Over time, gravity settles the grease below the control arm, ball joint leading to a metal-on-metal squeak. I just fixed my front end, ball joint squeak without injecting grease or replacing the control arm. Jack up the car; remove the tire, and; remove the clamp bolt. Then use something like vice grips to grab the ball joint shaft and squeeze the boot to get grease in contact. Move it back and forth to coat the ball and the resistance and squeak goes away. The only problem was the clamp bolt threads were wiped out getting the bolt out: So I walked over to Mike's Merchandise, a neighborhood surplus parts store, and bought a substitute bolt, two washers, and locking nut, $0.28: Those are WD-40 spray stains on the wheel well. I also squirted down the control arm bolts. Bob Wilson ps. I was inspired by a UK YouTube that correctly pointed out the grease didn't 'leak out'. Remember, gravity wins.
