While we're on that subject, did you check your drive angle as well? Make sure your springs aren't sagged and pulling down on the drive shaft. That will toast a u-joint faster than you can put it in. Ask me how I know...
My car came to me with airshocks and I thought that was great until I read up on them. Further inspection I noticed that my entire rear axle had rotated about 15 deg forward (down) when I dropped the pressure on the airshocks. I kept hearing what sounded like an airplane propeller when I was driving. The u joint was smoked and the clips were all bent out of shape
Replaced both springs, added a 2 degree shim, and new Spicer u-joint in the rear. New KYB shocks as well. All good now