G3LS swing arm details

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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G3LS swing arm details

Postby murraymck » Wed Jan 13, 2021 9:44 am

Three months ago I purchased a 1951 Matchless 350cc G3LS and joined the club in the last few days.

The frame and wheels are still assembled and the rest is in boxes, but a close look through the boxes seems to look like it is very complete.
I decided probably the best approach would be to start work on the frame and wheels to get a good base on which to sort out how the rest all fits together.

My first question relates to the swing arm bush lubrication. On my bike the steel pin that the swing arm pivots on has 1/4" Whit countersunk screws holding the outer covers in place on each end and the left hand end has another screw offset which I have read is for adding a heavy grade oil through. However, there is no connection to the RHS as both threaded holes are blind and have always been that way as on close inspection evidence of the tapping drill finishing the hole bottom is there.

What has happened of course is that the RHS bush has tightened up forcing the pin to turn in the aluminium/diecast casting which is now slightly worn and obviously something I need to address.
I read something about a spoke holding the end caps in place but because mine isn't like that and clearly needs fixed so oil can get through can anyone help please? I am keen to get it back the way it should be.

Was there also anything that prevented the pin from turning in the casting originally, apart from a fit tighter than the bushes?

Finally I am missing the sidestand and thought I would make one and wondered if anyone would know how long they are and an approximate diameter or possibly direct me to a drawing or photo of one that I could copy please?

Thanks
Murray

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Re: G3LS swing arm details

Postby dave16mct » Wed Jan 13, 2021 10:49 am

The original 'pin' is actually a hardened steel tube which is the reservoir for the sae140 oil. It's a pressed fit in the alloy casting. I think you should get the correct pin and fix it in the casting with cotter pins like the later models had. Then you only need the spoke to hold the end caps on and 2 paper gaskets to seal them.
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Re: G3LS swing arm details

Postby SPRIDDLER » Wed Jan 13, 2021 12:57 pm

You might find this article useful - refers to s/arm bush lubrication and semi-captive cotter pin.:

http://www.jampot.com/article_read.asp?id=227
I poke badgers with spoons.....from 2 metres.

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Re: G3LS swing arm details

Postby murraymck » Fri Jan 15, 2021 10:40 pm

Thank you very much for your help. This has definitely put me on the right track now.

Murray

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Re: G3LS swing arm details

Postby dave16mct » Fri Jan 15, 2021 11:34 pm

This video will help: https://youtu.be/yFiDL-Evle8
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Re: G3LS swing arm details

Postby 56G80S » Tue Jan 19, 2021 4:38 pm

Dave

That is a brilliant link. I watched it all, despite the fact that I've done the the job in the past successfully. I'll be searching for more from him just for interest. I could do with a micrometer like that with a radout to check some parts (timing side axle and bush)

Mum (previously a machine setter) left me several in differing sizes but I have no idea how to read them. I know it should be commonsense - I have none. The cheap Lidl vernier gauge just isn't good enough as it has trouble returning to zero after use and therefore I have no confidence in the readings. Perhaps I'm doing that wrong too (Mum also left me a vernier but it doesn't go to small tolerances)

I'll see if I can find some instructions on the net.

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Re: G3LS swing arm details

Postby dave16mct » Tue Jan 19, 2021 4:57 pm

My mum didn't leave me any micrometers but she did leave a book on how to use them! She was an engineer during the war, working at Aintree Rifle factory then Brockhouse Engineering at Crossens near Southport.
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Re: G3LS swing arm details

Postby Mick D » Tue Jan 19, 2021 4:59 pm

Hi Johnny

Learning to read a micrometer and vernier will take about 10 minutes - 10 minutes well spent and you'll be able to do your Mum's tools justice ;)

http://www.chicagobrand.com/help/microm ... e%20sleeve.

https://www.miniphysics.com/how-to-read ... liper.html

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Re: G3LS swing arm details

Postby 56G80S » Thu Jan 21, 2021 12:05 pm

Apologies murraymck!

Mick D - Thanks. That makes everything a lot clearer. The zero adjustment suggestion will be a help too!

I'll print as memory fails and will now use Mum's kit. As Dave16mct mentioned, my Mum was also carrying out war work. Apparently related to setting up the machinery for radar.

Best wishes

JohnnyB

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