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Early clutch issue

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Early clutch issue

Posted by nicholas_reeves at July 13. 2018

I have just rebuilt the clutch on my 1935 Es2.  This was all new plates and springs. The reason I did in the first place was because the clutch wouldn't operate due to the cable and handle bar lever coming right back to the bars. When strppingclutch a found loads of End float and damage to the tangs on the plates. So as said replaced parts and stripped gearbox to take up End float .Well having just gone out to make sure all is ok, within 2 miles the lever gradually came back to the bars again so had no clutch and had to ride home in 2nd gear. I checked the clutch lever on the gearbox and you could literally puff it right up by hand with no resistance at all. So much that the cable nipple came outofthe lever where it is so slack. I also purchased a new pushrod from NOC as it said it was the correct length for the dolls head gearbox but found it to be shorter than my original by about half inch and  so wouldnt  opreate the clutch, so used my original one as it had never been a problem before all this happened.  So my question is Why would this happen all off a sudden In the first place but still be the same after all the above has been done. I am totally baffled by this so need advice. Thanks in advance.

Re: Early clutch issue

Posted by paul_standeven at July 13. 2018

I hope that your clutch plates are the early type with friction plates tags out and plain steel ones tags in.

Have you made certain that the clutch lever arm on the quick thread is tight enough?  If the arm slips, you will lose the clutch lift.  It does need to be tight.  Use a ring spanner which has minimal offset, and is as near flat as possible

When I set mine up on my horizontal box, I make sure the cable is happy, that the lifter arm is as far downward as possible, put a screwdriver in the slot in the end of the quick thread and twist clockwise, and with my third hand, tighten the nut on the lifter arm.  Don't forget to do it up good and tight......

Actually, on a Doll's Head box the job  is much easier because the clutch lifter mechanism is exposed

The Norton clutch is a strong unit, able to cope with 50 bhp from the Atlas, and with fewer plates, the Manx....

Paul

Re: Early clutch issue

Posted by david_cooper at July 13. 2018

I had problems with the lever turning on its shaft. Solved by removing it and running a hacksaw through the slot. It was not gripping. No problem since.

Re: Early clutch issue

Posted by ian_macdougall at July 13. 2018

Would also be worth checking the clutch centre nut in case that is coming loose and allowing the clutch assembly to drift outwards.

Ian McD

Re: Early clutch issue

Posted by george_phillips at July 13. 2018

Oh no - not the clutch centre nut again!!

George

Re: Early clutch issue

Posted by nicholas_reeves at July 13. 2018

Previously paul_standeven wrote:

I hope that your clutch plates are the early type with friction plates tags out and plain steel ones tags in.

Have you made certain that the clutch lever arm on the quick thread is tight enough?  If the arm slips, you will lose the clutch lift.  It does need to be tight.  Use a ring spanner which has minimal offset, and is as near flat as possible

When I set mine up on my horizontal box, I make sure the cable is happy, that the lifter arm is as far downward as possible, put a screwdriver in the slot in the end of the quick thread and twist clockwise, and with my third hand, tighten the nut on the lifter arm.  Don't forget to do it up good and tight......

Actually, on a Doll's Head box the job  is much easier because the clutch lifter mechanism is exposed

The Norton clutch is a strong unit, able to cope with 50 bhp from the Atlas, and with fewer plates, the Manx....

Paul

Thanks for your reply Paul. Yes the plates are correct and the clutch arm is tight. The problem seems that when you lift the clutch arm by hand ie cable not attached , it can be lifted to the top of its movement but with no resistance at all. In other words it seems that the worm is moving in to push on the push rod but doesn't reach it. If that makes sense. As the clutch lifter arm is so easy to move. But as mentioned it was OK for 2 miles but not now. Any more thoughts would be helpful as this doesn't make sense at all to me.

Re: Early clutch issue

Posted by nicholas_reeves at July 13. 2018

Previously Ian MacDougall wrote:

Would also be worth checking the clutch centre nut in case that is coming loose and allowing the clutch assembly to drift outwards.

Ian McD

Thanks Ian bit nut is definitely tight. Please read comment I left for Paul. Any more thoughts would be good as completely baffled.

Re: Early clutch issue

Posted by george_phillips at July 13. 2018

How is the thrust washer in the gear box? Is it worn?

G

Re: Early clutch issue

Posted by george_phillips at July 13. 2018

Nicholas - I know you say the clutch retaining nut is tight but Ian has a point (as I know to my cost). It is easy enough to check the clutch retaining nut. The symptoms you describe have all the elements of a loose nut. At least it will remove it for the suspects list.

G

Re: Early clutch issue

Posted by paul_standeven at July 13. 2018

Your reply makes it sound as though the quick thread needs to be re-adjusted, to eliminate lost movement.

Have you tried loosening the clutch lifter arm on the quick thread, use a screw-driver to drive it in as far as it can go so that there is no free play, and then re-set the lifter arm in a low position and tighten the lifter arm nut.

Paul

 

Previously nicholas_reeves wrote:

Thanks for your reply Paul. Yes the plates are correct and the clutch arm is tight. The problem seems that when you lift the clutch arm by hand ie cable not attached , it can be lifted to the top of its movement but with no resistance at all. In other words it seems that the worm is moving in to push on the push rod but doesn't reach it. If that makes sense. As the clutch lifter arm is so easy to move. But as mentioned it was OK for 2 miles but not now. Any more thoughts would be helpful as this doesn't make sense at all to me.

Re: Early clutch issue

Posted by nicholas_reeves at July 14. 2018

Previously George Phillips wrote:

How is the thrust washer in the gear box? Is it worn?

G

Hi George, no that has been replaced when I replaced clutch plates etc.

Re: Early clutch issue

Posted by nicholas_reeves at July 14. 2018

Previously paul_standeven wrote:

Your reply makes it sound as though the quick thread needs to be re-adjusted, to eliminate lost movement.

Have you tried loosening the clutch lifter arm on the quick thread, use a screw-driver to drive it in as far as it can go so that there is no free play, and then re-set the lifter arm in a low position and tighten the lifter arm nut.

Paul

Hi Paul, thanks again for your input. Yes I have done that. But if you think about it, like I didn't before I did it, if the worm is right in , and the lever set low there will be no movement left on the worm when pulling clutch lever on handlebar in. It feels exactly as if there is no pushrod in the clutch at all. But the push rod is the same length its always been when I have done 4000 odd miles with no problems.

Previously nicholas_reeves wrote:

Thanks for your reply Paul. Yes the plates are correct and the clutch arm is tight. The problem seems that when you lift the clutch arm by hand ie cable not attached , it can be lifted to the top of its movement but with no resistance at all. In other words it seems that the worm is moving in to push on the push rod but doesn't reach it. If that makes sense. As the clutch lifter arm is so easy to move. But as mentioned it was OK for 2 miles but not now. Any more thoughts would be helpful as this doesn't make sense at all to me.

I

Re: Early clutch issue

Posted by nicholas_reeves at July 14. 2018

Previously George Phillips wrote:

Nicholas - I know you say the clutch retaining nut is tight but Ian has a point (as I know to my cost). It is easy enough to check the clutch retaining nut. The symptoms you describe have all the elements of a loose nut. At least it will remove it for the suspects list.

G

George, when this first happened before replacing clutch parts etc, I thought the same as I had been reading all your posts on the subject. So after stripping it all down I was surprised this wasn't the problem as it was tight. Remember I have literally only done 2 miles after this rebuild for the Same thing to happen again. If anything the clutch nut is tighter than it was and I also put blue locktite on it to make sure. So annoyed at this as it has been of the road for about 6 weeks due to sorting out all the parts etc. Hate not riding it especially as summer is drifting away.

Re: Early clutch issue

Posted by barry_carson at July 14. 2018

Hello,  if everything else is ok theres only the cable left . apart from the clutch pressure plate and thrust pin. are they ok

 

Barry

Re: Early clutch issue

Posted by david_cooper at July 14. 2018

It seems unlikely but has the push rod lost its hardening on the tips and wearing away?  Not likely in  miles I suppose but a short rod might cause issues after a short mileage because there is some extra lost motion when the alloy box warms up.  So if the take up is marginal when cold it might be lost when hot.

Some owners put a small ball bearing at the end of the rod to reduce oil running along it (or something like that...).  Maybe the PO did this and shortened the original rod (or the mushroom stem)?  Again, without the ball there might be enough motion to lift it when cold but not when hot.

Re: Early clutch issue

Posted by richard_cornish at July 14. 2018

Hi Nick,

   You should always try and fit a 1/4" (6mm will do) ball bearing between the mushroom and push-rod as this stops the mushroom trying to pick up and spin the push-rod. If you have tried all the obvious you might need to strip the clutch again. What can happen is the plain plates can get stuck on the hub where the inner tabs slide against the hub slots. Make sure all the edges are free from burs or grooves and each plate slides freely. Don't be afraid to grease these parts as although some may get thrown onto the plates, it's not normally a problem.

Regards,  Richard.

Re: Early clutch issue

Posted by ian_soady at July 14. 2018

Many years ago I had a pushrod lose its hardening on the end and it was astonishing just how quickly I lost all movement.

I ended up chopping a bit off a 2BA screw (sitting beside the kerb on the Derby ring road) and using that as a spacer which was enough to get me back to Brum.

Re: Early clutch issue

Posted by nicholas_reeves at August 08. 2018

I would just like to update everyone who was kind enough to give invaluable help and advice. I have found out that the push rod was wearing so quickly it was loosing all adjustment within a couple of miles. Just as Ian Soady had suggested. It was the last thing I thought it could be. On closser inspection I found that the clutch end was burred making its removal quite difficult. At least all sorted and a valuable lesson learnt, expect the unexpected.  Many thanks again to one and all. Regards. Nick.

Re: Early clutch issue

Posted by george_phillips at August 09. 2018

Well done Nick and thanks for sharing the info with us.

That's another another little quirk for the memory bank.

George

Re: Early clutch issue

Posted by nicholas_reeves at August 10. 2018

Previously George Phillips wrote:

Well done Nick and thanks for sharing the info with us.

That's another another little quirk for the memory bank.

George

Thanks George, been riding it a fair bit over last week or 2. Hate not having it on the road. Fingers crossed something else doesn't go wrong.Hope yours is plonking away ok. Nick.

Re: Early clutch issue

Posted by jonathan_newton at August 10. 2018

Previously nicholas_reeves wrote:

I would just like to update everyone who was kind enough to give invaluable help and advice. I have found out that the push rod was wearing so quickly it was loosing all adjustment within a couple of miles. Just as Ian Soady had suggested. It was the last thing I thought it could be. On closser inspection I found that the clutch end was burred making its removal quite difficult. At least all sorted and a valuable lesson learnt, expect the unexpected.  Many thanks again to one and all. Regards. Nick.

Nick is it possible you have the adjustment up too tight if its wearing the rod end?  There should be some free play in the  release mechanism or it will continualy be engaged and rotate with very little lube around. Also the rod should be able to rotate freely in the shaft when not active. 

I know we all look for every thou on clutch release movement but  one  tip I had from George C was the lever fulcrum on a twin was shorter than on a lever for a single 7/8" verses 1" .   He would often redrill levers to get the best mecahnical advantage,  Trust you are all fixed up now.

 

Best regards

Jon

Re: Early clutch issue

Posted by ian_soady at August 10. 2018

When it happened to me I was running a special consisting of an ES2 engine / gearbox in an Enfield frame. As the Enfield engine / box were shorter than the Norton items, the constructor of the bike (not me) had dispensed with a primary chaincase and merely had an outer covering the works. This did mean the primary chain was in a right state and the clutch had also suffered so adjustment was always a problem. I eventually rebuilt the power train into a rigid Norton frame and it made a very nice bike.

The point re lever pivot distances is well made. You can normally get 7/8" and 1 1/16" items - the former gives an easy action but reduces the throw. 7/8" levers are good for front brakes as they give extra leverage.

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