Sometimes you can see the pen marks made by the factory on things like brake rotors and the accompanying set screw. Once the set screw is undone, the pen marks no longer line exactly up, or the replaced part no longer has pen marks on it while the set screw does.
Sometimes you can see the pen marks made by the factory on things like brake rotors and the accompanying set screw. Once the set screw is undone, the pen marks no longer line exactly up, or the replaced part no longer has pen marks on it while the set screw does.