It's a clunk. It comes from the rear, driver's side wheel. Possibly both rear wheels? Makes it's sound when going over medium bumps. It sounds like the axle is hitting the limiter bump stop. Probably was over a year ago but I put new springs, added air bags (for when I load 'er up) and put new shocks on all the way around. I think I originally wondered what the sound was and noticed the sag and measured the drop of my 4R, so upgraded those things and now have a much nicer ride and definitely higher (2-3 inches) but notice I still hear this clunking over bumps and now it's annoying since I know the stops definitely have clearance now.

What it isn't -

1) doesn't seem to be the exhaust pipe. It is close in clearance over the rear axle but I've heard a tailpipe hitting before on another vehicle and this doesn't sound like that.

2) not the spare tire. Honestly thought I was onto something when I removed it and found it was light on air... sooo, thought maybe the low air was causing the wheel which was wound up when it was full, to rattle around a little under there over bumps due to lower pressure in the tire.

3) even though shocks are only a little over a year old, lifetime warranty so went ahead and figured a faulty shock and replaced.

4) all suspension parts "appear" to be intact. no broken parts.

5) for sh*ts and giggles, I have tried both extremes for my air bags... completely deflated and completely maxed out - no difference in noise.

Soooo, ideas of what the noise is or some processes I can take to continue ruling things out? Unfortunately the only way to test it is to drive and run over bumps... Seems a suspension issue. Hoping for a quieter ride. This noise has not been with the vehicle the whole time I have owned it.