Chevrolet: Thumping in Rear - 2003 Malibu LS

The Car: 2003 Chevy Malibu LS
Miles: About 60K
The Problem: Thumping sound in rear as if there is a knot on tire.

Have jacked the rear up and checked the run out on the tire which is
perfect. There is no knots, dips or anything evident that might be
causing the problem. I pulled tire/wheel assy and could not find
anything apparent that might be causing problem. I then pulled the
brake drum and checked it closely for a possible crack. Everything
looked perfectly normal. Anyone got any additional ideas what could be
causing this thumping that increases and decreases with speed change?
I'm going nuts trying to isolate this glitch.
Thanks in advance for any help and info you might share.

On Fri, 23 May 2008 20:45:46 -0500, "Don Young" <com>
wrote:
 

Don;
Thanks for the GREAT info and suggestion. I will give that a try and
see if I can isolate the problem. Will post back my findings.

Thanks again for your help, info and suggestions.
Tha RagMan