Have been away, so delayed response:
Rebound stops in place on both sides and in good condition.
With the suspension only partly dropped, the piston rod on what I thought was the dodgy cylinder does not have much free play in it and seems to be the same as the other side.
So, I don't think there is a problem with it.
Perhaps residual pressure in the Activa cylinder/sphere causes one wheel to drop more than the other when fully raised from the ground?
Perhaps the rattle is the Activa cylinder mounting bush after all.
Thanks to all for your help.
Simon.
REAR SUSPENSION CYLINDERS; XANTIA
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