Trying to replace the grease in part of our system with a dry film lubricant.  The application is for a ball bearing (chrome steel) running in a helical (Rc 60 D2 steel) track.  The high pressure on the ball (~100ksi) and the twisting, scuffing motion at the contact patch causes the system to fail from an adhesive wear condition after only 3K cycles if run dry.
  The current grease is a high-moly grease with 30% molybdenum content.  It works well for over 1 million cycles, but is dirty and tends to contaminate other parts of the system.  We would like ot replace it with a dry film lubricant of some type.
  We've tried a number of options already TiN, WS2, MS2, but so far, the best we have tested has been Xylan (it got ~90K cycles before failure).  Unfortunately we need life in excess of 250K cycles.
  Any suggestions on coatings that might help get us to our bogey?  All help is appreciated.

                                   - Rich