[folivier]

Had something similar happen when I changed the tires in San Antonio. These are called bud nuts, they screw onto the studs to hold the inner tire and have threads to hold the outer tire on. Dealer got lucky and only 1 broke but took them 2 hours to remove it. But then they broke 3 regular studs on one wheel so I had them replace all of the studs. It took over an hour running around San Antonio to find them but finally found the studs at a big trailer supply place.