Before you go much further. Remove your differential cover. Based on your symptoms, your pinion bearings have probably failed. Take a look at my webshots page and you will see what I mean.
SWEET Sergeant At Arms: Old Dominion Stovebolt Society BUNS?!?!?!Where we're going, we don't need no buns..... 1950 GMC 450 1951 Chevy 1/2-Ton The GreenMachine In the Stovebolt Gallery