I've posted this on the truck side also, but I want to open it up to you car guys also. I just crawled under the truck, which is a B2B with 3-speed and fluid drive. I do not see any obvious issues with the u-joints. They're all dry and tight. The drive line doesn't have any play in it, in terms of side to side or up and down pressure; however, when I turn it, there seems to be some 'slop' in the differential. By that I mean when I turn the drive line by hand it moves about one-half inch before it engages and the axles turn. Also, if I grab the drive line and turn it vigorously alternating in both directions, I get the same noise I'm hearing when I drive it. It sounds like the gears in the differential are clanging together. I've never turned the drive line by hand before so I don't know if this is a new condition or if it's always been like that. It does seem to duplicate the sound I'm hearing. Whadda you guys think?