I went to the automotive shop the other week to pick up a pair of "Double lip" seals in order to repack my bearings. The guy at the counter said they have many sizes and asked me which one I need. How can I find out without taking the bearings apart? I have a 1997 single axle zeman trailer.<br /><br />Also, I believe there is a cotter pin I will need to replace too when repacking the bearings-- what size cotter pins should I pick up? Anything else that might be size/type specific? Thanks very much!