Oily Clutch Shoes, What's the connection?

I know this type of problem is discussed elsewhere on the forum and I've been through all the scenarios without success. I brought this over from the 'Belt Squeal' topic because it's not the noise that's got me concerned, it's the cause.

Basically, I'm getting clutch noise at take off and crawling. After numerous investigations, clean ups and test rides I found the clutch shoes looking like this:



This was after about 100 miles of riding since the previous clean up.

I found some other shoes in the garage which are low mileage, I bought them from new a while ago and ran them in a badly scored clutch drum but that's another story.....anyhow, I gave 'em a good rub down and also decided to rub the clutch drum with fine wet and dry paper. I made quite a big difference to the sheen. I put it all back together (without the covers) and ran the engine for about 30 seconds to check the belt and pulleys were behaving. Out of curiosity, I took the clutch assembly off again and the shoes looked like this: (Ignore the groove in the pads, I can't see the connection between that and my problem).



What's going on? I confess the clutch drum isn't in the best of nick but I've seen worse. How can the clutch shoes be collecting that much grease so quickly?

BTW, here are some pics of the clutch drum:





So, what's the connection?

There's an oil seal in the clutch assembly that keeps any grease migrating from the 'torque controller' in the hub along the drive shaft and onto the shoes. It could possibly be damaged.

I'm not sure where you mean. Does it sit on top of the needle bearing?

It's item 21 on this diagram, there's grease in the sliding (twisting) centre of the hub

Mmmmm....you've got me thinking. I've got a dismantled clutch assembly in the garage. I'm gonna see how it all fits together and see if this could be the problem. I'll post my findings.....

https://youtu.be/_IPTRrVtD-8

Don't know if you've seen this, from 10 mins onwards.

There is two possibilities.

Too much grease inside clutch driven face or needle bearing oilseal is damaged.

If oilseal is damaged, you must replace this...

https://www.cmsnl.com/products/brg-ndl27x36x23_91101mct003/

I see only one way to get rid of squeal---new clutch bell, new shoes,, replace seal. These bikes are getting old and the correct new parts can work miracles.

Thanks for all those replies everyone, it gives a good insight into what's going on in there. I get the feeling that a deep investigation is required but I don't want to take the bike off the road right now. Buying new parts would be great and overhauling the assembly a great project, something for the future I think. That needle bearing seal is a likely culprit, however.....

I'm still mystified as to how so much contamination can appear after 30 seconds of running. The hub is stone cold so the grease wouldn't have a chance to melt down and creep into the drum even if the seals were worn....surely? There are no traces of grease movement anywhere.

Is the grease impregnated into the clutch drum? is it possible?

A suggestion; the action of pushing the pulley assembly onto the shaft, if the seal is damaged, could force grease towards the drum and the centrifugal force throws the grease on to shoes. Another suggestion; the first suggestion could be totally wrong.

Well Lenny, I'm thinking along the same lines but I don't think there's enough grease around there to actually 'squelch' grease into the drum area but it's possible.

My first job will be to look in that area and replace the needle bearing for starters.

Are you sure that is grease-oil on shoes. ? Shoes are scuffing on drum and showing high spots after 100 miles. There are 2 # 21 seals on rear hub. I had that all apart last year and bearing with seal is hard to remove. Need an expandable puller and a slide hammer to pull it, press to replace. Outer bearing is even more of a pain had to modify a double pivot needle plyers to remove the snap ring to remove it.

To remove outer face you must compress collar on spring remove snap ring. Not a lot of pressure on spring but you won't be able to do it without a press or some kind of tool. Not much grease in there a few ounces at most but I'm sure it's worn at pins-rollers # 2-3 in parts diagram. Takes a special grease in there ? who knows . I used so Yamaha Polyurea grease. Green and tacky stuff hard to find might be other similar grease over there.

Search here have several photos of drive parts removed in post last year. I lost those photos somehow.

FFFFF I can't find my old post on rear hub. Search engine is difficult here.

Check Dimond’s “Driven Pulley Assembly Rebuild” topic. Mech 1 twa I found your posts and photos very helpful in that topic.

Tim

https://www.silverwing600.com/t7766-driven-pulley-assembly-rebuild?highlight=Druven+pulley+assembly+rebuild

Lenny, that was a great video ,got to love Italian mechanics. One thing I would have done a differently is to sand down clutch shoes first then blow away dust with compressed air followed by dismantling to keep as much dust away as possible. Just a thought.

Yeah, that's a lot of dust. It's always a good idea to 'plug' both ends of the shaft to keep nasties out.

Having said that, that guy's videos are excellent. I've learned a lot from watching them.

Well, I'm off for a 4 day trip to Dorset and beyond on Monday. Fingers crossed for a squeal-free journey. We'll see what the clutch looks like after that!