Tracking / steering issues

[bradleyheathhays]

My '11 Crown Vic has got 315k miles on it and I'm having some kind of tracking problem that I think is coming from the steering. If there's not much wind it drives straight down the road just fine up to about 60 mph. But if the winds up some, or if I take it up to 70, it's tracking characteristics start to get weird and unsettling. Rain seems to cause it to get worse as well. The feeling is not dissimilar to hydroplaning.

I got the wheels off the ground and pushed/pulled on all the tires..3 and 9 o'clock, 6 and 12. Back wheels were solid, and the fronts were ok when I did the 6 and 12, but on the 3 and 9 test the tires moved about 1/4". They didn't move easily say as if they were completely loose, but it didn't take all that much effort to get them rocking either. At each limit of movement there's a low grade thud that's coming from somewhere between the two wheels, pretty close to the center of the car I'd say. I don't know if the movement I'm seeing is normal, but the degree the steering seems to be unpredictable would seem to correlate to about the degree of movement I'm seeing with the 3 and 9 test.

Any ideas on where I go from here?