[Savage_Messiah]

Noticed tonight that when shifting into or out of reverse (A4, open rear)that there's a clunk, the sound comes from the rear. Differential fluid was changed a couple months ago. Also if I have my left foot flat on the floorboard when I'm driving I can feel a bunch of little vibrations and shakes mainly when going over bumps, this has always happened tho so I don't think much of it. A friend is coming up Saturday and we're doing a gear swap, so I'm gonna be back there anyway. I did a search on camarov6.com boards but found no definite answers besides check u-joints, which I'll do later or tomorrow. If it is u-joints, how much is it to replace them? and can I do it myself, or do I need to take my car in? What else may it be?