Dolls head gearbox quadrant cork washer

That's hopeless, isn't it ? It should indeed fit on the outside and fill the space entirely.

You could try soaking in oil first to see if it expands - but it looks to be composite cork and rubber and may not respond to that treatment - otherwise try making your own from a large cork.

It should stand proud and form a face seal against the large retaining washer. If it doesn't fill the counterbore, it will simply deform.

An 'O' ring may work initially but will flatten and harden whereas a cork washer that remains oily (and it will !) should keep swelling and maintain a light pressure behind the retainer.

I have successfully used an O ring here but you could also use a fibre washer under the cork seal to space it out.

Two things worth considering.

First, is the bush (available as an off the shelf item from one of the on-line bearing suppliers) inserted to the correct depth. This would influence the pressure on the seal.

Secondly, and this was the case on my bike, I found that the oil was leaking up the spline of the shaft through the lever and under the head of the bolt. A little bit of silicon under the washer and bolt head before assembly and no more oil leaks.

Aled

Wrong material, wrong size!

the correct seal as originally fitted by Norton to Dolls Head and the later upright box is made from felt, which you pre-load with grease, both to fit it, and to act as a seal.

The original seal is about 1/2" deep, and with a wall thickness of around 1/8" thick. I got a stock of 1/8" and 1/4" thick felt, and a big set of hole punches, from a firm that sells all sorts of gasket materials, petrol pipe etc, who are always at Stafford, and other major shows, including car. Unfortunately I can't remember their name, but I am sure they were from Liverpool. If you get some 1/8" felt, you could roll a 'tube' to make a suitable seal, especially if you cut the join at a diagonal, or punch cut two 1/4" thick round seals.

There is also a seal made from 1/4" thick felt that goes under the outer cover of the clutch operating worm.

both these seals are clearly shown on pages 47 and 50 of the Norton spare parts list for Models 1, 16H, 18 and ES2 plus 30,40 and Manx, 1946 to 49.

You could also try Russell Motors to see if they have any old stock, but I do remember Les telling me sometime ago that there was a fire in their warehouse, and all the lightweight bits such as these seals got washed away by the fire hoses!

Roger

Roger, are you referring to the ratchet plate cam spindle felt washer at the rear of the positive stop mechanism ? Aled's photo looks to me to be of the quadrant spindle / bush on the lower front of the shell.

I can't find a seal listed in the Spare Parts Lists for that location but the WD M&I Manual states :-

"The cam plate quadrant works in a phosphor bronze bush....the outside of the boss carrying the bush is recessed to take a pressed cork oil retaining washer"

Certainly the old boxes that I've looked at have cork there but I would never rule out that wartime practice differed.

It's the felt tube at the back of the doll's head - there is no oil up there so it only acts as a grease retainer and to keep the muck out. Quite often they can be re-used.

Sorry gents, red face time, I gave out information for the wrong splined shaft, and not helped by being away from here for a few days to post a correction.

The info I gave is correct for the splined shaft of the ratchet plate at the top of the gearbox, not the cam plate quadrant at the bottom of the gearbox.

I've just had a look in my dolls-head gearbox stock at an original gear case, which still had the old seal, which is indeed cork, but the problem with the RGM cork washer in Aled's picture is that it is not thick or deep enough to do the job. As Richard said, it needs to fill up all of the available space between the bush and alloy casing, and also to be slightly proud of the alloy casing so the cam plate quadrant lever presses against the cork, to form a seal.

Also, as Colin said, a dab of silicone under the plate washer stops oil that comes along the splines from leaking out.

If it is any help, the dimensions of the compressed cork washer I took out of the gearbox is 1-1/8" overall diameter, 13/16" inside diameter, and a thickness of 3/16", but you would probably need 1/4" thick from new to allow for compression to seal. Anything less would leak.

The washer is also listed and shown in the 46-49 spares list mentioned above.

Although not running yet, I found in my 1947 upright gearbox that is no sense to fit an external sealing washer, so, I made a pair of cork washers, fitted then inside of the gearbox, sitting tight both at the shafts and against the inner gearbox wall.

Also, the cork thickness allowed the gears meshing face to face and not stepped as without the cork washers.

Attached the pair of shafts with it respective cork washers before fitted to the gearbox.

Hope this help.

Hans in Chile.