Nasser is your guy talking about control arm bushings? Or maybe wheel hub bearings? Do you have Rockwell suspension? You need to look for anything that might be loose or have playing movement. The problem can be many different things like a bad drag link, even the brakes can cause this type of problem. I know about suspension but have not worked on a 1988 Newell.
I don't think the airbags would be the problem.
Here is a brake diagram that Sean had posted today on Rockwell
http://www.luxurycoachlifestyle.com/...ce-manual.html