I have a small knock that I can feelin the steering wheel, when say going over speed bump. Just a slight extra knock like a something is loose. What are the possible reasons?

Tie rods
Ball joints
Center link
Pitman arm
Idler arm

I am planning on rebuilding the front endand adding the 2 inch re-indexed keysnext weekend. I am already planning on replacing the ball joints and control arm bushings with poly ones at the same time, but am wondering if I would need to get into the steering stuff to get that knock out of there. So I wanted to see if anyone else has had this or any tips to see what part is actually doing it.