[phutton]

Many thanks - I'm glad to say we do have it in the Archive!

P.

[wessex_man]

Yes it's a two page article from 'The Motorcycle'  May 28th 1936 pages 712 and 713 Titled 'The 346cc Overhead valve Sunbeam' .  I think I found it when researching my 1st beam a 1935 M8. I sold RFF when my 1929 M9 was restored and running quite a few years back.

The National Motor Museum Library has an extensive run of literature. I think we found it there. When interested in a bike popped over to get some info on it. Now you have to book an appointment though. Well worth visiting when down in the Forest.

http://www.nationalmotormuseum.org.uk/About_the_Motoring_Reference_Library.

[phutton]

So that I can check if we have it on the Magazine Article List, could you let me know the date of the issue it came from?

Ta!

P.

[VicYouel]

Dave, thanks for the article...... never seen that one.

Vic

[tomleavy]

Vic-
Thank you for your reply. That article was most helpful. I learned that the bearing was not pushed in far enough. The outermost part of the hub is damaged where the threads are for the threaded disc. I am trying to figure out a workaround for that.

Tom

[wessex_man]

Hi Tom,
you have got one of the last four speed boxes with clutch arrangement used in 1935/6 just before the Burman box was introduced. The bearing was meant to stabilize the clutch center which it does if you have all the bits. You are missing the end cover which locks the bearing in place and clutch centre is pretty beat up the threads are missing. (We had a 1935 9A which used this arrangement). The gear box main shaft differs from other 4 speed boxes so it can accommodate this clutch arrangement.

I think this page from motorcycling shows you how it all should go together and works.


PS you might want to consider a replacement bearing KLNJ1/2 (R8 EE4) imperial deep groove Ball Bearing 1/2x1-1/8x1/4 from simpley bearings @ £4.46 ex vat. (price mag have gone up now)

[tomleavy]

Thanks for the reply, Vic.

Since my initial post, I read about AU gearboxes in an article by Derek Bennett in the winter 12/13 Beaming. Apparently what I have is correct for my bike. There is a threaded hole for a grub screw to catch the clutch securing nut. There are two additional holes, which I initially thought were for a cotter pin, but I forgot to take into account the main shaft, so the cotter pin would not pass through. I guess the grub screw is the only part that captivates the securing nut.

Tom

[VicYouel]

Coo...er what carnage. My clutch shaft nut is secured with a simple tab washer. The bearing might as well be a bronze bush as it only performs its function when the clutch is disengaged. This means it must also be able to slide along the shaft. Kind of an overkill.

Vic

[tomleavy]

I am slowly digesting this clutch arrangement, but am still unsure about the pouter bearing, as shown in the photo.

It seems the nut, also in the photo, is retained by a grub screw after tightening, and then a cotter pin is passed throughout the sleeved outer end of the clutch hub which prevents the nut from backing out. If anyone can confirm this, it would be most helpful.

Regarding the bearing, I don't see what purpose it would serve, as it would be going along for the ride with both the clutch hub and the main shaft of the gearbox

[tomleavy]

I am having difficulty with the kickstart quadrant slipping when engaging the gear behind the clutch hub. I followed Vic's advice and opened up the clutch again because the clutch drum was too loose. After removing the plates, I took a better look at the outer bearing, and noticed it was loose. It slipped right out, and then I determined that the nut that captivates the clutch hub was indeed loose.

The nut and the clutch hub both show some damage. The clutch hub must have been worked over by a brute with a chisel and hammer. There is a small chunk missing from the end of the sleeve of the hub, and the part of the sleeve that receives the bearing is a bit out of shape. Also, the two slots on the nut are a bit disfigured, but I think the part is serviceable. I have attached a photo of the sleeve end of the hub. It looks worse in the photo than it actually is.

My question is, how tight must the nut that holds the clutch hub be?

Also, there are four holes in the sleeve of the hub- are these for grub screws, of for priding our the bearing or?

Tom