16H Dolls Head gearbox mainshaft dished washer

Hi Paul, I spent a while getting the end float within tolerance with new shims etc on my Dollhead box.Even then I still had to move the bearing out from the kickstart side and put a washer behind it.

Russell Motors 020 7228 1714 were very good and Les would go off and search the warehouse for parts to help me out. Also Stu Rogers 01945 585116 was getting shims made and helpful with kickstart shaft fibre gasket etc, which people seem to forget about then wonder why it leaks there.

Hope this helps

I'm not convinced that this washer was always fitted - I can't find it in the wartime parts book but it does indeed appear in the exploded view of the WD workshop manual. My pre-war gearbox definitely didn't have space for it...but I can't explain which parts were changed on later boxes to allow it to fit.

Hi there - I've just finished overhauling the Dollshead Gbox on 1935 Model 50. The gears / dogs, selector forks & camplate were in exceptionally good condition, almost as tho someone had replaced not so long ago. However all the bearings / bronze bushes were shot so I had to replace. I bought ball / roller races & sleeve gear rollers from Simply Bearings - here https://simplybearings.co.uk/shop/index.php - an excellent by-return service. The bronze bushes came from both Mick Hemmings & Norvil since neither seemed able to supply all of them.

Now to the shims (none shown my parts / instruction books) for the main shaft - a big 20 thou one came from here http://racingnorton.co.uk/shop/article_0405%2520A2%252F324S/Norton-Gearbox-Mainshaft-End-Shim.html?sessid=hRs93LrqwMVoiceY79ArEBPJRGnRJq7zJP0wERidU4eR58p2Xp0MrBFEDMFDarcN&shop_param=cid%3D44%26aid%3D0405%2520A2%252F324S%26

with a range of thinner shims from here - http://www.calebcomp.co.uk/products/shims_supportwashers.html

I ended up with 25 thou of shim (same as came out which were mangled) to give me about 12 thou free play. Obviously the thickness of the paper gasket plays a part here. The layshaft didn't need shimming - having 10 thou free play.

Finally I cheated when it came to the cork oil seals on kick start & cam operating arm - I substituted Viton 'O' rings from here - http://simplybearings.co.uk/shop/o_rings.php The size range is so extensive you'll no trouble finding what you want.

Now the proof of the pudding. Gear changing is very positive & smooth when I spin the rear wheel or clutch drum but a road test will have to wait better weather. Fingers crossed.

I hope the above may be of help to anyone else who has to undertake such an overhaul.

Previously wrote:

Hi there - I've just finished overhauling the Dollshead Gbox on 1935 Model 50. The gears / dogs, selector forks & camplate were in exceptionally good condition, almost as tho someone had replaced not so long ago. However all the bearings / bronze bushes were shot so I had to replace. I bought ball / roller races & sleeve gear rollers from Simply Bearings - here https://simplybearings.co.uk/shop/index.php - an excellent by-return service. The bronze bushes came from both Mick Hemmings & Norvil since neither seemed able to supply all of them.

Now to the shims (none shown my parts / instruction books) for the main shaft - a big 20 thou one came from here http://racingnorton.co.uk/shop/article_0405%2520A2%252F324S/Norton-Gearbox-Mainshaft-End-Shim.html?sessid=hRs93LrqwMVoiceY79ArEBPJRGnRJq7zJP0wERidU4eR58p2Xp0MrBFEDMFDarcN&shop_param=cid%3D44%26aid%3D0405%2520A2%252F324S%26

with a range of thinner shims from here - http://www.calebcomp.co.uk/products/shims_supportwashers.html

I ended up with 25 thou of shim (same as came out which were mangled) to give me about 12 thou free play. Obviously the thickness of the paper gasket plays a part here. The layshaft didn't need shimming - having 10 thou free play.

Finally I cheated when it came to the cork oil seals on kick start & cam operating arm - I substituted Viton 'O' rings from here - http://simplybearings.co.uk/shop/o_rings.php The size range is so extensive you'll no trouble finding what you want.

Now the proof of the pudding. Gear changing is very positive & smooth when I spin the rear wheel or clutch drum but a road test will have to wait better weather. Fingers crossed.

I hope the above may be of help to anyone else who has to undertake such an overhaul.

Paul

Did you source one of these dished washers? I've just stripped my dolls head gearbox and the dished washer is pretty chewed up. Other than this it all looks to be in very good condition.

Thanks

Andy

Previously Andy Marks wrote:

Paul

Did you source one of these dished washers? I've just stripped my dolls head gearbox and the dished washer is pretty chewed up. Other than this it all looks to be in very good condition.

Thanks

Andy

I know it's 3 years ago Andy but did you find a source? Desperate for one!!

Dave

Hi David

No - I didn't, though I didn't spend very long looking. It's mainly there as an oil flinger to prevent too much oil getting out past the main bearing. With modern sealed bearings it isn't really necessary. I fitted a sealed bearing and then used regular shims to set the end float. I did the same thing to the laydown box on my ES2, this bike has covered over 8000 miles since I put it together 3 years ago with no trouble from the gearbox. The dolls head gearbox on the Inter (which I was asking about here) has done over 4000, again without any problems.

If I was doing another one Iâd be tempted to take the seal of the bearing on the inside. Get the gearbox oil lubricating the bearing but use the outer seal to stop (haha) the gearbox leaking. Best of both worlds!

Another reason for not fitting it is the number of people you talk to who have stripped a gearbox to find them in bits. If they have a habit of breaking up the last thing you want is all those bits rattling around between the gears!

Good luck

Andy

I think that we may be at cross-purposes here. The original thread was (I think) referring to the dished washer at the clutch worm end. I've never been aware that leakage past this bearing was a problem and a certain amount of oil is good for the worm.

The dished washer is quite a substantial thing and didn't appear in any of the pre-war or wartime parts books but was in the military M&I manual and the parts list for the post-war upright box.I can't see where the clearance to fit it could come from. Its spring function seems to be intended to keep the mainshaft pressed up against the bronze thrust washer.

Part No.29 in the exploded diagram.