VII Clutch Splines Worn

[Ganzo]

My VII has 65,000 miles on it and since around 40,000 miles the clutch splines have shown signs of wear.  I changed the transmission input gear at 45K, clutch plates at 50K and finally the flywheel today at 65K.  The flywheel splines had the most wear, but was the most expensive piece.  I finally obtained a new one at a good price.  The clutch plates would not fully disengage.  They would always be somewhat bound up because the splines had offset grooves.  So the poor shifting is now like new again.  See attached pictures below.

 

[Camn]

I wonder what it is, that "wears out" the teething most?

 

As I assumed elsewhere here:  when the clutch lever is free (not pressed), the whole "package" inside the flywheel is pressed together and forms "one bundle" . I have marked some V11 clutch part weights down from the German "1100Sport" website: pressure plate 867gr, intermediate plate 266gr, pressure cup 60gr, clutch plates 660gr. This makes a "bundle" of 1853gr, which can move within the teething play, and later within the "wear out",  when the machine idles.

 

Is it the idle or the normal use of the clutch?  Maybe the normal use that creates this wear.

 

Did the clutch noise get bigger (when idling, clutch lever free) as the flywheel spline wear got worse?

[gstallons]

Well, the best cure for this would have been a good coat of dry-film graphite spray on the splines. You could use ant-sieze but it would collect dust and bind ....

[docc]

 

Did the clutch noise get bigger (when idling, clutch lever free) as the flywheel spline wear got worse?

I wonder this as well?

[gstallons]

Probably not. Things are one object when the clutch is released.

[luhbo]

Yes, so it is. The only thing still loose then is the transmission input gear. Wear between this and the plates should produce noise I think.

 

Hubert

[Camn]

What about the weight of the transmission input gear and the shaft, to which it is fixed ?  You could think, that they do not weigh very much and can be "turned easily" (doesn't give noise very much). Then again the "one object" (1,85 kg inside the flywheel) is a mass which is beaten by the "oscillating" flywheel.  It can move within the toothing and create noise when idling. The fact that you can find "low noise setting" by using the clutch few times when idling (the clutch plates maybe center themselves better, less unbalance) could point to this direction; the noise comes from the flywheel toothing/toothed plates?

 

Has somebody the Sachs "racing" clutch plates installed (on a 2 disc clutch) - is there any difference in the "clutch noise" lever pulled / lever free to a "standard clutch"?

[docc]

Looking again at the wear on the flywheel teeth, it appears most on the "left." Does the motor spin counter clockwise from the perspective of sitting on the bike?

 

With the bike in neutral, clutch released, would not the inertia of the clutch parts (all as one) and some portion of the gearbox combine to oscillate between the teeth of the driven flywheel?

[emry]

This is common on many types of clutch drive systems. The wear actually comes from shifting, that why it shows as sweeping type marks on the flywheel (other makes it shows as marks on the clutch basket). Difference between engaged and a disengaged clutch.  Torque is being generated by the crankshaft, and multiplied through the primary gear (clutch assm  and input gear on a guzzi) and then through the trans and rear drive. When the clutch is initially pulled this torque is still being transmitted until the plate slip enough to allow a shift. Once the shift has happened  and the clutch is once again in the process of being released the same effect happens but in the opposite direction, the engine is powering the clutch and so on, as the driven plates slide down the grooves in the flywheel. 

[luhbo]

This is an interesting theory, or observation even. I think you implicitly say that the torque coming from the crankshaft winds up the whole drive train and as soon as you pull in the clutch the stored energy makes the two pressure plates snap in one direction, releasing the clutch then makes them sort of snap in the other direction. Why not, at least it sounds reasonable. Anyway, below you find pix from my clutch at 125.000 km. Actually the same parts are above 170.000km, still 100% functionable.

 

 

I additionally suggest not to wait at red lights or similar in first gear with the clutch pulled in. I think, that's not a defined operation mode and therefore I'd call it 'misuse'.

 

Hubert

[AndyH]

I additionally suggest not to wait at red lights or similar in first gear with the clutch pulled in. I think, that's not a defined operation mode and therefore I'd call it 'misuse'.

I agree - bad practice on any bike but Meriden Triumph ownership teaches this lesson particularly well...!

[gstallons]

BMW airhead bikes will rust the clutch hub splines and the rust will act as an abrasive. The more the rust , the more wear takes place. This happens at a pace that the splines wear out and leave you stranded. This takes place at the rear wheel also.  This is a common problem that is not easily corrected. Preventive maintenance is to remove and lubricate thes parts.

[docc]

While the contact patches on the flywheel teeth are evident on luhbo's pictures, they don't show the marked wear evident on Ganzo's flywheel.

 

With my Sport making the most racket idling in neutral with no clutch, it makes me think that is when the teeth are banging together the most.

 

Of course, there is also 86,000 miles of aggressive shifting up and down. I was planning on a tear down at 100,000 to "do" the heads and such, but may come sooner if the clutch starts to affect shifting quality.

[HaydnR]

This wear is worrying. I think that the flywheel/hub is made of too soft a material (is it ergal?) The teeth on the plates should be made of a softer material as they are a damn sight cheaper to replace than a new hub and flywheel at every clutch change. The 1100 sport flywheel is slightly lighter I think, and looks as if it wears less.

[AndyH]

This wear is worrying. I think that the flywheel/hub is made of too soft a material (is it ergal?) The teeth on the plates should be made of a softer material as they are a damn sight cheaper to replace than a new hub and flywheel at every clutch change. The 1100 sport flywheel is slightly lighter I think, and looks as if it wears less.

But an ancient sage once told me that, contrary to what you'd expect, 'soft wears hard' in engines. Not sure about the absolute truth of that but that adage seems to have held true in a number of cases (old Triumph clutch baskets was the case in point at the time as I recall). If so the teeth on the plates shouldn't in fact be softer but harder.

 

Old sages' tales though, perhaps.