G12 Clutch identification and spares

Information relating to the Matchless G12 or AJS Model 31 650cc twin
Yves.Astein
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Joined: Sun Aug 26, 2018 9:07 pm
Location: Germany

G12 Clutch identification and spares

Post by Yves.Astein »

Hi to all,

I am quite new to the beautiful world of Classic Brits. So I could use some Help if possible. Thank you very much in advance.

I bought my self a 1959 Matchless G12. Unfortunately when I bought it the clutch was slipping.

So after reading the Workshop Manual and here in the Forum I opened it up and and made sure its adjusted right.

Unfortunately all seems good, but the clutch its still slipping. So I wanted to replace the friction plates and Springs or even upgrade the clutch if necessary.

And here come my questions:

Do I realy have a lightweight clutch with 3 friction plates (or sliping plates ;) ?

Please have a look:

Image


Image

Does it make sense to replace the Clutch-blades and Springs or should I upgrade it to the 5 friction blade version as mentioned in the Workshop Manual
The early type clutch can be converted by using the following components:
1 Back plate 040584.
1 Clutch sprocket 040359.
4 Steel plates, plain 043191. 4 Friction plates 043192.
1 Friction plate 043193.
If not, could you help me figure out the right Article numbers of the suitable friction plates, springs and Steel Plates for my current clutch set-up.
Since I am insecure about the clutch version I have , I am having trouble figuring the right part numbers in the Spares Catalogues which I have...

Would be grate, if you could help me to get on the Road for my first ride, before the winter sets in...


Thanks and Greetings from Germany Mainz

LeYves
MalcW
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Location: DEVON UK

Re: G12 Clutch identification and spares

Post by MalcW »

Hi LeYves

Have you tried tightening down the clutch springs? You really want the top of the screw to be about level with the top of the stud. From what I can see in the first photo yours are looser than that. Then make sure the clutch is opening evenly all round when you pull in the clutch lever.

Malc
Yves.Astein
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Posts: 90
Joined: Sun Aug 26, 2018 9:07 pm
Location: Germany

Re: G12 Clutch identification and spares

Post by Yves.Astein »

Hey Malc,

No I havent screwed them in as far as the verry top being flush with the Studs. (With studs you mean the stud, that the spring tightening bolts are screwed on ? )

So far I thought the outer rim of the spring tightening bolts need to be flush with the clutch basket...

Like this:
Image

Ok, so ill try tightening them more.

Thanks for the hint !!!




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MalcW
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Location: DEVON UK

Re: G12 Clutch identification and spares

Post by MalcW »

Hi again

Yes, that's what I mean. Once you've done that, pull in the clutch lever and use the kickstarter to turn the clutch, and check that it opens evenly all round. Adjust the springs if necessary. Also, are you sure the clutch pushrod is adjusted correctly, and isn't too tight? You should loosen the clutch cable completely, then screw in the adjuster in the middle of the clutch until it just touches the pushrod, then turn it back half a turn and relock it. Check it hasn't moved, and then re-adjust the cable to give a few mm slack at the lever. You've probably seen this, but instructions on this and everything else are in http://archives.jampot.dk/book/Workshop ... CHABLE.pdf

Good Luck

Malc
Yves.Astein
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Posts: 90
Joined: Sun Aug 26, 2018 9:07 pm
Location: Germany

Re: G12 Clutch identification and spares

Post by Yves.Astein »

Hi Malc,

Thanks for explaining things again although it has been explained before. Guess I was insecure by some posts where people where arguing about what needs to be flush.

Well i got to tell you after flushing with the studs, the slipping is gone. And she rides like a dream. Uhh I just had an hour of flying with my lady.

Thank you verry much !!!

P.S. Although pulling the clutch is some hard work now. Is that normal ?




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dave16mct
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Location: LANCASHIRE UK

Re: G12 Clutch identification and spares

Post by dave16mct »

Make sure you route the cable properly, nice smooth route to the gearbox. Oil the cable or fit a teflon-lined one. Most important though is to check you have the correct handlebar lever. The distance from the centre of the cable nipple to the centre of the pivot should be 7/8" (about 22mm). Most pattern levers are much larger, and the clutch will be very heavy.
Dave.
Yves.Astein
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Location: Germany

Re: G12 Clutch identification and spares

Post by Yves.Astein »

Pivot to niple is exactly 22mm. Maximum bent radius is of the cable is 150mm...


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Yves.Astein
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Location: Germany

Re: G12 Clutch identification and spares

Post by Yves.Astein »

I oiled the cable that made it a bit better. I might turn the clutch springs out a bit again to find the slipping point...


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Yves.Astein
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Joined: Sun Aug 26, 2018 9:07 pm
Location: Germany

Re: G12 Clutch identification and spares

Post by Yves.Astein »

For everyone else who might want some orientaion on this. Here is my setting that cured the slipping. Il might loosen a bit again sins pulling the clutch is still quite hard...

Image

Made my self a litle tool as well:

Image

Ill let you know what I end up with at the end...
SPRIDDLER
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Re: G12 Clutch identification and spares

Post by SPRIDDLER »

LeYves23 wrote: Il might loosen a bit again sins pulling the clutch is still quite hard...
To avoid keep getting kitted up and testing on the road I set my clutch springs by putting the front wheel against a wall, engaging first gear and trying to stall the engine. It isn't necessary to rev the engine's heart out or try to push the wall over but rev just enough as if pulling away from stopped, or under load and riding uphill. You'll soon get the hang of how much spring pressure is needed to give the lightest action but adequate grip.
'There is a tide in the affairs of men
Which taken at the flood............'
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