Hello Everyone,

My 1943 WM20 has the standard single spring clutch, I have removed the clutch while I replace the Gearbox bushes (leaking oil and even grease from mainshaft bush)

The clutch did not have the Tin hat cover fitted, when I purchased the bike it was not running any oil in the primary case, relying on manual chain lube for the primary chain.

I had since put oil in the primary case and todate have not noticed any ill effect on the clutch, which by the way i don't intend stripping, it was working well before, so I'm taking the, "if it ain't broke don't touch it" approach...

My question is, since I intend to nicely seal the Primary Cases and run oil in them, will I need to locate a Tin Hat cover for the Clutch ?, I imagine its purpose is to keep oil out of the clutch, but maybe it has wet type plates fitted, is that possible ? or was the cover just left of becasue the case was dry so to speak..

email (option): mskehan@komatsu.com.au

The normal Ferodo friction plates in the M20 clutch should not get any oil on them (Same as the clutch in your car).Unlike other types (cork etc) which do require oil on them. Running the case dry with chain lube is OK for short trips, but the oil is also there to add some cooling inside the case. Although others say they have run their bikes with no oil for years. Why not find a bowler hat and do it the way BSA intended? Ron

email (option): ronpier@talk21.com

Hi Mick,
i don`t run oil in my M20, just spray lube, as Ron says ok on short trips,as i don`t really do long rides. I do have the bowler hat and gasket fitted to mine, i agree with Ron, fit what is intended as it is insurance.
I do a few swap meets and I have never seen one, here in Aust. could be hard to find.
I am in Victoria, call me if you wish 03 57216747

cheers Dave

email (option): jamfam@dragnet.com.au

Isn't the primary case oil also needed to lubricate the clutch bearings? And the engine shock-absorber?

email (option): dannydefazio@sumpmagazine.com

Mick
I have a Spare cover in the Shed (it was the only part of the original Clutch in the Box) should you need it give me an Email for the cost of Postage its Yours

email (option): grumpy.moran@gmail.com

It's a good point about the clutch rollers Danny. Although they are only in operation when you pull the clutch lever in, they will still need some lube. Greased on assembly will last some time of course. Ron

email (option): ronpier@talk21.com

Can anyone honestly say that their clutch plates are dry even with the cover on? Just like early Harley Sportsters the cover didn't do anything except keep the oil inside!!

Perhaps Douglas, there is an acceptable level of just how 'wet' the plates can be?

I would think that without a cover of some sort then the plates are going to be saturated and will likely slip. With a cover, then 'Most' of the lubricant will be prevented and plates should hold reasonably well without having to over tighten the springs.

I've had my WM20 clutch down a couple of times and have never found any oil on the plates - certainly not that I've noticed, anyway.

email (option): dannydefazio@sumpmagazine.com

Same for me, always bone-dry, even dusty

email (option): viaconsu "at" planet "dot"nl

Yep! Just stripped my clutch last week and found rust and dust inside the bowler hat. Ron

email (option): ronpier@talk21.com

Thanks Guy's, appreciate all the feed back, and agree better to run lube in the case than dry, I will take the general advice and fit a "hat", will follow up with Ron from down under for the cover, the help on this site is awsome. cheers.

email (option): mskehan@komatsu.com.au