I wasn't expecting to be bringing the bike back on the ute. I was having a great ride on a top morning until I got to Gloucester and things went pear shaped. The bike lost all drive, it can get all gears but still wont drive, clutch seems to work fine but there is a grinding noise coming from the gearbox when in gear and the wheel is turned , I suspect it could have striped some splines I will check it out tomorrow. I would have liked to have been there to help with the spragg, I'm sure you'll get it all back together with no problems Tom.
I'm lucky to have a wonderful wife that travelled 3 hours in the ute to collect me, while I waited in the air-conditioned comfort of the Gloucester bowling club drinking ales, thanks Kay. What a suck hole I am!  

Not a good look for a K, Yes the project bike Gaz

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And this is what I found, hardly surprising it wouldn't drive!
 

Now to find what's caused it to happen. Clutch plate has no manufactures name on it that I can see and measures 5mm, I fitted it about 5000 km's ago with a new Pressure plate and cover. In recent weeks I had noticed that the clutch cable adjustment had been varying from tight to loose, and I thought that I had a shagged cable! at least I know the cable is fine now. Could it be a result of an unbalanced clutch assembly!  Any Ideas on causes appreciated.

Hi Gaz - your clutch plate splines look shagged! This might have introduced an element of 'impact loading' associated with the normal torsional vibration in the drive train which makes spline lube so critical in these bikes. Will you post some pictures of your gearbox input shaft splines as they are likely to be 'toast' (as TWB says), if my theory is correct...

I would say that the centre has been bent out of square and the continual working has fatigued the metal and eventually cracked it.
Possibly bent on removal or instalation from the gearbox hanging on the splines.

It definitely will have been fatigue related with the initiation point most likely being one of the eight rivets as there is permanent stress in these areas due to the rivets being expanded on installation...

The gearbox input shaft is only what - 25mm long? And that clutch disc material will be spring steel - can't imaging being able to bend it with the weight of the gearbox before the shaft disengages BUT i've lost count of the number of times I've been proved wrong....

rawdonball wrote:Hi Craig - your clutch plate splines look shagged! This might have introduced an element of 'impact loading' associated with the normal torsional vibration in the drive train which makes spline lube so critical in these bikes. Will you post some pictures of your gearbox input shaft splines as they are likely to be 'toast' (as TWB says), if my theory is correct...

The clutch plate was near new 5000 km ago when I fitted it, and it was well lubed. The splines have been damaged from a result off what has caused the fatigue. Just lucky the splines on the gearbox are still good.


 

RicK G wrote:I would say that the centre has been bent out of square and the continual working has fatigued the metal and eventually cracked it.
Possibly bent on removal or instalation from the gearbox hanging on the splines.

You could be right rick, the clutch kit I used when I put the bike together was off a spare parts bike I bought that had a recent new clutch fitted. I find it strange that I can't find a manufactures name on the clutch plate.
I have a good spare clutch plate here that you dropped off for me a few months back that I'll fit and see how it goes.

smithy wrote:

Not a good look for a K, Yes the project bike Gaz

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Feel for you Smithy , not a good finish to the trip. 
I had a similar feeling at Gloucester last week. Clutch spun out during an overtake attempt . 
reminding me I have to do the RMS. Too busy riding any chance I get.
consolation of the ute is no other bike has had as good a view across the Barringtons as you. well done Kay
hope it doesn't hold you up too much. good luck .

Blue Knight wrote:

smithy wrote:

Not a good look for a K, Yes the project bike Gaz

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Feel for you Smithy , not a good finish to the trip. 
I had a similar feeling at Gloucester last week. Clutch spun out during an overtake attempt . 
reminding me I have to do the RMS. Too busy riding any chance I get.
consolation of the ute is no other bike has had as good a view across the Barringtons as you. well done Kay
hope it doesn't hold you up too much. good luck .

Thanks Ed, though sorry to hear your clutch is slipping. It does sound like the seals will need changing in old blue sooner than later.
I've just finished putting it back together this after noon,  I put another clutch plate in and decided to swap out the gearbox for another one that I fitted all new bearings and seals to recently. I'll take it for a run tomorrow and see how it goes.

crikey smithy  that's a totally buggered clutch plate ...what the hell ???!@!!

good luck with the fix mate ...fingers crossed for you

smithy wrote:
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Like a good dog; enjoys a ride home in the ute.

Al

charlie99 wrote:crikey smithy  that's a totally buggered clutch plate ...what the hell ???!@!!

good luck with the fix mate ...fingers crossed for you

Looking at those pictures of the clutch disc splines and the G/box input shaft splines again - my guess is that you definitely got an inferior clutch disc. If you can damage the disc splines to that extent without damaging the male splines with which they mate (easy Rossko!!!) then surely there must be a significant quality differential. It's not a tungsten plated gear box shaft now - is it?

rawdonball wrote:

charlie99 wrote:crikey smithy  that's a totally buggered clutch plate ...what the hell ???!@!!

good luck with the fix mate ...fingers crossed for you

Looking at those pictures of the clutch disc splines and the G/box input shaft splines again - my guess is that you definitely got an inferior clutch disc. If you can damage the disc splines to that extent without damaging the male splines with which they mate (easy Rossko!!!) then surely there must be a significant quality differential. It's not a tungsten plated gear box shaft now - is it?

It's not a tungsten plated gear box shaft now - is it? I wish it was , it's probably not the best pic of the gearbox splines I should have had the camera on a slight angle to show the length of the splines, showing the sharper points.
I've got the bike back together now, and yesterday took it for a 200km test run and all is well. I'm still none the wiser on what caused the problem, but I do suspect inferior quality clutch plate, now it's got a Sach's disc fitted.

You did mention the clutch wasn't brand new. My guess is that it suffered from an unsupported clutch spline lube or when it was being fitted on the previous bike. But its great to be back up and running.

Good to be running again Smithy. It looks like a shonky clutch plate or had been damaged previously somehow. Cheers Tom