I know it's not as elegant a solution as the ViseGrip-Phillips technique
![Smilie](http://www.986forum.com/forums/images/smilies/smile.gif)
, but I've found an impact tool very helpful for rotor positioning bolts. One whack with the hammer and-Presto!-the rusted whatever is loose, the head intact, and my screwdriver not gurred up by the mating session with the ViseGrips Just a thought