"Jingling" sound in Mk3 rear hub

One for the Mk3 owner's memory banks...
Have just finished helping a friend change out both final drive sprockets and chain (to x-ring, 530) on his '75 850.
After finally buttoning everything up (waiting for parts in Australia!) he was happy and things looked rosy.
Next day he reported "funny noises" coming from the rear end,
Closer inspection indicated a very metallic jingling coming from the rear hub "cone" - but how could that be?
The answer was the backplate (https://andover-norton.co.uk/en/shop-details/16386/backplate) was jingling loosely behind the cush,
A bit of hairspray (his wife was amused!) and some blows from a rubber mallet fixed the problem - all good now.
We reason that the problem was probably initiated by "roughish" handling of his rear wheel by a local tyre fitter. We were too worried to pull the cush out because the rubbers were old and probably too hard to go back in properly.
He probably really needs new cush rubbers - but - that'll happen sometime soon!

Posted as a "heads-up" to other Mk3 owners who may not have seen this
Cheers
Rob

BTW - special tool #5462 was invented (re-invented?) during this job.
Needed something to keep the brake pads in place during the refitment of the rear caliper (Norton really like to make things easy, don't they!} and keeping the pads in was a problem.
A solution, we found anyway, was to slip the end of a length of 5/16 clear fuel hose between the pads.
When the caliper was easily lowered over the disk, the hose was simply pulled out - Bob's yer uncle and Bernard's yer aunt!
Cheers

robs ss said:

Closer inspection indicated a very metallic jingling coming from the rear hub "cone" - but how could that be?
The answer was the backplate (https://andover-norton.co.uk/en/shop-details/16386/backplate) was jingling loosely behind the cush,

Click to expand...

Yes, it's a fairly common Mk3 problem and has been mentioned a few times.

robs ss said:

Needed something to keep the brake pads in place during the refitment of the rear caliper (Norton really like to make things easy, don't they!} and keeping the pads in was a problem. A solution, we found anyway, was to slip the end of a length of 5/16 clear fuel hose between the pads.

Click to expand...

An alternative would be to follow the instructions and use the tool (wheel/chain adjuster) as described in the Mk3 factory manual (Sections H1, 7 and H2, 4 & 5).

Sorry for the delay in replying. I just stumbled over this thread. A possible cause of the noise is a defective, original style lock ring [item 18 linked below]. The original items were pressed together from two pieces and often separate. This allows the internal bits of the cush drive to move apart. Once this happens, the back plate [item 17 linked below] can rattle. The lock ring has been redesigned. Andover Norton now sells a "machined from billet" one piece lock ring which can not separate.

Mk III Rear Wheel Exploded view

Ask me how I know!