Thanks djm for the info.Yes . I just got the bushes out they had been squeezed in with corrosion. It had two bushes in-line on each shaft with a gap between them of about 4mm between. I did not have any O ring in there at all that I could see.Maybe it was between the bushes and now gone ? If the O ring is not between two bushes what would hold it in place ?Do you know where I can buy replacement parts ?Regards Andrew