The Merkur uses left and right handed nuts for the wheel bearings. The left handed ones have a yellow nylock insert in them. The right handed ones have a blue nylock insert. They are 41 mm or 1 5/8 in. They should be changed whenever you change the wheel bearings. They should be torqued to 229-251 Ft.Lbs. Make sure you check the spindles when you do this job because if it is slightly bent it will wear out the bearing quickly. The easiest way to do this job is to remove the hubs from the car. I have done it both ways and wouldn't even consider doing it on the car now.