Yep, Chevy 1946 3800 dually. Upon visual inspection the 3 u joints look fine; at least no obvious signs of shearing. Should I attempt to remove them and test individually? While inspecting I did notice:

A large coating of fresh grease around the transmission.There is also a "grease spray"(?). Look at the side of the battery and above the U joint. Possible culprit, another issue or no problem?

1946 Chevrolet 3800 1-Ton

In the Stovebolt Gallery
More pix on Picasa

I understand computers and I like them, just not in cars.