A friend changed my front discs earlier. He had to remove 2 of these interesting looking things on 2 of the threads before the disc would come off. He said that they are not needed, but me being me I would like them as I am sure they are there for a reason!
Car is a 2003 Mondeo 2.5 V6. When you take the wheel off you have 5 studs, well there are 2 circular kind of flat things, copper looking colour. They seemed to be very difficult to remove so he cut some wire snips and cut them off.
Any ideas what they are called and are they necessary?