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Knocking Gearbox


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Can anyone help? This is my very first post on the forum!

 

I have a 2003 V11 Sport. In neutral the gearbox knocks in phase with the firing sequence.

 

It goes away in gear or when the revs are raised. Bizarely it sometimes goes away by dipping the clutch.

 

Do I need to strip the gearbox and look for shot bearings?

 

Thanks!

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No need to do anything. The rattle is perfectly normal/standard. Most owners think it would be the clutch that is so noisy, so for a newbe you're on the right track right from the start :)

Synchronising the engine won't help either, btw. It's the combo straight cut gears (with enough play) with an irregular firing order.

 

Hubert

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Can anyone help? This is my very first post on the forum!

 

I have a 2003 V11 Sport. In neutral the gearbox knocks in phase with the firing sequence.

 

It goes away in gear or when the revs are raised. Bizarely it sometimes goes away by dipping the clutch.

 

Do I need to strip the gearbox and look for shot bearings?

 

Thanks!

Its the clutch and a little gearbox as well,but mainly the clutch.You will find if you dip the clutch quickly it will be almost entirely eliminated.This is the two friction and the intermediate plates realigning in the flywheel and taking out the slack so it doest rattle and clunk.If you dip the clutch slowly it will still tend to rattle/clunk at idle.

I just give the clutch a flick if I'm warming it up so its quiet.

Ciao

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Don't understand why the clutch would rattle if it is engaged. I can imagine it could be noisy when disengaged (clutch lever pulled) as the plates could flop around on their splines but when engaged the springs should hold everything tight - so why would it rattle.

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Don't understand why the clutch would rattle if it is engaged. I can imagine it could be noisy when disengaged (clutch lever pulled) as the plates could flop around on their splines but when engaged the springs should hold everything tight - so why would it rattle.

 

Thank-you all for your considered replies, they put my mind at rest at least until I took the bike out this evening.

 

It would not change out of first gear! I really annoyed the neighbours coming home!

 

Off to seach the forums once again .........

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I must admit, this is one of the (only) annoying traits I find with my V11 Sport.

My theory (for what it's worth) is that the lighter flywheel on these bikes doesn't provide enough inertia to keep the rotation speed of the crank consistent through the full 720° cycle. The compression stage slows the rotation down, the combustion stage speeds it up - and the drive train rattles like a bag of nails because it can't keep up...

I have on old Tonti that I added a RAM flywheel/clutch to years ago and it exhibited the same symptoms. When I got the shits with it and replaced it with an 850T flywheel it idled as smooth as silk...

I've actually thought about adding some weight to my V11 flywheel to smooth out the idle (& test the theory), however I'n sure this would compromise that sweet engine somewhere else in the rev range.

When I need a fix of a sweet idling engine now I just take my 2003 Cali for a spin...

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Don't understand why the clutch would rattle if it is engaged. I can imagine it could be noisy when disengaged (clutch lever pulled) as the plates could flop around on their splines but when engaged the springs should hold everything tight - so why would it rattle.

The drive plates and flywheel/pressure plate are all held together as one unit when the clutch is engeged but the drive plates can still rattle on the gearbox input drive adaptor splines.This is where I believe the noise comes from.I think flicking the clutch causes the drive plates to misalign slightly with each other on the drive splines and take out the slop.Letting out the clutch slowly allows the drive plates to both align on the same side of the splines and creates a little play and it rattles.

Ciao

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Don't understand why the clutch would rattle if it is engaged. I can imagine it could be noisy when disengaged (clutch lever pulled) as the plates could flop around on their splines but when engaged the springs should hold everything tight - so why would it rattle.

 

Thank-you all for your considered replies, they put my mind at rest at least until I took the bike out this evening.

 

It would not change out of first gear! I really annoyed the neighbours coming home!

 

Off to seach the forums once again .........

 

Not shifting out of first gear is another thing entirely. *Assuming* your linkage is ok, it'll be a broken return spring on the transmission. There is plenty of info on this list on fixing that..

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