Twin down tube frame, cotter pins??

[Ianwilko13]

While removing 0.015" of side play on my swinging arm, I noticed 2 holes on the central bridge with nothing on them?? I think that cotter pins should be fitted but the holes are empty, there is no undue movement in the assembly? Many thanks for any suggestions, Ian.

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[Duncan]

I cant see the holes in your pictures, however if they are the cotter pin holes you would have to remove the swinging arm pin to fit them as they are sculpted not tapered.
I noticed an additional fitting on the centre stand retaining spring, what is its function?

[Ianwilko13]

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Thank you for your reply Duncan, the extra part you noticed is a cap head screw with a price of fuel hose over it fitted by my self to stop the center stand from hitting the exhaust as it was knocking the chrome off. The mysterious hose is a return pipe to the oil tank from the engine breather (some body else's idea) I have pushed a cable tie through the 2 holes and I'm sure cotters need to be fitted, I will be going over Kettering this morning for spares, are any special tools needed to strip the primary drive case off?? Kinds regards, Ian.

[Duncan]

Just to confirm we are talking about the same holes I have pasted and extract from a parts book below:

cotter pin location.png

I'm not sure what year and model your bike is but generically speaking other than new gaskets and time to do it you shouldn't need any special tools, there is a clutch removing tool for AMC clutches but I've never needed to use one. The pin can be a swine to move if its been in a long time so you may wish to get a new one, if its been replaced recently hence the missing cotter pins it shouldn't be a problem and should be okay to reuse.

[Ianwilko13]

Hi Duncan, yes they will be the same holes, the model is a Matchless G3 (1961) I have picked up the parts needed as I already have primary case gaskets to hand, I am sure that by removing the wheel, shock absorbers and chain guard I could insert the cotter pins by shaving then down with a Dremill, but as I have time on my hands I will strip the primary case off and pull the pin to do the job properly, I'm sure that shaving the pins down to insert from one side wouldn't weaken the job though as no cotters have been fitted for 3,500 miles, I will post updates of any problems, many thanks again, Ian.

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[Duncan]

I'm sure that shaving the pins down to insert from one side wouldn't weaken the job though as no cotters have been fitted for 3,500 miles, I will post updates of any problems, many thanks again, Ian.

That sounds like a neat solution.

[Ianwilko13]

Hi Duncan all parts separated and in spec' will clean & assemble tomorrow, many thanks again, Ian.

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[Ianwilko13]

Hi all, does this look correct as cotter pin could be inserted either way many thanks in anticipation, Ian.

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[Duncan]

That looks correct, from memory you should be able to see a slight machined flat on the bridge that the washer sits on.

[Ianwilko13]

Thanks Duncan, there is a flat face for the washer to pull up to and access for tightening will still be OK once the swinging arm is in position, many thanks, Ian.

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