C: Clutch Twin Clutch Drag

paw99

Well Known and Active Forum User
VOC Member
Judicious lubrication of the pivoting surfaces is good. A friend took oil-free/dry too seriously and had problems with his clutch until he lubed it.
Ta, will try.
Ch de
Spot on Greg. We like to do as good a job as we can on clearances but too tight tolerances here creates a problematic clutch. I've built mine with lots of old parts so there is quite good clearance almost everywhere and it works fine.
Oh dear, months to make it worse! By fitting new bushes etc..
What next? A bit of gentle lube and hope.
 

paw99

Well Known and Active Forum User
VOC Member
Not too much , or you will be back to square one :) .
Yep , it looks like I've painted myself into a corner, and either need to remove mainshaft runout or increase clearance on (new) C17!
My recent thinking is that C17 is jammed by pushrod force transferred to C13. Can I still find the old C17 in shed? Wish me luck.
Peter
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Peter , I just use wet and dry paper,
Should have seen how much I had to take off the chain wheel bush !,
Vincent stuff often has to me trimmed , No two the same,
On in my case , A lot is still 1950 bits !,
Good Luck, Bill.
 

greg brillus

Well Known and Active Forum User
VOC Member
I recently had my clutch/primary apart to fix a minor oil leak from the primary cover........the clutch had been working perfectly so no issue there........But upon reassembly, I tightened the C20 nut with my 1/2 inch rattle gun and i'm sure it tightened to the next slot on the nut........This after full assembly of the clutch, showed the symptom described where the outer plate was free and 'Clunking up and down" but the kickstart was difficult to push down freely......... This assembly actually had no shims under the C20 nut........ I removed the nut and took a light shave off the inner flange face in the lathe........maybe 10 thou at most, probably 5, then I polished the smooth surface of the nut, and smeared a very, very light amount of engine oil inside the C 17 bush........reaasembled, and now it is free and releasing fine........The C 20 nut needs to be tight or else the C3 will start moving on the mainshaft spline and this will cause further problems down the track.......be careful lubing the parts, as with heat and centrifugal force it will throw out into the drum causing possible slipage. I use a tiny amount of antisieze on the C5/1 shoe pivot pins, as these wear quite badly after much use.......Cheers and good luck to one and all.......
 

paw99

Well Known and Active Forum User
VOC Member
I recently had my clutch/primary apart to fix a minor oil leak from the primary cover........the clutch had been working perfectly so no issue there........But upon reassembly, I tightened the C20 nut with my 1/2 inch rattle gun and i'm sure it tightened to the next slot on the nut........This after full assembly of the clutch, showed the symptom described where the outer plate was free and 'Clunking up and down" but the kickstart was difficult to push down freely......... This assembly actually had no shims under the C20 nut........ I removed the nut and took a light shave off the inner flange face in the lathe........maybe 10 thou at most, probably 5, then I polished the smooth surface of the nut, and smeared a very, very light amount of engine oil inside the C 17 bush........reaasembled, and now it is free and releasing fine........The C 20 nut needs to be tight or else the C3 will start moving on the mainshaft spline and this will cause further problems down the track.......be careful lubing the parts, as with heat and centrifugal force it will throw out into the drum causing possible slipage. I use a tiny amount of antisieze on the C5/1 shoe pivot pins, as these wear quite badly after much use.......Cheers and good luck to one and all.......
Thanks Greg ,
My next move will be to oil C17 gently and try more/ less end play.
 

sharkey

Forum User
VOC Member
Hi sharkey ,
I now have that symptom.
Have you resolved it, and if so how.
If not, you may be interested in my journey to a current tentative diagnosis of clutch shaft runout.
Cheers, Peter
Hi Peter,
Sorry for the slow response although I see you have had some good advice above and there is probably more earlier in the thread.
Having exhausted/checked all of them my issue was cured by replacing C17 which had been a poor fit on C20 allowing the clutch shoe carrier to tilt and thereby engage the drum. The new fit was as perfect as you could hope for; a very smooth slide with no observable play. Polish C20 as Greg Brillus writes above; I also applied to C20 a very light smear of ZX1 grease on assembly.
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Can you tell us where you get the ZX1 Grease ?,
I have been looking for some a long time,
Since Trev told us about it,
Cheers Bill.
 

paw99

Well Known and Active Forum User
VOC Member
Hi Peter,
Sorry for the slow response although I see you have had some good advice above and there is probably more earlier in the thread.
Having exhausted/checked all of them my issue was cured by replacing C17 which had been a poor fit on C20 allowing the clutch shoe carrier to tilt and thereby engage the drum. The new fit was as perfect as you could hope for; a very smooth slide with no observable play. Polish C20 as Greg Brillus writes above; I also applied to C20 a very light smear of ZX1 grease on assembly.
Hi Sharkey, thanks to you and all gor jelpful ideas. I now saw (should have done weeks ago) marks on rear of clutch shoes on plunger housings and on rear edge of plare carrier that show contact , which may be my problem all along. Now to check the theory and how to fix it, then I may be back to report success! I now have a spring in my step, hope to soon have joy in my heart!
On a side note, is it good to put grease rather than oil on a self lubricating C17?
Cheers
Peter
 

Attachments

  • IMG20220130101304.jpg
    IMG20220130101304.jpg
    315.7 KB · Views: 31
  • IMG20220130101334.jpg
    IMG20220130101334.jpg
    232.7 KB · Views: 32
  • IMG20220130101227.jpg
    IMG20220130101227.jpg
    287 KB · Views: 31
Top