Sounds like the tranny went? Never had a Savage bhut that is the only logical place it could be---or if it has a set screw for the dogbone to tighten to the output shaft on the tranny I would start there.
yes, i would go over each and every screw on the drivetrain first and make sure everything is cinched down tight. then i would take a look at the diffs, even though they are most likely not the problem. then take off the tranny and tear it apart.