Just to let you all know after the enjoyable destruction of the nut with a nut splitter very therapeutic!!!! then knocking the bolt out with a 2.5lb lump hammer and refitting all new bits with loads of copper grease. It is all done just got to fit the sliders now spent the rest of the afternoon with a huge rat tail file clearing the jacking point out so all should be well!!!! Thanks for the advice and the kick up the arse to do it...