I noticed my steeringwheel shaking a bit and when I would fly over a dip on the hyway the car would pull to the left but streighten back out and one day after getting gas I give er some and hit a dip the same time it shifted and almost lost control. got home checked out the front end and found the bottom bolt on the Balljoint was almost off.

http://www.automotive.com/used-cars/recalls/11/lincoln/ls/index.html

If you have a 2000-2001 within those build dates, it's a recall, go get it fixed, this could cause some serious damage. I believe if theres no structural damage they just tighten the bolt, if there is they should replace it.