Shaky steerling when I hit the brakes?

[91autoeclipse]

I looked at everything from ball joint to tie rod and rotors, rack&pinion....

I can't seem to understand what would be wrong? when i hit the brakes and the steering would shake..

The Rack and pinion makes a "thong" noise and it does move back and forth when the steering wheel is locked. is there supposes to have to some play in the rack&pinion..

the tie rods move a little too and so are the lower ball joints.

rotors are fine...

so what do you guys think i whould replace?

any help would be great...

tsua