you should just be able to move the wheel left and right in quick motions not full turns and you should be able to hear and/or feel it. And GM is now replacing steering shafts, they have done away with the lube kits.
Overall grand prixs are the car I see the least in my shop for anything over than LOF's(oil changes).
Power steering racks go on occasion, I've seen one or two hub bearings, some problems with the DIC/6 disc cd player, if you have the onstar antenna right above the windshield in the middle of the car I've seen that cause a minor water leak onto the traction control switch causing your trac to be disabled and a light on the dash comes on (easy fix). I maybe have had like 2 trannys come in that needed replacement but they are few and far between. Like I said theres not much, those are only the ones I could think of.