All done, the quadrant stop was just loose, the hole was ok so I fitted a new stop without removing the back plate.
The tooth grinding feeling when I kicked it over was found to be the drain plug. To make things easier when changing the gearbox oil I had changed to a ½" long whitworth bolt, when I removed it I noticed that it had some wear marks on the end, I ground some off and all is ok now.
Thanks to everyone for the help.
Roy.
