Clutch adjusting issue

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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G3L1946
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Re: Clutch adjusting issue

Post by G3L1946 »

Hi,

I think this confirms new thrust rod!

Regards,

Steve
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G3L1946
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Re: Clutch adjusting issue

Post by G3L1946 »

Hi again,

Taking up the point from Duncan re thrust dowel. Not a very expensive part but is it a big job to replace it? Are they prone to much wear? I’m not absolutely clear as to its function. Learning all the while! I will replace the thrust rod in any case.

Regards

Steve
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Rob Harknett
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Re: Clutch adjusting issue

Post by Rob Harknett »

The thrust rod & clutch seems to be working OK, In fact every thing is OK ????? So why won't the nut go on????
You must have the wrong length thrust rod. 55 thrust rods are 9 7/8" ( 4 plate clutch ) 10 3/16 ( 5 plate clutch )
all balls 5/16" dia. Get that all correct and the lock nut should go on OK. Assuming you have a 55 350 G3LS with correct gearbox and 4 plate clutch.
your thrust rod should be 9 7/16" long. Thrust rod ends are case hardened. Your parts list confirms all the above, its not always easy for a new comer to find their way.
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G3L1946
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Re: Clutch adjusting issue

Post by G3L1946 »

Hi Rob,

This is the cause for my bewilderment! It’s definitely a 55 G3LS. I have measured the rod length and it is, as you say, 9 7/8 “ long. However ,BOTH ends are cupped. This would indicate that the rod has, at sometime, either been turned around or , as I believe in my case, had a ball each end ( incorrectly). It’s a four plate clutch and all else is correct. I’m thinking that cupping may be causing the problem? We’re talking about 1/10 ins to bring the thread though to be flush with the nut. The clutch basket is fine and must be correct as it will only accommodate the right amount of plates. Correct gearbox for year.
Still scratching head!

Regards,

Steve
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Re: Clutch adjusting issue

Post by SPRIDDLER »

G3L1946 wrote: Sat Sep 04, 2021 8:54 am Taking up the point from Duncan re thrust dowel. Not a very expensive part but is it a big job to replace it? ..I’m not absolutely clear as to its function.
The dowel (35-3-4), along with its spring, washer and split pin hold the two clutch actuating plates (G-33-2 and G-33-3) together, with the balls (17-3-2) sandwiched between them.
I've never needed to replace the dowel.
Burman B52 dowel.JPG

Exploded view of the whole 'box here:

http://archives.jampot.dk/technical/Tra ... d_view.pdf
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G3L1946
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Re: Clutch adjusting issue

Post by G3L1946 »

Hi Spriddler,

Thanks for information. Trying to avoid unnecessary jobs so good to hear you’ve never needed to replace one. I’ll get a new rod and do a bit more fiddle work. The clutch works nicely it’s just I’m not happy with not sufficient thread being employed.

Cheers,

Steve
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Rob Harknett
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Re: Clutch adjusting issue

Post by Rob Harknett »

I did make a typo in my last posting Thrust rod 9 7/8" I then stated at the end, in correctly 9 7/16"
The trust rod should have only one ball the gear box end. Sounds like your thrust rod was not properly case hardened.
I recall when I was 17 back in 1957, I went to my local dealer for a new thrust rod for my 55 G3/LS.
He supplied one made to measure. He came back to the counter with a piece of rod and checked it was the right size against my old one. I picked it up, he grabbed it back saying, I need to case harden the ends first ???? He explained what that meant, showing me my cupped rod.
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G3L1946
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Re: Clutch adjusting issue

Post by G3L1946 »

Hi, interesting. I’ve just removed the rod and given it a good clean and further inspection. It is significantly cupped at both ends. Approximately 0.32 mm in depth each depression ( doesn’t sound a lot, but quite obvious ).
I’ll take a look at it from the bottom up and see if I can identify any issues. As stated, I will replace the rod ( measurement of mine is 9 7/8 long ).

Regards,

Steve
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Rob Harknett
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Re: Clutch adjusting issue

Post by Rob Harknett »

For consideration 5 steel plates 4 friction Thickness of corks ???
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G3L1946
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Re: Clutch adjusting issue

Post by G3L1946 »

Rob,
Correct. 5 Steel, 4 friction. Not sure re thickness of corks but purchased from club so presumably acceptable.
Just clutching at straws now by measuring clutch cable length to check correct length . It’s about 43 7/8 ins wire length ( to get anywhere near where I want it the adjuster at gearbox is nearly fully wound out ). Just about to check parts list for 55.

Steve
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