My E150 XLT passenger van recently began to 'track' VERY slightly to the left as I drive. Seems like I am always adjusting the steering wheel to straighten it out. This all seemed to start when I rotated the tires. I have two year old goodyear radials ( 30K ). I did 'cross' the tires so that, for example, the former left tire is now the right front. Also, the brakes are only a few years old and when I stop abruptly, I sense no track to the left....so I suspect it is not the brakes.
Thoughts? Ideas for diagnosing?