What do you do to get it to produce the "knock"?
-does it happen at a stand still while turning the steering left or right
-while driving and turning
-going over bumps, while driving straight
If it is happening while turning the wheel, the easiest thing to do is to have someone turn the steering
(with vehicle parked :doh

, while you listen and hold each steering component, one at a time. You should be able to hear, see and most importantly feel clicks and pops in the track bar, tie rod, drag link, etc. You may even be able to do this with the sway bar.
If its happening under driving conditions, you may need to walk along side to narrow down either suspension, control arms, or sway bar.
Not trying to insult anyone's intelligence, but look for witness marks or shiny spots where parts are contacting places they normally wouldn't.
Good luck, keep us posted :thumb: