C: Clutch Twin Clutch Drag

D

delboy

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A weirdo one I had once was, I thought I had checked through absolutely everything until I only had C20 nut and C3 carrier on the shaft.
I rigged up a dial gauge on the OD of C3 and lo and behold, when C20 was tightened, the body of C3 moved many thou's out of concentric and hence there was much interference twixt C3 and PD22/24 bushes of PD20 Clutch sprocket.
Why C3 behaved as such, I know not. So trust nothing!
I put it down to slack splines inside C3 as a new one cured the problem entirely.
Regards, Delboy
 
T

timetraveller

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Hi Paw, I'm not sure what I am seeing on your video but the needle roller thrust races I provide have a hexagon on the outer end of the kit to match that on the original C26. Either it is hidden on yours or there is something there that is not part of my kit. Just wondering?
 
P

paw99

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timetraveller said:
Hi Paw, I'm not sure what I am seeing on your video but the needle roller thrust races I provide have a hexagon on the outer end of the kit to match that on the original C26. Either it is hidden on yours or there is something there that is not part of my kit. Just wondering?
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Hi TT,
I came to suspect that the clutch was not centralising when pushrod force applied, and this video is my amateur way of trying to observe shoes while applying force to plate carrier C13. I have previously seen that drag occurs even when pilot plate is free to rattle, so concluded that failure to centralise is due to friction in C20. Video shows C13 free to move shoes in and out with no end force, but not centralising fully with end force.
Your roller race not used for this test to save it from harm.
I also suspect uneven plate lifting may be partly due to runout on C20 nut and thus its flange being slightly wonky.
Your lifting device, I found some radial play between rod and internal diameter, so put a 2 thou shim round the rod with the loctite.
My next step is to polish C20 (new), lubricate it, increase C13 end play, and anything else I can think of to avoid Mainshaft replacement.
 
bmetcalf

bmetcalf

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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.
 
P

paw99

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delboy said:
A weirdo one I had once was, I thought I had checked through absolutely everything until I only had C20 nut and C3 carrier on the shaft.
I rigged up a dial gauge on the OD of C3 and lo and behold, when C20 was tightened, the body of C3 moved many thou's out of concentric and hence there was much interference twixt C3 and PD22/24 bushes of PD20 Clutch sprocket.
Why C3 behaved as such, I know not. So trust nothing!
I put it down to slack splines inside C3 as a new one cured the problem entirely.
Regards, Delboy
Click to expand...
Thanks Del,
That's helpful, but which face of C3 did you measure, and was it axial or radial wonky? My problem only seems to be there when clutch pressed, and so I did not suspect C3. But I will check.
Cheers.
 
Bill Thomas

Bill Thomas

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I don't think it's your trouble, But the big Chain Wheel also has to have some end float and also spin free,
I fitted new bushes and the oil seal, And one of the bushes was much too thick !,
I had one of my feelings !, So didn't get caught out that time !.
Cheers Bill.
 
D

delboy

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Sorry, Not sure I can describe it any clearer than C3 moving out of concentric on the mainshaft?
It was clocked where the sprocket bushes would run.
When the nut was tightened C3 physically shifted to one side settling in it's own happy place.
regards, Delboy.
 
B

BigEd

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VOC Forum Moderator
greg brillus said:
.......When rebuilding these clutches, it is important to Not make all the tollerances too tight, as this will cause grab within the moving parts.......Good luck with it.
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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.
 
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