Silentbloc bushes

Currently rebuilding my 1969 BSA B44 VS and the time has come to strip
it back to the frame for powder coating. I have a quick question about
silentbloc bushes in the swinging arm.

I've not come across these before and am not sure how they're meant to
work.

If the swinging arm shaft is not tightened at both ends the swinging
arm has unacceptable play. If I fasten the plate at the left hand end
and tighten the nut at the right hand end of the shaft the whole
swinging arm seems to be held tightly and be damped in its up/down
movement.

Is this how it is meant to be? IE, does tightening the sw. arm shaft
compress the rubber in the bushes to its working tension?

How can I tell if the silentbloc bushes need replacing?

cheers

Antony

 

Sideways play.

 

The Older Gentleman says...

Is that a euphemism?

 

With that sort of bush the metal bits should be tight on whatever holds them
IYSWIM and movement is provided by distortion of the rubber, so it is
important to tighten the shaft nuts when the arm is in its normal static
laden position.

If the rubber is in good nick and still bonded to the metal bush(es) all
should be well.

Ron Robinson