Have you tried bumping it with an impact gun? That’s how I’ve got them off. You will need a pulled to get gear off. Do the marks line up on pump and plate? Do you see marks ?I'm trying to remove fuel injection pump from my 5105 that has 3029 engine. When I try to remove nut holding pump to gear, engine turns and of course nut will not loosen. What is the easy way to stop engine from turning so I can remove nut?