I am triing to design a clutch for an extremely high vibration application.  The clutch consists of multiple compressed beveled disks.  I am currently using about a ten tooth spline in the clutch with three keys on the outside to drive the clutch housing.  I am using pretty tight tolerances already, but was wondering if there is some type of lubricant or dampener material, different shape, or anything else that you can imagine to minimize the axial play.  Keep in mind that this is very high vibration up to 78.4 Grms.  

Thanks a lot