I had asimilar problem on an Aerostar. Was fixed by lubricating all of the chassis points that i could find. I had one, brand new, ball joint that i had installed with the stock amount of lube, apparently not enough.
I've never known a rack to groan like that, but maybe. The sort of sound he is describing seems more like metal on metal under stress, like a ball joint in the socket, or control arm attachment.
just my
