Yes those do break off after a few miles have been put on them. Make sure to use the same Factory Studs, this way if broken it's easier to drill out or remove than say a Black iron stud or the like. Did you back it out while cold? I usually heat up the studs with some light heat before removal to help with removal so as to replace them slightly expanded, with the wiring completely out of the way. That sometimes works and sometimes doesn't. If you can Replace all of them with no sealant and you should be ok for a while. Good luck.*Jimi