Clank clank voice from... ???

Grignapoco Posts : 175 Join date : 2013-11-07 Age : 79

Hi;
When I pull the clutch lever and relase and pull a half way then relase I hear terrible clank noise coming from bottom which I couldn't decide where it comes from. Is it from transmisson or final drive? Any advice?
Cheers
Onur Kuraner

GRiSO Capo Posts : 10200 Join date : 2013-09-30

Video won't play for me.

CARC reaction rod bush?

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Grignapoco Posts : 175 Join date : 2013-11-07 Age : 79

Thanks Beetle. I will check it

Don Abbondio Posts : 25 Join date : 2014-06-17

It's difficult to see the video, but I gather that you have the bike on the centre stand, rear wheel off the ground. If the rear wheel is not under load, you will get a lot of drive-line lash. It's caused by slack in the system and the uneven firing interval. It's not good for the gearbox and drive-line to do what you're doing.

Grignapoco Posts : 175 Join date : 2013-11-07 Age : 79

No, no. It was not on center stand, ı was driving in first gear. I wraped the camera behind my seat. That's why it was too shaky. I tried the record the sound.

GRiSO Capo Posts : 10712 Join date : 2013-05-29 Age : 67

Onur, listening to it it sounds like the racket made by the face cam shock absorber being incorrectly set up at the factory.

On some of the early 1100's, both GRiSO and Breva, there was an issue with the stacked washers that act as a spring for the shock absorber collapsing over time, this led to the face cams not being loaded sufficiently and the horrible knocking noise is them lashing about under a light and inconsistent load.

There was a service bulletin on this back in the day and the 'Fix' is to insert some more shims under the 'Spring' retainer collar. This requires disassembly of the box and, sadly, isn't guaranteed to fix the issue permanently although it will improve it.

The factory say that the noise won't cause any long term problems but this may just be a way of them trying to wriggle out of their responsibilities at the time. Michael and I have sone several over the years with mixed success in eradicating the noise. None of them have blown up.

Pete

Grignapoco Posts : 175 Join date : 2013-11-07 Age : 79

Thanks for valuable info Pete. If you mentioned about MG Technical note 011-2006, I installed 2 shaped washers (part #95129340) 6 months ago. Clanck voice diminished a little. It was worst then you heard in video.But if you were telling about some other part, could you please send me that service note to my email [You must be registered and logged in to see this link.] if possible. Since there is no legal MG service in Turkey I was thinking to bring the bike to Greece which Petar Petkov from Macedonia (this forum member, and good friend) recommended.
Thanks again for your interest,
Cheers
Onur Kuraner

Tanabuso Posts : 93 Join date : 2019-03-17 Age : 52

The noise happens when you are moving the clutch lever in and out while rolling down the road??? Thinks its the slack in the driveline. The load in the carc is basically shifting from the drive gear to the driven gear and back again as the clutch is operated.

My old shaft drive ATV would make a similar noise when I chopped the throttle then gassed it again.

Grignapoco Posts : 175 Join date : 2013-11-07 Age : 79

You are right, but how come BMW or shaftdriven Honda runs smoothly without any noise?

L'Innominato Posts : 3426 Join date : 2013-05-29 Age : 65

okuraner wrote:: ...how come BMW or shaftdriven Honda runs smoothly without any noise?

Because they're not made by Guzzi?

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Tanabuso Posts : 93 Join date : 2019-03-17 Age : 52

Street has yhe best reason I could come up with.
Just like in a company work van.... mysterious noises miraculously disappear when you turn up the radio (or exhaust note).

GRiSO Capo Posts : 10712 Join date : 2013-05-29 Age : 67

okuraner wrote:: Thanks for valuable info Pete. If you mentioned about MG Technical note 011-2006, I installed 2 shaped washers (part #95129340) 6 months ago. Clanck voice diminished a little. It was worst then you heard in video.But if you were telling about some other part, could you please send me that service note to my email [You must be registered and logged in to see this link.] if possible. Since there is no legal MG service in Turkey I was thinking to bring the bike to Greece which Petar Petkov from Macedonia (this forum member, and good friend) recommended.
Thanks again for your interest,
Cheers
Onur Kuraner

I don't have access to the service site any more because I'm no longer an 'Official' service agent but it sounds to me like the repair you carried out is the one in the tech bulletin.

The thing is I don't think they ever got to the bottom of why the washer tower was collapsing. With the introduction of the 8V though the face cam shock absorber was deleted and thedriveline relies entirely on the bonded 'Rubber' insert in the cardan shaft for shock mitigation. With the 1400's, which have no rubber insert, the face cam shock absorber made a reappearance.

As to why BMW's and Honda's don't 'Clank' as badly? I am not familiar with their drive lines so I can't really hazard a guess.

Pete

Don Abbondio Posts : 6086 Join date : 2014-03-13 Age : 69

Sounds like mine does - the front bush is buggered or the holes elongated. But, I have been wrong before and daresay I will again.

GRiSO Capo Posts : 1329 Join date : 2015-08-09 Age : 60

+1 for reaction rod bush...

GRiSO Capo Posts : 10712 Join date : 2013-05-29 Age : 67

Generally I find if it's the bush you'll get a big 'Clank' when you engage first gear but feeding out the clutch doesn't make weird noises. The 'Chattering Clank' tends to be the face cams rattling against each other as the uneven power pulses and clutch slip come into play. Not saying I'm right as I have limited experience with either problem. (Shrug.)

Pete