As you have shopped for ball joints, you may have noticed that some brands come with rubber boots and some don't, which makes you think, "What's that about?" On a typical street car application, where maintenance is not done on a weekly basis, the boot is perfectly acceptable, as it will help to keep out the rain water and the small amounts of dirt that may come in contact with the ball joint. But in a racing application where everything needs to move as free as possible that boot may do more harm than good, as it can trap contaminants and increase resistance. As extra grease builds up in the boot, it increases the resistance on the stud. That grease has to be moved out of the way as the stud moves, so that low-friction ball joint that you bought is not as free moving as it could be. Running the joint without a boot allows for contaminants that may have gotten down in the cup to simply be pushed out and replaced with clean grease, and the excess to be removed entirely. It's recommended that greasing of the ball joints be a part of your weekly maintenance program. –Pete Epple
