One day my stepfather was mowing with his 8N and he couldn"t get the clutch to release. They split the tractor and found a pin with a cotter pin missing in the pressure plate. They put it all back together with a new cotter pin and a new clutch disc. It has 3/4 inch of free travel and the clutch feels just fine but it drags bad. We cannot shift gears and to stop it in 3rd gear you have to use a lot of brake to hold it, we cannot drive it this way. Could he have put the disc in backward??? It feels fine but has a lot of drag? Any one have an idea? We may need a new pressure plate? Thanks