This might sound stupid, but have you checked the spare tire? Mine was making a solid "clunk" type of sound... I looked for 3 days trying to figure it out and reached under my WK and moved the spare with VERY little effort. I tightened it up and the noise is gone.
[B][SIZE="2"][B][FONT="Fixedsys"]2006 WK Laredo
Rocky Road 2.5 Lift
BFG T/A 265/70R17
American Racing XD Addicts, 17x9
Rola Roof Rack[/FONT][/B][/SIZE][/B]
[B][SIZE="3"][FONT="Fixedsys"]eat, drink, and be merry... for tomorrow, we die.[/FONT][/SIZE][/B]