XSarge wrote:Thank you very much for the help. Should I buy 4 caps or will the 3 be exact matches to the one I have?
You're very welcome

!
Personally, I would just go ahead and buy 4 of them. Looks-wise (the side you see), they're exactly the same, but the backside (the side that attaches to the
center of the wheel) is what they changed per the TSB. If you don't replace the 1 you have left (the old, problematic version), it will more then likely end up falling out eventually, so do the next owner a favor and just go ahead and order 4 of them now and replace the 1 that's left so all 4 are indeed an exact match and shouldn't ever fall out again.