[Richard]

Bill,
I know I am dogpiling on your question to Chester. The two things that would cause one to have a hard look at alignment would be an tire wear patterns indicating misalignment, or a consistent pull to one side. Also too little toe can cause the front end to wander a bit.

Apparently the Dana Kirkstall 84 IFS suspensions are subject to wear on both the tie rods and the drag link ends. As Chester winced, the replacement parts are not cheap. Worn tie rod ends and worn drag link ends will cause free play in the on center steering which obviously contributes to wander on the interstate.

In my opinion, a giveaway to worn steering components is the steering behavior on a heavily crowned road as opposed to a flat road. If the coach steers behaves really well on a crowned road by playing the steering against the crown and it wanders on a flat road, that is an indication of worn steering components. On a flat road, you have to take up the slop in either direction to correct the direction. On a heavily crowned road, the crown wants to make the coach drift to the right, so you only are really steering in one direction to the left.