The vibration sounds like its happening at speed and could include any recipriating mass. The brake rotors are a definate possibility. In the good old days we used to concern ourselves with out of balance hubcaps. Sad but true.
The road force balance eliminates things that a standard dynamic balance doesn't consider like sidewall flex, cord variation, out of round wheels etc. The quality consious dealers use them with great success.
Last edited by Rocket; 01-29-2003 at 08:35 AM.