Maybe that is what it is. If this is the case, that can be remedied fairly easily. I have noticed that when I have passengers in the back the rear axle seems to bottom out too easily when one hits a transition in the freeway surfaces. I will look into this.
Thanks, and by the way, that website is awesome. My brothers in Utah both have highly modified Broncos, which they take to Moad with regularity. I sent them the pix of the Xterra with axle articulation that was extreme and the parts list to go with it. They are all for modifying my truck now. To bad it is a daily hauler for the time being. Maybe later...
Have a good one, whatever it is...
eti engineer