Could be a few things, first thought is loose torque converter to flex plate bolts.
second thought, worn bearings in the bottom end.
what is the mileage? How is the fuel consumption.
third thought is that it could be in the transfer case input shaft or the transmission input shaft.
it is definately a moving part that has to take the load when you start off.
but just to be safe, check all the shields and other things that are bolted in and around the area you hear the sound.
'06 XK 245/70R17 Nitto Terra Grappler, Thrush 30" glasspack, My Custom LED taillights, Euro fog/bumper light mod, LED accent lights...working on more to come :-)
Last edited by ManVan37; 07-10-2011 at 07:03 AM.