Join Date: Aug 2009
Location: Gaithersburg, MD
I can't tell how loud yours might be, so could be something different, but many of us over the years have complained about the "dreaded drive-line clunk". Usually taking off from a stop, when shifting into 1st and 2nd (or back down).
Dealer's response to those who complained was "it's normal". No-one that I know of has had a failure from this, so we all just live with it. If you search the fora, you will find much about this. The only 'cure' seems to be taking apart the rear diff and re-shimming the internals - not for the faint hearted.
Owner of "Campbelle", a Brazen 2008 GXP ... with mods piling up...