Every now and then for the past month or so, I will feel and see the steering wheel shake while I am driving. I originally thought one of the tires had lost pressure so I pulled off the road and stopped at a service station. The tire looked ok, pressure was fine. Once I got back on the road, no more shake. When I got home, I pulled the front wheels and started pulling on everything in front. Nothing seemed to move at all. The sway bar connector bushings are cracked up so I have those ready to replace. I don't think that this would be the cause, though. The shake just starts while I am driving straight, not when I am entering a turn which would stress the sway bar. The tires are less than a year old, BFGoodrich 'all season'. Anything else I should be checking first? TIA.