How much clutch wobble is acceptable

nopdog

nopdog

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Went for a 1000 km ride last week, bike ran well except for the following. Clutch has always felt a bit heavy/wobbly/vibey/noisy at 2500 to 3000 revs but fine above 3000 revs. Towards the end of the ride the vibrations etc were felt up towards 4000revs then ok.
On removing the primary cover there is about 3mm of movement in the clutch basket. I can wobble it side to side a few mm. Is this ok?
I’ve pulled it all apart and all seems fine no real wear issues. The peened over studs are solid. I’ll clean the clutch plates as they are a bit sticky etc.
I haven’t checked out the split balance gear spring but have a new one and have Richard 7s tools for the job so will replace.
What are your thoughts and have I missed something and is there anything I should do whilst it’s apart.
Thanks in advance.
Simon
 
nopdog said:
Went for a 1000 km ride last week, bike ran well except for the following. Clutch has always felt a bit heavy/wobbly/vibey/noisy at 2500 to 3000 revs but fine above 3000 revs. Towards the end of the ride the vibrations etc were felt up towards 4000revs then ok.
On removing the primary cover there is about 3mm of movement in the clutch basket. I can wobble it side to side a few mm. Is this ok?
I’ve pulled it all apart and all seems fine no real wear issues. The peened over studs are solid. I’ll clean the clutch plates as they are a bit sticky etc.
I haven’t checked out the split balance gear spring but have a new one and have Richard 7s tools for the job so will replace.
What are your thoughts and have I missed something and is there anything I should do whilst it’s apart.
Thanks in advance.
Simon
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Without measuring mine , I can't say . But I would like to ask you how you are measureing this ? Is this a side to side motion measurement , Or a rocking motion that you are seeing ? The side to side motion I have seen on mine , but 3 mm seems too much. If it were me , I would pull the clutch and source new ball bearings (possibly from Norton UK) . If memory serves , they are retained with circlips. The change in vibration you felt is troubling , so new bearings is what I would do as well.
 
Start with the simple stuff. Check and bleed the system before going to anything in the primary. And with what Tony said. How are you measuring this? The outside basket has some deflection so a little movement isn’t a concern but since the ring gear rides pretty solid you should get that much movement at all. Try to video what you are talking about if you can.
 
The clutch basket movement is side to side it’s not much and the 3mm is just a guess. The bearings appear fine but will further test. It’s all apart at the moment so hard to video. I never thought about bleeding the system but will do it once it’s all back together.
 
I may not be explaining it correctly.
It’s more like when you roll the throttle on at low revs 2500 to 3000 the primary appears to shudder it’s not real noisy but you can feel it through your feet. It disappeared at 3000. This has changed to you can feel it up to 3500 nearly 4000 revs and then it disappears and bike is fine. Hope this helps.
 
nopdog said:
The clutch basket movement is side to side it’s not much and the 3mm is just a guess. The bearings appear fine but will further test. It’s all apart at the moment so hard to video. I never thought about bleeding the system but will do it once it’s all back together.
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OK , So now that it is apart take the opportunity to check out some other things which have been a problem for others in the past. If you look back to the Bushman thread , you can test your balance shaft bearings this way. Essentially remove the oil pump and the balance shaft gear . This will allow you to rotate the balance shaft from either end (oil pump or drive side) . Do this by hand , listen and feel for any noise or roughness. The shaft should revolve smoothly and quietly. Don't forget to check motor mount bolts for tightness and the exhaust system . Can you recall if this was sudden or a gradual change ?
 
It was a gradual change over a few thousand kms.
With the balance gear spring. I’ve read somewhere that the factory stopped lining up the dimple to the stud and would stop and set one tooth short. Mine was set this way. What is acceptable practice line it up with the position stud or one tooth short?
 
I should say it became more noticeable over the last ride 1000km but started a few thousand km ago.
 
@nopdog Do you mean that while mounted on the bike the clutch basket can be slid from side to side slightly (or up and down depending where the engine stopped) while the backplate and gear stays in place? If so the centre of the basket is worn. I found that issue on mine, and drilled out the rivets to investigate. It seems hard to believe it would wear as it only move a few millimetres, but it was. It really needs a wider bronze insert to run on as the back of the basket isn't very thick. Weirdly I found that by rotating the basket 180º from it's original position the play was eliminated. I used M10 countersunk HT nuts & bolts to put it back together and it is quieter than before. I do plan to find an engineering shop to machine out the centre and press in a bronze bush which should be a longer term fix.

If you are replacing the bearings anyway this may be of interest. When replacing mine I hunted and found a 3205 double row angular contact bearing which I fitted in place of the inner bearing. It's only 5.6mm wider than the standard 6205, but you need to adjust the spacer behind the clutch to maintain it's relative position. (These clutches are pretty heavy so any help they can get...)

Besides the fact that a double row can take radial load, these bearings, because of the way they are designed can also take much higher axial loads.

The one I got is a FAG 3205-BD-XL-TVH-L285-C3 Open Double Row Angular Contact Ball Bearing 25x52x20.6mm

I don't think you really need C3 bearings TBH as I don't think the clutch gets hot enough for clearance to be a concern.

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To put this thread to bed here is the outcome. The balance spring was a bit stretched out to 15.5mm I know that’s still within spec but. Got on to Richard Coote and he said that they had never had a problem when the dimple was lined with the stud and wouldn’t comment on what the factory was doing.
So that’s what I did. Reset the new balance spring dimple to stud. Cleaned the clutch plates put it all back together. Checked the engine bolts etc and all was good. It’s holiday season here at the moment so the roads are a little crazy. Took it for about a 10mile spin and fuck me what a transformation. No shuddering at low revs no snatchiness at low revs it will pull with a roll on of the throttle from as low as 2000 in all gears. So thanks for all your help fellows and ride safe.
 
Dimple to stud confuses me, but yeah we did back the preload off one tooth. So instead of the two 8mm holes aligning, it looked like a half moon. Reason being we had some backlash springs failing. I dont know if it was a dodgy batch of springs or something, but that was the new sub-assembly procedure.
 
nopdog said:
To put this thread to bed here is the outcome. The balance spring was a bit stretched out to 15.5mm I know that’s still within spec but. Got on to Richard Coote and he said that they had never had a problem when the dimple was lined with the stud and wouldn’t comment on what the factory was doing.
So that’s what I did. Reset the new balance spring dimple to stud. Cleaned the clutch plates put it all back together. Checked the engine bolts etc and all was good. It’s holiday season here at the moment so the roads are a little crazy. Took it for about a 10mile spin and fuck me what a transformation. No shuddering at low revs no snatchiness at low revs it will pull with a roll on of the throttle from as low as 2000 in all gears. So thanks for all your help fellows and ride safe.
Click to expand...
Hi , Are you still running the balance shaft with the index mark off one tooth with the crank gear mark ? Or back to lined up marks crank gear to balance gear ?
 
The crank gear mark and balance gear mark are lined up. The Cootes manufactured a few tools to set the balance gear spring. It’s available on cnw website as is the procedure/ manual. The manual is a free download. With the tools you can see what the current tension of the balance spring is and reset it etc.
 
nopdog said:
To put this thread to bed here is the outcome. The balance spring was a bit stretched out to 15.5mm I know that’s still within spec but. Got on to Richard Coote and he said that they had never had a problem when the dimple was lined with the stud and wouldn’t comment on what the factory was doing.
So that’s what I did. Reset the new balance spring dimple to stud. Cleaned the clutch plates put it all back together. Checked the engine bolts etc and all was good. It’s holiday season here at the moment so the roads are a little crazy. Took it for about a 10mile spin and fuck me what a transformation. No shuddering at low revs no snatchiness at low revs it will pull with a roll on of the throttle from as low as 2000 in all gears. So thanks for all your help fellows and ride safe.
Click to expand...
Thanks for the update. I'm glad to hear it's fixed, but what actually was the problem then? I cannot imagine cleaning the clutch plates making such a dramatic difference.

I think you are referring to the stud on the @richard-7 alignment tool the Cootes make, which sets the stud to one tooth to the right of the dimple (i.e. less tension)? Which is the same as @Stu Bodycote was doing at the factory.

How much clutch wobble is acceptable


All the best for the New Year.
 
Oops forgot that you turn it over to set the balance spring. My bad and a sign of the times (old age). Didn’t pay too much attention when pulling it apart but the two gears that sandwiched the balance gear spring were out of whack. Not to sure how the balance gears work but the two gear’s weren’t lined up like they were after fitting and setting a new spring.
 
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