Clattering noise from gearbox

[Glenn Thorpe]

Hi,

This is my first post, I've had a 2013 Stelio for a year now and really like everything about it. My past experience was with few different BMW oil heads.

I'm asking about a weird noise that I hope is not a problem. I first noticed it today riding around the neighborhood after installing a new set of driving lights (I didn't have a helmet on so I heard a lot more noises).

It sounds like a clattering in the gearbox area (or maybe driveshaft). It sounded like loud tappets so I turned the engine off and coasted.
- With clutch lever pulled in the rate of clattering was greater in 1st gear, and slowed as l upshifted.
- No clattering in neutral

Is this normal? or do I have a problem?

Thanks

 

[canuck1969]

At idle and stopped, with the clutch pulled in, does the noise go away and then when you release the clutch the noise comes back. If so, normal. It's the gears spinning on the input shaft. If the noise is there with the clutch in and out then not normal. Can't say I have ever listened to this bike when coasting with the engine off so not sure what would be normal. Every other bike I have had was silent other than the whirring of the gears.

 

[GTM®]

First congrats and welcome to the GT Forum and Guzzi Famiglia. Hope you'll add your info to the Registry page.
CARC Guzzis have a lot of driveline and clutch noise. The clutch is reverse of a Ducafi, meaning it makes its noise when the lever is out, not in. The trans does make noises, as does the rear drive, especially if running on the center-stand (don't do it, it will cause you undue stress), as it's designed to function with a load on it.
All in all, it sounds like everything is perfectly normal to me, without actually hearing anything that is. Hope that helps.

 

[WayneOrwig]

It sounds like a clattering in the gearbox area (or maybe driveshaft). It sounded like loud tappets so I turned the engine off and coasted.
- With clutch lever pulled in the rate of clattering was greater in 1st gear, and slowed as l upshifted.
- No clattering in neutral

Is this normal? or do I have a problem?

Lever pulled, worse in first gear. That is likely the clutch. And it is likely normal clutch plate noise. I only notice it on mine if pushing it around a parking lot, in gear, with the lever pulled.

Do you have a problem. Well, you bought a Moto Guzzi.

 

[Glenn Thorpe]

At idle and stopped, with the clutch pulled in, does the noise go away and then when you release the clutch the noise comes back. If so, normal. It's the gears spinning on the input shaft. If the noise is there with the clutch in and out then not normal. Can't say I have ever listened to this bike when coasting with the engine off so not sure what would be normal. Every other bike I have had was silent other than the whirring of the gears.

Canuck,

The noise was not present at idle with bike stopped. It only happened when the bike is moving with clutch pulled in and in gear. I just noticed it yesterday. Last night after posting I noticed it again.

This was apparent when coasting with engine off. Both times the bike was not at full operating temp though (just spinning around the neighborhood)

However today on the way to work not noise at all !

Maybe this is like the clutch groan phenomena ? I could attribute it to cool operating temp....

 

[canuck1969]

Lever pulled, worse in first gear. That is likely the clutch. And it is likely normal clutch plate noise. I only notice it on mine if pushing it around a parking lot, in gear, with the lever pulled.

Do you have a problem. Well, you bought a Moto Guzzi.

Wayne, think we have had this conversation before. Single plate clutch on the stelvio. There should be no clutch noise with the lever pulled in (clutch disengaged). When the lever is out (clutch and gearbox shaft engaged) you will hear rattling. On mine (and others I have witnessed), the rattling is coming from the gears rattling around on the input shaft (or actual play in the shaft depending on who you listen to) at idle in neutral. due to the pulses from the engine. Once you go above idle in neutral or pull the lever in (clutch and gearbox disengaged) the noise should go away.

Glenn, may be nothing but might be worth stopping by the dealer and let them have a listen as it is hard to diagnose here. The groan that people experience is usually gone after the first 30 seconds or so of riding and it is not a rattle but an actual groan so I don't think that is your issue. Again, the driveline does make a lot of noise, most normal but this one seems a little strange. If you coast in neutral at slow speeds (less than 10-15 MPH), the gear box rattle will still be there and that is normal. If you give it a little gas to bring the RPM's up it should go away. If not, talk to the dealer.

When you say it was not apparent at idle, was it in neutral with the clutch lever out? If it is perfectly quiet with the clutch lever out (some do not make any noise) or in at idle and in neutral, and it is shifting normally without the clutch grabbing or slipping then I don't believe it to be clutch related.

 

[Glenn Thorpe]

First congrats and welcome to the GT Forum and Guzzi Famiglia. Hope you'll add your info to the Registry page.
CARC Guzzis have a lot of driveline and clutch noise. The clutch is reverse of a Ducafi, meaning it makes its noise when the lever is out, not in. The trans does make noises, as does the rear drive, especially if running on the center-stand (don't do it, it will cause you undue stress), as it's designed to function with a load on it.
All in all, it sounds like everything is perfectly normal to me, without actually hearing anything that is. Hope that helps.

Thanks Todd, I'll add my info to the registry page.

 

[kiwi dave]

There should be no clutch noise with the lever pulled in (clutch disengaged). When the lever is out (clutch and gearbox shaft engaged) you will hear rattling. On mine (and others I have witnessed), the rattling is coming from the gears rattling around on the input shaft (or actual play in the shaft depending on who you listen to) at idle in neutral. due to the pulses from the engine.

First plausible explanation I've read about this. I guess the same would apply to other single plate models like the Scura, Tenni, and the ill-fated single plate EV Touring which also exhibited this behaviour.

So why don't twin plate clutches exhibit this behaviour and instead rattle when the clutch lever is pulled in? Perhaps they do, but the rattle of the twin plates is louder than when the lever is released?

 

[GuzziMoto]

I thought we had discussed this a while ago. The clutch itself should not rattle when engaged, except possibly a very small rattle from the throw-out mechanism. The plates themselves clearly cannot rattle when they are being squeezed together.
I assume that people are more likely to notice the noise when the clutch is engaged when there is no noise when the clutch is dis-engaged (lever pulled in). As I don't have a twin plate Guzzi I can't really say, but I have spent some time on Ducati's and they definitely rattle but the dry clutch motors make a louder racket when you pull the clutch in. Funny enough, the wife's Ducati is a wet clutch motor (Monster 1100).
The gears in the input shaft can rattle with the pulsing of the pistons firing when the clutch is engaged but the trans is in neutral. On some bikes I have had the noise was not always the same every time you let the clutch out in neutral.

 

[canuck1969]

First plausible explanation I've read about this. I guess the same would apply to other single plate models like the Scura, Tenni, and the ill-fated single plate EV Touring which also exhibited this behaviour.

So why don't twin plate clutches exhibit this behaviour and instead rattle when the clutch lever is pulled in? Perhaps they do, but the rattle of the twin plates is louder than when the lever is released?

Only explanation I have is the difference between actual clutch rattle (2 plate clutch lever in) and gear box rattle (single plate clutch out). Not all gearboxes rattle but most will get is to some extent as they get older. Mine never did it at first but after 10k kms or so it started. Has been doing it for the last 40,000 km so not too worried. TB sync makes a huge difference. I always know it is time for a sync when the rattle gets louder. Once it is in perfect balance the rattle goes down as the pulses are more cyclic.

 

[Glenn Thorpe]

Wayne, think we have had this conversation before. Single plate clutch on the stelvio. There should be no clutch noise with the lever pulled in (clutch disengaged). When the lever is out (clutch and gearbox shaft engaged) you will hear rattling. On mine (and others I have witnessed), the rattling is coming from the gears rattling around on the input shaft (or actual play in the shaft depending on who you listen to) at idle in neutral. due to the pulses from the engine. Once you go above idle in neutral or pull the lever in (clutch and gearbox disengaged) the noise should go away.

Glenn, may be nothing but might be worth stopping by the dealer and let them have a listen as it is hard to diagnose here. The groan that people experience is usually gone after the first 30 seconds or so of riding and it is not a rattle but an actual groan so I don't think that is your issue. Again, the driveline does make a lot of noise, most normal but this one seems a little strange. If you coast in neutral at slow speeds (less than 10-15 MPH), the gear box rattle will still be there and that is normal. If you give it a little gas to bring the RPM's up it should go away. If not, talk to the dealer.

When you say it was not apparent at idle, was it in neutral with the clutch lever out? If it is perfectly quiet with the clutch lever out (some do not make any noise) or in at idle and in neutral, and it is shifting normally without the clutch grabbing or slipping then I don't believe it to be clutch related.

Canuck, I do have the clutch groan that goes away once up to operating temp (I thought the clatter may somehow be associated with that).

The clatter only happens when bike is moving, clutch disengaged, and in gear. Not loud enough to notice when the engine is running but can only hear it while coasting & engine off (on a safe side street).

No noise at all in neutral with clutch engaged or disengaged; moving or stopped.

No noise stopped at idle with clutch disengaged and in gear (or in neutral).

Anyway, its good advice to bring it in to the dealer and have it checked. I'm traveling for work the next few weeks but will try over the holiday break.

 

[WayneOrwig]

So why don't twin plate clutches exhibit this behaviour and instead rattle when the clutch lever is pulled in? Perhaps they do, but the rattle of the twin plates is louder than when the lever is released?

The twin plate clutch has a floating 'cup' in the center that the pushrod presses. When you pull the lever and press that cup, it can't rattle. When the lever is released, that cup can float around a little and rattle. I often lightly 'glue' the cup in to keep it in place during assembly, and to eliminate the rattle.

 

[WayneOrwig]

Wayne, think we have had this conversation before. Single plate clutch on the stelvio. There should be no clutch noise with the lever pulled in (clutch disengaged).

Like I said, mine makes a noise when I pull in the clutch to push the bike around, while in gear. I guess that it is the springs in the clutch plate itself just rattling around as the clutch plate slowly turns.

 

[WayneOrwig]

Canuck, I do have the clutch groan that goes away once up to operating temp (I thought the clatter may somehow be associated with that).

The clatter only happens when bike is moving, clutch disengaged, and in gear. Not loud enough to notice when the engine is running but can only hear it while coasting & engine off (on a safe side street).

No noise at all in neutral with clutch engaged or disengaged; moving or stopped.

No noise stopped at idle with clutch disengaged and in gear (or in neutral).

Yep, mine has done that for years and over 50,000 mile.

My guess, is the springs are just rattling / floating around in the clutch plate at low speeds.
The clutch is made something like this picture. Those spring are captured, but can flop around some.

 

[Glenn Thorpe]

Yep, mine has done that for years and over 50,000 mile.

My guess, is the springs are just rattling / floating around in the clutch plate at low speeds.
The clutch is made something like this picture. Those spring are captured, but can flop around some.

Wayne,

That makes sense, thanks for taking the time to explain that for me.

 

[kiwi dave]

The twin plate clutch has a floating 'cup' in the center that the pushrod presses. When you pull the lever and press that cup, it can't rattle. When the lever is released, that cup can float around a little and rattle. I often lightly 'glue' the cup in to keep it in place during assembly, and to eliminate the rattle.

Not my experience, Wayne. The twin plate rattles when the lever is pulled, not when it's released. The single plate versions are the opposite.

 

[WayneOrwig]

Can't argue on the twin disks, as I am half deaf.

I do know, as Glenn encountered, on my Stelvio, when I pull in the clutch lever and walk the Stelvio across the parking lot as I do almost daily where I work, it goes CLICK-CLICK-CLICK-CLICK-CLICK. And it is pretty loud. Makes you wonder the first time I heard it.