Interesting that you mention this, as I just went through this with another rattle. After the rebuild, I would get a low, but vehicle wide "hum", for lack of a better word, on deacceleration only. There was no origin to this hum and I couldn't figure it out. No vibration, just a hum - like the truck was humming a single note song. Fortunately, while nursing a bad ankle, I was driving with my foot pulled back against the seat because it felt better in that position and felt a very small vibration under my foot. Looked under the truck, under the location my foot was at and an exhaust hanger was resting against a cross member. Loosened it and moved it up a few inches on the pipe and problem solved.

At any rate, back to my problem at hand. This previous experience has helped me narrow the current vibration down to something most definitely mechanically amiss. It isn't harmonics or sympathetic vibration. I know what a vibration hitting the right "Trooper" note sounds like now (-;

What is the consensus for solving this problem? Shims? Double jointed carden driveshaft? Get suspension back to like new condition?

Thanks again for all your help,

NCDiesel