The nut looks like disc stacks that get sandwiched down when torqued. I replaced mine when I installed new hub assemblies. You can only get the nut from Ford. The only other parts you need is the dust cap and assembly (either ABS or non ABS). Rent (free rental from auto store) a 250# torque wrench (300 n-m is what they really are) unless you happen to have one. The nut needs to be put on at 254#, if I remember correctly, but it has been 1.5 years.