Clunk in my steering shaft..

my steering wheel shakes pretty bad at certain speeds..usually when you get going pretty fast.. I'm replacing struts, but I also noticed,
when the car is off and the wheel is kind of locked, that when you move the steering wheel back and forth, you hear a clunk.. and it seems to be coming from my steering shaft..
seems like it has some play at the lower u-joint looking piece..i kinda felt it and it sounds like thats where the small clunk is coming from..
but you can't hear it or it doesnt seem to do it when the car is on and the power steering kicks in...
But would this be possibly why my wheel shakes terribly at certain speeds?? i really didn't wanna have to spend the money on a new shaft!! ahhh

also my steering rack bushings are shot..i think they are 2 piece..
do i have to remove the whole rack to get them out??? Or is it pretty simple..somone please help me

adding to that, when sitting at idle, my steering wheel SHAKES LIKE A MOFO! like pretty bad.... i do have pretty new poly. motor mounts..
and the shaft is NOT hitting the header...
is this normal for the wheel to shake that bad at idle??
or is that a key to something..