How to align engine- and clutch sprocket?

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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How to align engine- and clutch sprocket?

Postby schrottschlecker » Mon Apr 16, 2018 8:49 pm

Hello,

I have an issue on my model 18S primary chain alignment. In my basketcase-box, I found the bits for the front assembly:
inner collar ring: 7,8mm wide, 25mm OD, 31,4mm ID
engine sprocket 25mm wide
outer collar ring 10,3mm wide, 19,7ID, 31,6 OD
plus rotor, washer and 2 nuts

When I push the clutch basket on the main shaft, the inner hub scratches on the inner primary chain case and the chain is very tight to the case. There is a misalignment of more than 3 millimeters.
I have no clue what to do? Is there a distance ring missing between clutch and main shaft ring? I cannot find anything like on the spares list nor on the exploded views.

It would be great if anyone has an idea.

Cheers,

Christian
misalignment.jpg

c1.jpg

c2.jpg
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Re: How to align engine- and clutch sprocket?

Postby Rob Harknett » Mon Apr 16, 2018 10:35 pm

I don't know, but, could you have a distance ring behind the engine sprocket that could be wrong? You do not state what year your 18S is, which may need to be known.

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Re: How to align engine- and clutch sprocket?

Postby schrottschlecker » Tue Apr 17, 2018 5:29 am

The engine is from 1958, the frame is a later dual frame. AMC gear box.
The engine sprocket position looks about right. In my opinion, the clutch is too close to the inner primary case. The bike was running before the previous owner disassembled it partly.

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Re: How to align engine- and clutch sprocket?

Postby SPRIDDLER » Tue Apr 17, 2018 9:33 am

schrottschlecker wrote:Is there a distance ring missing between clutch and main shaft ring? I cannot find anything like on the spares list nor on the exploded views. .........the inner hub scratches on the inner primary chain case and the chain is very tight to the case.

It would seem that the clutch basket is too close to the primary case.
Have you fitted the spacer 040131?

Gbox spacer 040131.JPG


Spacer gbox sprocket.JPG
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Re: How to align engine- and clutch sprocket?

Postby ajscomboman » Wed Apr 18, 2018 6:04 am

It's also possible that the clutch centre spider is worn due to the locking nut working loose and the spider fretting. This causes the spider to engage further onto the spline as the ends stops of the spider have worn. Had it happen to me once before, a new spider cured the issue and stopped the basket fouling the chain case when the chain went on.

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Re: How to align engine- and clutch sprocket?

Postby mikeydpippin » Wed Apr 18, 2018 9:12 am

On my 1963 there is a spacer behind the clutch basket,(same as Neville shows in diagram) and I had dragging from the clutch basket onto the rear chaincase, there is a raised ring imprinted on the rear chaincase, and the clutch basket was slightly touching it, filed the high spots on the rear chaincase and now all quiet.
That was ok before being stripped.
Not sure if any help, but it worked for me.
Mike

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Re: How to align engine- and clutch sprocket?

Postby schrottschlecker » Wed Apr 18, 2018 8:35 pm

Hello,

there is a spacer which sits in the floating washer insert of the inner chaincase. The spider just stops before it touches the ring when fully pushed on.
shaft.jpg

I have pushed the rear end of the case further inboard. It fits flush with the outer case and looks straight.
Now the spider does not scratch the case any more.
spider.jpg

The engine sprocket ring is 1,1mm wider than original according to the information that I found in the forum.
I will make the front ring 1,1mm norrower and guess that should be ok. The test was ok. I also realized that the clutch sprocket floats in the sprocket inserts, which are about 3mm thick. So that will find its way for a good alignment.
alignment.jpg


Now I need to see how to tighten the clutch hub. I have no tool for the 5/8" nut that fits insite the hub :shock:

Thanks so far for your help.

Christian
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Re: How to align engine- and clutch sprocket?

Postby Duncan » Wed Apr 18, 2018 9:06 pm

The engine sprocket bears on spacer 040131, if fits inside the mainshaft oil seal, this will not affect the depth of the clutch basket.

I have no tool for the 5/8" nut that fits insite the hub


This nut should have a reduced hexagon, often previous owners put a full size one in leading to difficulties, if the nut is correct a plug spanner will fit it, 3/8" drive sockets often fit, I have had to grind a cheap socket down to suit a full size nut before.

The "spacer" in your Shaft.jpg picture is the end of the sleeve gear and not a spacer if you look closely you can just see the bush in it, this should not contact the clutch basket.

Does the mainshaft have any movement/float in and out on it or is it held firmly?

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Re: How to align engine- and clutch sprocket?

Postby peyton » Wed Apr 18, 2018 9:26 pm

Hi Christian, I've just done my Norton clutch, & used a long spark plug socket to tighten the clutch centre nut. Regards Neil.

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Re: How to align engine- and clutch sprocket?

Postby schrottschlecker » Thu Apr 19, 2018 6:55 am

Duncan wrote:The engine sprocket bears on spacer 040131, if fits inside the mainshaft oil seal, this will not affect the depth of the clutch basket.


According to my information, the spacer is 023066 with a width of 6,7mm. I guess you are referring to the Twins.



The "spacer" in your Shaft.jpg picture is the end of the sleeve gear and not a spacer if you look closely you can just see the bush in it, this should not contact the clutch basket.

When I push the clutch hub all the way on the shaft, it does not touch the sleeve. So a spacer would not be correct.

[/quote]Does the mainshaft have any movement/float in and out on it or is it held firmly?[/quote]

There is no noticeable float on the gearbox main shaft.

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