Clutch centre rubbers Norton Mercury 1968

I recently tried to fit new rubbers to my 99 and found they were a poor fit being made the wrong shape , don't remember where they came from but happily the old ones were not too bad to go back in.

Hello, Mate, you should if the small rubbers in first then the big ones have you an old gearbox main shaft to fit the spider on, in a good strong vice, I make my own Clatch tools a lotstrong then what you can buy, anyway let hope you get there in the end all my best anna j

I changed my Dommie ones maybe 15 years ago as the book instructs with no problems. But recently tried and failed hopelessy with the 16H. Les tried at Russels without much more success. So I trimmed them a bit and they seem OK.

I think the new ones are either wrong material or wrong size. Someone here suggested filling the gap with silicone RTV. Might be a good idea to grease the gaps first? If I ever do it again, that's what I'm going to try.

Chas... Les got the rubbers into the 16H centre after a huge effort. (My vice at home was not strong enough to grip the spare shaft).

Then when I put it on the bike it wouldn't sit flush so I dismantled the centre just to get the rubbers out. They were obviously not correct. In my case I was lucky as the old ones were just swollen sideways so i trimmed them and put them back. Seems OK so far (small power compared with Dommie?...)

But I think I was lucky the spider didn't bend. I wouldn't fancy using a beefier tool.

I think there's other recent posts on this topic.

Good luck!

The big rubbers need to go in first. They are more compressible than the thin ones. Make sure you put them the correct side, so that they take the drive load! At the top, the fat rubber goes to the right of the spider, and the thin ones to the left. The clutch drum pushes on the spider....

Then use the clutch plate tool to compress them so that you can slide the over-run rubbers in. You may find it easier to use some kind of lubricant, but make sure it's one which is safe with rubber. Bearing grease and mineral oil definitely not OK

Paul

That's the theory Paul. Les at Russels has done lots of them over the years and he couldn't get them in properly so they now seem either to be too stiff or too big. Maybe they are all now coming from a 50 year old box of new old spares?

I bought a lot of OEMNOS clutch parts from an ex Norton Berliner main dealer in the USA and there was a lot of the clutch shock absorber rubbers in with the three boxes of parts. All these rubbers fit perfectlyso your rubbers must be either far too big or not made as per the original Norton design. So much for pattern parts, if they can not make them as per the original why make them at all. I had a special tool made up for turning the clutch centre to fit them and also a main-shaft to hold the centre in place, and they all slide in ok. You can use some sort of grease or washing up liquid to help them go it.