Navigation

You are here: Home / Messages / Singles / 1934 Norton ES2 clutch drag

1934 Norton ES2 clutch drag

Up to Singles

1934 Norton ES2 clutch drag

Posted by leslie_youngman at December 16. 2017

Hi all.

I have just completed the restoration of my 1934 ES2, see pics if I manage to load them.

I have clutch problems with 'swelling' plates I think.

I set the clutch up with correct free play on the cable and it works fine when cold, soon as it warms up slightly the end play increases it starts to drag. If I adjust the cable up it works fine again, but not for long then the same thing happens again. Not sure how far it would go before there is no clutch release at all.

I have a set of new friction plates (painted blue in colour, some of you might have used them) the drive plates are used but good with very little wear and pretty flat. It has the old type chainwheel with new cork inserts.

It does the same dry without outer cover fitted and with the cover fitted and SAE 20 oil in the bath.

Have any of you had any similar experiences?

All advice or suggestions to resolve appreciated.

cheers

Les

Attachments

Re: 1934 Norton ES2 clutch drag

Posted by Ian MacDougall at December 16. 2017

Hi Les

Have you checked that the clutch centre nut is tight? If it is slowly loosening off the whole clutch assy will move outwards, increasing the free play on the cable. Just ask George Phillips about this!

Cheers, Ian McD

Re: 1934 Norton ES2 clutch drag

Posted by ian_allen at December 16. 2017

Hi.

This could be down to wear on the mainshaft bronze thrust washer or the gearbox mainshaft hasn't been shimmed correctly.

First off, check the amount of end-float you have on your mainshaft. I'm assuming all you bearings are in good nick. Remove the clutch, make sure you gearbox sprocket nut is fully tight and push the mainshaft inwards, keep pressure on it and measure the distance with a vernier caliper from the end of the mainshaft to the tip of the sleeve gear. Then pull the mainshaft outwards and measure again. The difference should not be more than 1/32" or  31 thou (the minimum it should be is 8 thou). If it is slightly more than this i.e. 10 thou then it can be shimmed up with a packing washer behind the clutch worm nut pushing the bearing inwards. If it is more then the gearbox will have to come apart. Check the thickness of the bronze thrust washer - it should be 7/32" or 0.219". Maximum permissable wear is 1/16" or 0.0625".  If it is OK then you'll have to add shims to the end of the mainshaft between the bearing and mainshaft first gear and/or the sleeve gear and its bearing. Also, these boxes often had shims behind the large main bearing but they often disintegrate. They also sometimes have a dished shim washer (hence the reason to hold press on the shaft when measuring end float) between the first mainshaft gear and the bearing but these too tend to break or go missing.

Cheers,

Ian.

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at December 16. 2017

Hi Ian, thanks for your response. I have checked the centre nut and it is still tight.

I didn't mention before that's it's not a permanent degradation, when left to cool down the cable has to be released again to get end play and it works fine again, until it warms up of course.

so the problem comes when hot and goes away again when cold again.

Les

 

Previously Ian MacDougall wrote:

Hi Les

Have you checked that the clutch centre nut is tight? If it is slowly loosening off the whole clutch assy will move outwards, increasing the free play on the cable. Just ask George Phillips about this!

Cheers, Ian McD

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at December 16. 2017

Thanks Ian for all that info

I didn't mention before that's it's not a permanent degradation, when left to cool down the cable has to be released again to get end play and it works fine again, until it warms up of course.

so the problem comes when hot and goes away again when cold again.

if it was an end play issue would it not play up whether hot or cold?

Les

 

Previously ian_allen wrote:

Hi.

This could be down to wear on the mainshaft bronze thrust washer or the gearbox mainshaft hasn't been shimmed correctly.

First off, check the amount of end-float you have on your mainshaft. I'm assuming all you bearings are in good nick. Remove the clutch, make sure you gearbox sprocket nut is fully tight and push the mainshaft inwards, keep pressure on it and measure the distance with a vernier caliper from the end of the mainshaft to the tip of the sleeve gear. Then pull the mainshaft outwards and measure again. The difference should not be more than 1/32" or  31 thou (the minimum it should be is 8 thou). If it is slightly more than this i.e. 10 thou then it can be shimmed up with a packing washer behind the clutch worm nut pushing the bearing inwards. If it is more then the gearbox will have to come apart. Check the thickness of the bronze thrust washer - it should be 7/32" or 0.219". Maximum permissable wear is 1/16" or 0.0625".  If it is OK then you'll have to add shims to the end of the mainshaft between the bearing and mainshaft first gear and/or the sleeve gear and its bearing. Also, these boxes often had shims behind the large main bearing but they often disintegrate. They also sometimes have a dished shim washer (hence the reason to hold press on the shaft when measuring end float) between the first mainshaft gear and the bearing but these too tend to break or go missing.

Cheers,

Ian.

Re: 1934 Norton ES2 clutch drag

Posted by ian_allen at December 16. 2017

Hi.

As everything warms up, including the gearbox, then any end float present will increase. If this is excessive your clutch will not fully disengage, start to drag, then the  plates heat up and so forth exacerbating the situation further. The other thing you could try is strapping the clutch lever in and checking the gap under the pressure plate is even. The manual says you should do the pressure plate bolts up fully. On my Manx this results in the pressure plate not lifting evenly. I use feeler gauges under the plate and adjust the bolts. I put a dab of loctite on the bolt threads. Check there are no ridges on the spring cups too. Having said all this, I really would advise checking the gearbox end float first.

Cheers

Ian.

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at December 17. 2017

Thanks Ian

i will have to pull it all apart again to check end float it seems, no shortcuts here...

During assembly I did check the cups and the clutch centre for wear, all looked good.

i have not checked the gap under the pressure plate for even separation but did fit new springs so will definitely do this check, didn't know it needed to be so accurate, my Matchless and AJS clutches all wobble and separate unevenly with no adverse effects.

i am going to do one last experiment before disassembly, going to set the clutch up cold with free play on the cable, then going to run the bike without activating the clutch until already warm/hot to see if the cable free play has increased and by how much. This will tell me how much of the problem is being caused by end float and increase thereof when hot and how much by clutch not fully disengaging and getting hot.

another point to add just for info is that when started in neutral the rear wheel spins unless I operate the brake so there is drag somewhere in the gearbox as well. It's not significant drag, wheel stops easily enough when brake applied with no impact on engine idle.

will let you know what I find

Les

ps what's the trick to getting the primary chaincase cover off, it was pretty difficult to get on with a new seal and would not budge when I tried to pull it off the other day?

Previously ian_allen wrote:

Hi.

As everything warms up, including the gearbox, then any end float present will increase. If this is excessive your clutch will not fully disengage, start to drag, then the  plates heat up and so forth exacerbating the situation further. The other thing you could try is strapping the clutch lever in and checking the gap under the pressure plate is even. The manual says you should do the pressure plate bolts up fully. On my Manx this results in the pressure plate not lifting evenly. I use feeler gauges under the plate and adjust the bolts. I put a dab of loctite on the bolt threads. Check there are no ridges on the spring cups too. Having said all this, I really would advise checking the gearbox end float first.

Cheers

Ian.

Re: 1934 Norton ES2 clutch drag

Posted by ian_allen at December 17. 2017

Hi again.

Try pushing a 12" socket extension bar through the inspection cap hole and gently levering from various angles. When I put my 1960 ES2's case together I always put a smear of RTV along the bottom half with a smear of 'Copaslip' around the top half to help with taking it apart.

Cheers

Ian.

Re: 1934 Norton ES2 clutch drag

Posted by ross_hollands at December 17. 2017

Hi Les,

Try to avoid stopping in gear, i.e. just before you stop, snick the gearbox into neutral, then wait until you are about to take off before you select 1st gear.

This should prevent the clutch plates from generating too much heat.

My 1950s bike with Laydown gearbox and Norton clutch does not like sitting in gear.  The clutch quickly heats up and starts to drag.

If you do cure the problem, I would be very interested in hearing about the solution that you found.

Cheers,

Ross.

Re: 1934 Norton ES2 clutch drag

Posted by ian_soady at December 17. 2017
Previously leslie_youngman wrote:

another point to add just for info is that when started in neutral the rear wheel spins unless I operate the brake so there is drag somewhere in the gearbox as well. It's not significant drag, wheel stops easily enough when brake applied with no impact on engine idle.

will let you know what I find

Les

<

That's fairly normal as it's just the oil in the box dragging the output shaft round. As long as, as you say, it stops with the brake easily without stopping the engine it's nothing to worry about.

Re: 1934 Norton ES2 clutch drag

Posted by Barry Carson at December 17. 2017

Re: 1934 Norton ES2 clutch drag

Posted by robert_tuck at December 17. 2017

A tight chain or even tight spots in the chain will pull the clutch over and make the plates rub the inside of the drum causing drag. My modification with oversize rollers helps to resist this.

Re: 1934 Norton ES2 clutch drag

Posted by ian_soady at December 17. 2017

You always need to finish off adjusting the primary by pushing it forward (ie slightly overtighten then use the adjuster to push the gearbox forward to get the right tension). This is because the pull on the rear chain is more than that on the primary so that tends to pull the gearbox backwards. Finishing the adjustment with pushing the box forward ensures that all the small clearances are taken up.

Re: 1934 Norton ES2 clutch drag

Posted by ian_allen at December 17. 2017

Hi again Les.

This might be useful  sorry about the quality but I had to copy it from a PDF file too large to load on the NOC comments.

Cheers,

Ian.

Attachments

Re: 1934 Norton ES2 clutch drag

Posted by ian_soady at December 17. 2017

That's a very handy little article Ian.

Re: 1934 Norton ES2 clutch drag

Posted by George Phillips at December 17. 2017

Glad you found the clutch retaining nut to be tight. Ian MacDougal is quite right to note it. My IoM trip this year was almost ruined by that nut being just a tad loose. Let us all know what you find to cure it, Les, as it's a common prob. I have to say that since the application of a size 10 boot on the spanner end on the Island I've had no further probs. George

Re: 1934 Norton ES2 clutch drag

Posted by George Phillips at December 17. 2017

A great article, Ian. I notice the date of the magazine was my fifteenth birthday! George

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at December 17. 2017

Thanks Ian, very useful article

Les

 

Previously ian_allen wrote:

Hi again Les.

This might be useful  sorry about the quality but I had to copy it from a PDF file too large to load on the NOC comments.

Cheers,

Ian.

Re: 1934 Norton ES2 clutch drag

Posted by Ian MacDougall at December 17. 2017

Apart from the chain tension and end float suggestions there is another possibility - the plain plates may be distorting as they warm up which will produce drag, although I don't think that alone would account for the increase in free play. I think you mentioned that you haven't replaced the plain ones as they are pretty flat. There may be a world of difference between flat and pretty flat! New plates are thicker than the originals and have a dimpled finish. I think they are less likely to distort.

Cheers, Ian McD

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at December 18. 2017

Hi Ian

Pretty flat is probably not the best choice of words. I have a good set of the new type drive plates with the dimples fitted, these were fitted as replacements for the original thinner types which were in terrible condition. I will double check that they are flat when I pull her apart to do the end float checks.

thanks again for all the info

Best wishes to all for the festive season.

Les

 

Previously Ian MacDougall wrote:

Apart from the chain tension and end float suggestions there is another possibility - the plain plates may be distorting as they warm up which will produce drag, although I don't think that alone would account for the increase in free play. I think you mentioned that you haven't replaced the plain ones as they are pretty flat. There may be a world of difference between flat and pretty flat! New plates are thicker than the originals and have a dimpled finish. I think they are less likely to distort.

Cheers, Ian McD

Re: 1934 Norton ES2 clutch drag

Posted by Andy Marks at December 21. 2017

Hi Leslie

Nice bike!

Both my Norton's can suffer with clutch drag if I use the clutch to much. Lot's of traffic is not kind to them!

The most important thing is to make sure you knock it into neutral as soon as possible when stopping and try to avoid slipping it when in traffic.

I've found ATF to be a good oil to put in primary chaincases, might be worth a try - failing that check the plates as people above have mentioned, and maybe bite the bullet and get some new ones. We had a problem a couple of years ago with a Velocette doing exactly what you describe, changing the plates transformed it and it turned out there was a dodgy batch of plates doing the rounds. The wrong material had been used and was swelling up way to much!

I've got the Surflex ones in my Norton clutches, more expensive but well worth it - it's a lovely clutch once it's set up properly.

Good Luck

Andy

Re: 1934 Norton ES2 clutch drag

Posted by michael_sullivan at December 22. 2017

Leslie:

Nice bike.

Cannot the speedo cable be made shorter or re-routed such to eliminate the large amount of freeplay?

Mike

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at January 07. 2018

Quick update on clutch drag...

I checked the main shaft end float and it is well within spec. Then I checked the drive plates and they look flat when check against each other but when checked on another flat surface it could be seen that they are a little warped.

long story short I decided to get a new set from the club shop and when fitting them I had another idea. I had two cable actuator arms, one from a later upright box. I used spare to make up a shorter arm thereby increasing the clutch rod displacement for a given cable travel.

Clutch now works a treat, haven't used it beyond the drive but did test it for a lot longer than the time it used to take to start binding up before.

Will provide updates once the weather improves and I get it out for a longer test ride.

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at January 07. 2018

Hi, I have since rerouted the cable but it's quite difficult to get it to the speedo on the tank panel. Anybody know exactly what the correct speedo connection should be and cable routing for tank mounted speedo. Mine has 90 Deg speedo input connector.

les

 

Previously michael_sullivan wrote:

Leslie:

Nice bike.

Cannot the speedo cable be made shorter or re-routed such to eliminate the large amount of freeplay?

Mike

Re: 1934 Norton ES2 clutch drag

Posted by David Cooper at January 07. 2018

Les

Regarding speedo cable run: There are some pictures in the thread started by Ian Taylor about 9 below yours on the Singles questions.

I've just realised you say you have a "90 degree input connector" - mine is directly out of the bottom of the instrument.  It has an original manufacturer's date marking so I've so reason to suspect it might not be original.

For what it's worth - and it may be obvious -  I fix the cable to the speedo before lowering the panel down into place and then fix the bottom end.  It's not really practical to lift the panel high enough to disconnect the top if the bottom is still in place.  Maybe someone added a 90 degree adaptor just to make it easier to fit?  Can't you just removed the adaptor?

Re: 1934 Norton ES2 clutch drag

Posted by Ian MacDougall at January 07. 2018

Hi Les

Happy to hear you are making progress with the clutch. Just a couple of other suggestions: If a shorter operating arm has helped free the plates it might be worth checking the nipple-pivot dimension at the handlebar end, it should be 1" for these clutches. If later levers have been fitted it might only be 7/8". Going back to your photos it looks like the clutch cable might be a bit on the short side. Lying in front of the oil tank as it does forces a change in direction as it enters the adjuster at the 'box. It would be more usual for the cable to follow the rear guard then pass behind the oil filler before sweeping round to the top tube.

Cheers, Ian McD

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at January 09. 2018

Thanks David, pics are useful. I have the wrong speedo, mine is a later Smith's with a 90deg connector, which I thought would be needed under the tank panel. I am on the hunt for a more correct earlier Jeager type and now know the cable fitting should come straight down. Not a serious issue for now, will sort one day when I come across a suitable speedo.

cherrs

Les

 

Previously David Cooper wrote:

Les

Regarding speedo cable run: There are some pictures in the thread started by Ian Taylor about 9 below yours on the Singles questions.

I've just realised you say you have a "90 degree input connector" - mine is directly out of the bottom of the instrument.  It has an original manufacturer's date marking so I've so reason to suspect it might not be original.

For what it's worth - and it may be obvious -  I fix the cable to the speedo before lowering the panel down into place and then fix the bottom end.  It's not really practical to lift the panel high enough to disconnect the top if the bottom is still in place.  Maybe someone added a 90 degree adaptor just to make it easier to fit?  Can't you just removed the adaptor?

Re: 1934 Norton ES2 clutch drag

Posted by leslie_youngman at January 09. 2018

Thanks Ian, will check both of these. I think very likely that I have later lever assemblies, I rebuilt it basically as it was when last used in Southern Africa and it does a number of 'slightly non standard' features....

Les

 

Previously Ian MacDougall wrote:

Hi Les

Happy to hear you are making progress with the clutch. Just a couple of other suggestions: If a shorter operating arm has helped free the plates it might be worth checking the nipple-pivot dimension at the handlebar end, it should be 1" for these clutches. If later levers have been fitted it might only be 7/8". Going back to your photos it looks like the clutch cable might be a bit on the short side. Lying in front of the oil tank as it does forces a change in direction as it enters the adjuster at the 'box. It would be more usual for the cable to follow the rear guard then pass behind the oil filler before sweeping round to the top tube.

Cheers, Ian McD

Re: 1934 Norton ES2 clutch drag

Posted by ian_richtsteig at January 10. 2018

Previously David Cooper wrote:

Les

Regarding speedo cable run: There are some pictures in the thread started by Ian Taylor about 9 below yours on the Singles questions.

I've just realised you say you have a "90 degree input connector" - mine is directly out of the bottom of the instrument.  It has an original manufacturer's date marking so I've so reason to suspect it might not be original.

For what it's worth - and it may be obvious -  I fix the cable to the speedo before lowering the panel down into place and then fix the bottom end.  It's not really practical to lift the panel high enough to disconnect the top if the bottom is still in place.  Maybe someone added a 90 degree adaptor just to make it easier to fit?  Can't you just removed the adaptor?

Hi David,

Could you please send me the dimensions of the screws which attach the panel to the tank.    I have searched for a supplier with out luck and it seems I will need to make my own.

Thanks in advance, Ian

Re: 1934 Norton ES2 clutch drag

Posted by paul_standeven at January 10. 2018

I think the problem is in your comment 'old type chainwheel with new cork inserts'

The Norton clutch should have Ferodo friction material inserts in the chainwheel, not cork.  These inserts are manually fitted to each friction plate.  The ones for the chainwheel are thicker than for the ordinary friction plates.

Using cork instead of Ferodo inserts will cause drag

Paul

 

Previously leslie_youngman wrote:

Hi all.

I have just completed the restoration of my 1934 ES2, see pics if I manage to load them.

I have clutch problems with 'swelling' plates I think.

I have a set of new friction plates (painted blue in colour, some of you might have used them) the drive plates are used but good with very little wear and pretty flat. It has the old type chainwheel with new cork inserts.

cheers

Les

Powered by Ploneboard
This is Brio Diazo Plone Theme