Have a look at the balljoint first, visual check, look for busted rubber, grease escaping, oily/ wet substances around the balljoint where it was leaking for awhile. do the 12 to 6 check and the 3-9, listen and feel for knocking, jam a pry bar in if you can and prise it up and down, look or excessive movement and knocks. replace both. im going to do mine soon both, ive no knocking but ive seen failed balljoints, wheel falls in on itself.