Leakless primary chaincase

donât forget there is a roller race in the clutch that needs some lubrication as well.

Ron makes a good point re. the clutch roller race, and my '57 99 clutch also has the original cork inserts which need a small amount of oil to help prevent them from burning out. Norton always recommended SAE 20, and don't forget that the plug at the bottom is a level plug not a drain plug. I straightened my chaincase out many years ago using a block of wood to support the centre while standing on the case, and I also fit the case by banging round the outer rim with a clenched fist so that it almost home before fitting the large centre nut. Everytime I've removed my case it contains approximately the same amount of oil that I had put in.

Previously wrote:

Ron makes a good point re. the clutch roller race, and my '57 99 clutch also has the original cork inserts which need a small amount of oil to help prevent them from burning out. Norton always recommended SAE 20, and don't forget that the plug at the bottom is a level plug not a drain plug. I straightened my chaincase out many years ago using a block of wood to support the centre while standing on the case, and I also fit the case by banging round the outer rim with a clenched fist so that it almost home before fitting the large centre nut. Everytime I've removed my case it contains approximately the same amount of oil that I had put in.

could you please tell me if there is a rubber seal behind the chrome washer that retains the chaincase 1957 &1962 dommi 99 many thanks kevin nicholls1

Previously wrote:

Previously wrote:

Ron makes a good point re. the clutch roller race, and my '57 99 clutch also has the original cork inserts which need a small amount of oil to help prevent them from burning out. Norton always recommended SAE 20, and don't forget that the plug at the bottom is a level plug not a drain plug. I straightened my chaincase out many years ago using a block of wood to support the centre while standing on the case, and I also fit the case by banging round the outer rim with a clenched fist so that it almost home before fitting the large centre nut. Everytime I've removed my case it contains approximately the same amount of oil that I had put in.

could you please tell me if there is a rubber seal behind the chrome washer that retains the chaincase 1957 &1962 dommi 99 many thanks kevin nicholls1

Hello

the best way is too get your chaincase outer cover straight first, I use silicone sealant for the inside of the rubber band and grease for the outside of the rubber band then when you fit the outer chaincase it is easy to get off , and I use ATF Automatic transmission fluid a 1/4 pint in the chaincase and no leaks? and there is a large rubber washer behind the chaincase where the centre nut fit's, allso you sould have only havetwo threads showing when you do the centre nut up , yours anna j dixon I am only a woman ??

Previously wrote:

Previously wrote:

Previously wrote:

Ron makes a good point re. the clutch roller race, and my '57 99 clutch also has the original cork inserts which need a small amount of oil to help prevent them from burning out. Norton always recommended SAE 20, and don't forget that the plug at the bottom is a level plug not a drain plug. I straightened my chaincase out many years ago using a block of wood to support the centre while standing on the case, and I also fit the case by banging round the outer rim with a clenched fist so that it almost home before fitting the large centre nut. Everytime I've removed my case it contains approximately the same amount of oil that I had put in.

could you please tell me if there is a rubber seal behind the chrome washer that retains the chaincase 1957 &1962 dommi 99 many thanks kevin nicholls1.

I don't think that a rubber seal was fitted but I made one from an old inner-tube. I don't think that it makes any difference to the seal round the foot-rest mount but it stops the metal washer from bearing directly onto a chrome or painted surface. Bob

Previously wrote:

There is going to be more onthis subject in Roadholder No. 271 May/Jun 2010

I bought my 1961 Dominator 3 years ago complete with RGM belt primary drive and Commando diaphragm spring clutch, hence no primary drive lubrication. For various reasons, I haven't done much mileage but acquired panniers this winter to allow longer, one-way journeys. I've been reading the Roadholder correspondence on the subject of the primary chaincase oil leakage with interest but smugness - clearly not my problem! This edition's correspondence has got me worried about what might happen if Istart to use the bike for longer, faster journeys. There appears to be no special arrangement for ventilation of the belt drive, just the standard primary chaincase and I do not know whatclutch bearingis fitted and if it issuitable for working without oil.

All the time I have owned the bike, there has been an odd but very pronounced "whoomp, whoomp" related to road speed and whichI have failed to fix despite renewing rear chain and both wheel bearings. I have begun to suspect it may be coming from the belt drive and/or clutch bearing.

Advice, please before I get marooned somewhere with a failed primary drive.

Nigel Orchard, Salisbury

Hi.

I raised the point there are other components in the chaincase that require lubrication,

My main concern being the roller race in the clutch, my experience is limited to the made up race at the back of my 1961 domi clutch.

This race really only has work to do when the clutch is open, so it duty cycle is quite low, I have been looking at â DRY FILM â PTFE/TEFLON lubricants as a possible Spay On substitute. See. blueworksbrand.com/products/high-performance-ptfe-lubricant

Going a little further, just the rollers are available for my type of race, can these be replaced by a ceramic or other type material that needs no lubrication.

There is also a whole range of high performance â Plastic â bearings, some with steel balls, some 100% ceramic race. These need no lubrication at all.

Come on guys this is the 21st century, we canât be beaten by a leaky tin can!

Ron C.

There is a pad of something or other to separate the steel case from the alloy motor case.I used apiece of leather.Regards John.

On a Dommie chaincase there is actually a large FELT washer behind the chrome securing nut & washer. This makesseal around the footrest shaft. The rubber seal is behind the inspection cover. No other seals are in the Parts Lists but it wouldn't hurt to make a rubber one to go behind the large chrome washer.

The "pad" between the inner chaincase and the alloy crankcase is a standard, thin paper washer/gasket. Always fit a new one if the old one has gasket goo on it.

Cheers, Lionel

I don't know if post war 16Hs differed but the pre-war models shared the various seals with the rest of the range and the wartime WD models.

The 1937 parts book lists the following :-

3417 - Front chaincase rubber seal (that's the obvious one)

3419 - Front chaincase Inspection Disc rubber washer (This was replaced with 3419A - felt as a wartime rubber economy.

3425 - Front chaincase Innner Portion Crankcase Rubber washer (this is a stepped moulding)

3426 - Front Chaincase Inner Portion Gearbox Felt Washer

3427 - Front Chaincase Inner Portion Footrest Tube Felt Washer

Attached is a photo of those which I have (and can identify).

[IMG]http://i248.photobucket.com/albums/gg164/commando16h/NOC/Chaincaseseals.jpg[/IMG]

I've also found it useful to cram a couple of felt washers into the footrest tube aperture. That said, not a lot of oil comes there as the chain is only dipping at the bottom.

Hello Guys I do not have this problem as its all down to the owner of the machine in question .and Yes i have ATF in my primary chain case and not one leak and on silicon sealer ether well I am only female after all ?