Cardan Joint????

[causethechicksdigit]

Hey everyone, i posted in the driveline section a few days ago with no answers so im going to try here to see what i get. Iv had a bad vibration for a few days now and its getting worse, it felt like a bearing to me so i guesses that it was a hub assembly bearing so i tried locking my axle up and it still vibrates, the only way i have found to cure it is to actually engage the transfer case. So my question boils down to how do you actually inspect the cardan joint in the rear shaft because that the only thing i can thing would be the issue at this point, or is there anything else you can think of that could be the issue. The rear u joint at the axle is new also.