OK got ya, I misunderstood you. We call both methods dynamic and computer assisted we called computer assisted.I thought you were telling me spin balancing will automaticly catch a bent rim every time. I can usually catch them the same way Paul does. I was kinda leaning to tierods and if that thing is rack and pinion the inner isn't a job for a back yard mechanic it takes a special tool. Lower ball joints usually don't cause a shake they just fail all at once if the inspection mechanic doesn't catch them.I had only mentioned a bent rim as 1 possible cause.Ford has a notoriously weak suspension system. They tend to give up handling and load capacity in favor of smooth ride.Not sure on the year you have but the 4X4 axle set up on the earlier models was poor at best.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!