those decisions... wish I had an easy answer for you. If you do take it out, it might be a good idea to replace the throwout bearing and springs - just for good measure.

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The one constant scraping sound that exists when the clutch is pulled in , is (in my opinion) the throwout bearing .The other sound(s) I am not sure of . I am sure you will have to disassemble the clutch to find the problems.

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The throwout bearing... ...could not make that much noise.

 

I probably should not have said that about the noise - that was speculation on my part.

 

The one constant scraping sound that exists when the clutch is pulled in , is (in my opinion) the throwout bearing .The other sound(s) I am not sure of . I am sure you will have to disassemble the clutch to find the problems.

But I am assuming the noise is new - and therefore most likely due to something that was changed.

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At some point you'll have to decide whether to take it out for inspection or to ride it. I hate those decisions... 

 

Are you certain that all the springs are in correctly and that everything is properly tightened?

 

Yes, it is exactly as you say Scud. I also hate those situations!! I did the work to replace the clutch at the start of the season and made the decision to ride the bike. I actually rode to the end of the season. The knocking noise has not changed over time, and yes it started after the clutch job. 

 

I also replaced the springs with new ones at the clutch replacement. I'm pretty sure that the springs are correctly fitted and that everything is properly tightened.

I have done the "put your ear to a dowel trick" without success to locate the noise.

 

 

Have you put it in gear and let out the clutch? Does it engage and go through the gears?

 

 

The noise goes through gear one to six, and in neutral.

 

There is one point (in addition to the clutch is pulled in) when the noise is silenced, and that's when the bike is driving. Or when the bike is lifted on the paddock stand, engine run in gear and I brakes lightly.  I think that exclude faulty throwout bearing.

 

I told about the worn flywheel, and here is a pic of it.

There was no noise before I replaced the clutch even though the flywheel was worn, but maybe the changed position of the intermediate plate and the clutch pressure plate due to new thicker friction plates has something to do with the noise problem? 

 

Jjjes%20Iphone%20012_zpsmdlemtkb.jpg

.

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I'd say it could.. I've seen worse, but.

 

I suppose I should say that everyone here knows to *never* sit at a stop light, etc with the lever pulled to the bars, right? I was riding with some SoCal guys that were maybe beemer converts :huh2: that never dropped into neutral when coming to a stop. I tried to explain the clutch/intermediate splines rattling back and forth because of the uneven firing order and said don't do that.

It met with glassy looks. :oldgit:

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I'd say it could.. I've seen worse, but.

 

I suppose I should say that everyone here knows to *never* sit at a stop light, etc with the lever pulled to the bars, right? I was riding with some SoCal guys that were maybe beemer converts :huh2: that never dropped into neutral when coming to a stop. I tried to explain the clutch/intermediate splines rattling back and forth because of the uneven firing order and said don't do that.

It met with glassy looks. :oldgit:

I wish I understood this better. :blink:

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I'd say it could.. I've seen worse, but.

 

I suppose I should say that everyone here knows to *never* sit at a stop light, etc with the lever pulled to the bars, right? I was riding with some SoCal guys that were maybe beemer converts :huh2: that never dropped into neutral when coming to a stop. I tried to explain the clutch/intermediate splines rattling back and forth because of the uneven firing order and said don't do that.

It met with glassy looks. :oldgit:

I wish I understood this better. :blink:

 

 

 

me too!

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I'd say it could.. I've seen worse, but.

 

I suppose I should say that everyone here knows to *never* sit at a stop light, etc with the lever pulled to the bars, right? I was riding with some SoCal guys that were maybe beemer converts :huh2: that never dropped into neutral when coming to a stop. I tried to explain the clutch/intermediate splines rattling back and forth because of the uneven firing order and said don't do that.

It met with glassy looks. :oldgit:

What did you expect ?

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Hansson , the flywheel looks awful . It should be ( if at all possible ) replaced . This may not fix your noise but the teeth are in bad shape . When this is done you should use a dry film graphite spray or a good anti-seize lube on the splines on anything with splines .

 The clutch release bearing (as shown in parts diagram) is a Torrington bearing and appears to be where the sound is coming from .

The part # is 12 08 70 01 in the 2002 V11 LeMans parts catalogue . 

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When this is done you should use a dry film graphite spray or a good anti-seize lube on the splines on anything with splines.

 

Can you say more about that? I mean, would you basically spray the whole inside of the flywheel and the transmission input gear? And do you mean anti-seize paste - like the silver (or copper) stuff you put on bolt threads? My BMW specifies a Staburags (NBU 30 PTM) grease for the splines, which is so thick and sticky you have to brush it on. But the splines on the BMW are tiny in comparison to the Guzzi splines. I have some of that.

 

I just put a clutch back together yesterday, but didn't lube it. It's easy-access now... any extra advice appreciated.

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When this is done you should use a dry film graphite spray or a good anti-seize lube on the splines on anything with splines.

Can you say more about that? I mean, would you basically spray the whole inside of the flywheel and the transmission input gear? And do you mean anti-seize paste - like the silver (or copper) stuff you put on bolt threads? My BMW specifies a Staburags (NBU 30 PTM) grease for the splines, which is so thick and sticky you have to brush it on. But the splines on the BMW are tiny in comparison to the Guzzi splines. I have some of that.

 

I just put a clutch back together yesterday, but didn't lube it. It's easy-access now... any extra advice appreciated.

Gstallon's comment about dry film lubricant is good advice. I've been spraying every spline and sliding surface I uncover with molybdenum disulphide solid film lubricant labelled MIL-PRF-46147D.

Everlube makes a spray called Perma-Slik G which meets MIL-PRF-46147C. http://www.skygeek.com/everlube-perm-silk-g-air-dry-mos2-solid-film-lubricant-16-oz-tube-mil-l-23398d-ppsgae.html

It is an air drying, MoS2 based solid film lubricant in an epoxy binder system, giving low friction, good corrosion resistance, and high load carrying capacity.

Even better is Everlube 620, but the coating needs to be baked at 150ish degrees C, which is inconvenient for some parts.

This type of coating won't give any protection from hammering loads, but will extend the life of sliding surfaces. Chuck's comment about using neutral at stop lights is good advice on avoiding hammering loads in the clutch.

 

After the coating is cured, splines still benefit from high temp grease or HT Grease with MoS2 added (but not in the clutch of course). This grease is important to protect against fretting corrosion.

I looked up STABURAGS NBU 30 PTM to find out more about it. It looks like a perfect spline grease, but I'd be reluctant to put it in the clutch area as it could attract abrasive dust and become grinding paste. Plus you wouldn't want it to get on the friction faces.

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