equal-i-zer

I have greased both the ball and inside the sockets where the spring bars are inserted, and there was no appreciable difference.

I don't think lubricating the inside of the socket where the bars go will have any effect. But with how noisy these things can be I can fully appreciate trying anything and everything to make it quieter. I know on mine the noise was coming from the friction between the outside of the sockets and the head.