I changed the anti roll bar bushes (decent ones) and peace was restored.
The other day the donkey returned but is now living on the O/S. I did a run to Nottingham from Glasgow last weekend and I now also have a nice creak as I travel along.
Reminds me of the truck at the Kilamanjaro Safari in Animal Kingdom

I will get a look at the ARBs again but if anyone has any suggestions as to why they should to be so noisy again or anything else it may be I would be grateful.
Derek