thanks everyone for offers of help and advice, just goes to show that we really have the greatest set of fans in the world ;-)
I have now got this sorted, yes Ponty, you were spot on, it was the bearing but also the plate was knackered too. Managed to get it £150 cheaper by buying the part myself and taking it to them, they werent too happy but after i said that id take it elsewhere they soon changed their mind.