2001 Legacy wagon AWD: drive train "hop" at low speed turn.

[josh & chris]

Howdy ! this phenomena occurs randomly, though with increased regularity, when you are turning at low speed - like turning into a parking spot. Left or right turn. Could it be a U joint or the differential? I am not as familiar with this type of drive train (AWD) and I live 3 states away from the car as my son is using it. Any thoughts? Does not sound like common noises that a CV shaft makes and I recently inspected all the boots and they were in good shape.... Any ideas?? Thanks, Josh & Chris