well took the bevel gears and pinion round to the engineering shop and he had a good look at them and reckons they don't need anything done to them he would class it as normal or minimal wear and to give the box a good clean to remove the old grease and then put it back to gether and fill with liquid type grease and it should be fine .
he did say it may have been the old grease that caused the problem other than that he could see no obvious problems with the gears or pinion .
so I will get new nuts & bolts then put it back together .
