Clutch pack too thick?

[lotus54]

late 2015 Explorer. Clutch worked fine.  Gearbox had chewed up kickstart idle gear, so Lewisport swapped out for a good one. (Same size mainshaft bearing). Fits fine of course, but now it is like the clutch pack is too thick. (9.88mm).  I have another gearbox here (not the one that came out) and I measure darn close between ‘bottom’ plate and hub/inner hub. But the ‘fingers’ do not stick out enough from the hub- so when the slave is activated it pushed in fine- until it hits the hub. Lever only moves about halfway. 

Ideas?

 

[konrad]

I'd be curious as to what "darn close" actually measures?  I assume it's the distance I showed measuring via pin gauges here: https://www.ossa-efi.com/home/my-upgrades/clutch-control-ring#h.t2nxiwmfefbq

Somewhat related, I've considered making a test fixture that would restrain the clutch slave piston from moving while the clutch cover removed.  That way I could measure the slave piston travel. 

It would be nice to have X-ray eyes to see what is actually going on behind the cover! 😀

 

 

[lotus54]

1 hour ago, konrad said:

I'd be curious as to what "darn close" actually measures?  I assume it's the distance I showed measuring via pin gauges here: https://www.ossa-efi.com/home/my-upgrades/clutch-control-ring#h.t2nxiwmfefbq

Somewhat related, I've considered making a test fixture that would restrain the clutch slave piston from moving while the clutch cover removed.  That way I could measure the slave piston travel. 

It would be nice to have X-ray eyes to see what is actually going on behind the cover! 😀

 

 

I had not seen this one you did. Good info.  I just measured best I could from the ‘mounting pins’ and bottom plate and the clutch outer hub to plate. The pins down are more difficult to measure accurately, since there is a ridge between plate and base of pin. 

 I will do some more measuring- fitting the clutch pack into the other gearbox and see what I get. I am almost certain the replacement gearbox is a older one than the one that came out- since this is likely one of the last bikes made. F

thanks for the help.

[larro]

Regarding the clutch pack and the way it has to be measured. The metal plates we can measure individually as with the clutch plates but one of the metal plates can not be manipulated and that is the one that is part of the basket ( machined) isn't it. What if there are baskets were the tolerances are out of spec just enough for it to cause problems or make the clutch too thick when it is all bolted into the basket. 

[lotus54]

I measured a new pack and it is about the same- plus that one worked fine in original gearbox. 

 So I suspect the very late gearbox it originally had used a slightly different pressure plate.  Mine measures 7mm thick- it would be interesting to see what earlier ones measure. I could make up some slightly thicker release arms, but that does not really address the root issue at all. 

Now the arms only are about 8.3mm away from the clutch hub, not enough (I was reading your measurments and about half). So I’m sure what is happening is the clutch slave pushes the arms in just fine- but then bottoms on clutch hub and will not fully release. 

I am 3D printing some slightly thicker arms- just for testing. But I think I will likely need a different pressure plate. Xiu has a ventilated one, but no longer avaliable. 

I’m in no huge hurry right now, I have loads of other projects to finish and it has been a bit cold for me to ride.