1955 16MS Clutch centre hub

[StevieL]

hello everyone
I'm very new t AJS motorcycles but I now own a 1955 350cc16MS

my concern is the clutch centre hub, I require a replacement part but at the moment I am unsure to order as the details say 5 plate clutch, is this referring to the number of friction plates? if so I require a 4 friction plate clutch hub.

any advice is greatly appreciated.

regards

Steve Lambert

[clive]

The 500 ran with 5 friction plates and the 350 with 4. The 5 plate clutch centre is slightly deeper and I do not know if the pressure plate will clear it if there are only 4 plates used. Someone here may know. The 5 plate clutch has a deeper clutch basket and maybe longer pushrod the parts list would confirm. So it is not just a question of extra plates friction and plain.

[SPRIDDLER]

Welcome, Steve.

I am unsure to order as the details say 5 plate clutch, is this referring to the number of friction plates?

If you look on page 23 in the AMC factory Spares List for your bike in the link below it will say what's what in regard to hubs an the number of plain and friction plates:

http://archives.jampot.dk/book/Spares_l ... ingles.pdf

I see that only the 5 plate hub is available from club spares and I don't know either whether the 5 plate hub will work with your 4 plate bits.
What's the problem with your hub?

[Reynard24]

Clive's suggestion to check the spares list for a definitive answer may be a little optimistic.
Looking at the 1955 AJS spares list the clutch basket/case or assembled clutch basket/case and sprocket are listed as G-36-3 and 018339 respectively and are described as for 5-plate clutch and are used on "ALL" but the accompanying illustrations also show part nos. G-36-5 and 018338 under the relevant parts but these are not mentioned in the spares list itself.
The 4-plate centre is listed as G-37-5, is it then reasonable to assume that G-36-5 would be the 4-plate clutch basket/case and 018338 is the 4-plate basket/sprocket assembly? All rather confusing!
As the club (and others) only list the 5-plate centre and clutch basket/case it might be worth measuring the depth of the original clutch basket/case and comparing that with 018339. If the depth is the same then you could conclude that the G-37-3 centre will fit along with the extra plates and a longer pushrod. It should also prevent any chance of clutch slip from the massive power of the 350 engine.
If the basket is not as deep as 018339 then Steve will need to order a new basket, centre, plates and the longer pushrod unless a four plate centre can be found on eBay, for example.
The only failure I've ever known with the clutch centre is striping of the internal splines that mate with the mainshaft sleeve (G-35-2) and I've seen this on two machines. In one instance these splines were repaired with wear hardening brass and gave good service for another twenty plus years before replacements became readily available.
If this is the reason for needing replacement it might be worth trying a local engineering shop to see if they can repair the splines.

[clive]

Well James it would appear that you need to look at more than one years parts list to get at the information. 53 they used two sizes of clutch basket 4 and 5 plate with different size centres. By 1954 they were using a single 5 plate basket but a smaller centre for the 4 plate. In 1955 they seem to have done the same.
Steve this amount of time since your bike was made you cannot be sure what year parts are fitted. The way forward is probably to check if there seems to be room in your clutch basket for a further friction plate and plain plate. If there is then you could fit a 5 plate centre but you would also need a longer pushrod and the extra friction and plain plate. If there is not room for more plates you will have to track down a 4 plate centre. Draganfly motors may be able to help.

[Reynard24]

Excellent sleuthing Clive. I have an original 1955 018339 somewhere, I’ll see if I can dig it out and measure the depth.

[clive]

Well I walk into the shed and realise I have all the necessary items on a table to answer this question. Unfortunately they are all for the CP box but I think all the dimensions will be the same.
The basket for the 5 plate clutch is 1 1/2 ins deep measured outside from the teeth to the edge. The 350 is only 1 5/16 deep. However. Putting 5 plain and 4 friction plates on a 5 plate centre appears to work provided the friction plates are not too worn out. Not actually tried it under load though.

[Trefor]

I have a G80S with 4 plate basket and a 5 plate centre boss. The giveaway is the clutch won't grip enough to kick the bike over. To make it work you need to make up a spacer disc to fit behind the pressure plate. I made it from 5mm aluminum and filed teeth into the hole in the spacer disc to key it on to the boss. Nothing you can't do in the average shed.

[StevieL]

hello All,

I rely appreciate you all for getting this brilliant information to me , that's brilliant, and a big thanks to you all.

I have replied to your responses, however, if I have missed anyone then I do apologies.

If anyone does come across a 4-plate hub please let me know if you wish to sell it to me, thank you once again.

Steve Lambert