JIm,

Over the years I have broken 3 of the inner drive axle "nuts" with the threaded body and square head.

One was removed using the tool that grips it and it spun off the inner stud. The other two would not loosen so I welded a nut on the end (disconnecting the computers) and used my impact wrench to remove them. I have no idea why one will break, but they do on occasion. I did change all of them on the first coach, but one of the new ones broke so I now only replace one if it breaks.

My guess is that if someone applied them without using the proper torque that may have contributed to their failure. I cannot remember if any I installed failed nor if the ones that failed had been installed by someone else. On a couple of occasions such as when getting new tires I allowed someone to install my wheels. Nobody but me has removed or replaced a wheel on my current bus, and I also have not had to replace a broken stud on this bus so that might have something to do with the failure.