The washer is just an 1/8 thick (just installed one yesterday) just get a proper washer to fit the shaft snuggly (inside diam.) and it will work fine. P.S. just a tip .....when you come to installing the horn button sand off or sratch some of the paint(on the wheel if you have a painted one) for the opposite side of the fiberboard (metal side) that comes in the install kit, so the horn will work. LOL..... I had scratched my rearend for 15min. as to why it wasn't working! lol lol My only excuse , It was Monday.