I will check that e-brake linkage as you suggest. However the noise is quite loud much more than a rattle. I guess it would be like rattling that e-brake cross shaft in its mounts and getting that metallic clunking noise.
Here is another thing. As the day gets warmer the sound is not as frequent. Strange!
I did try the jack under the spring pad as was suggested and raising the spring the axle came with it. Given the diameter of the rubber bushing it would take a critical eye to see any discrepancy between it and the bracket.
I did find a source for those bushings. Steele Rubber has them but you must send back the complete unit so they can do it. Price $160.00 per pair. However at this point if it would get rid of the thump it would be worth it.
