i figure i'd update this thread.
it was the stupid spare tire causing the thumping!!!!!!!!!!!!!!
i know i initially thought it wasnt but i tested again with the spare tire out and no more thumping. talk about chasing ghost issues..
trouble is no matter how hard i tighten the spare tire it still moves around. why doe it even have this cut where the bolt sits allowing it to move left and right? it doesnt bother me now that i know there's nothing serious but i am curious if i am maybe missing a piece or something to really make it stay in place during hard turns?