To absorb the vibration we usually use some plastic material that we can buy from hobby shops and usually is in the package with the servo you're buying. It does very good job, but on the other hand, why are you having vibration problems that they are capable of killing servos? The only killed servo i had, it was in my plane when that crashed (fortunately, i assembly it again as well as was, but the aileron servo killed, so i change it). Is your engine suffer from horrible vibrations??? []