i have an A4 and when i drop it down in drive or any gear other than park and neutral....or anything that will engage teh DS and rear i hear a clunk...not really loud not really low either.....is this normal or are my u-joints going? also everyonce in a while when im still rolling slightly i shift in to revese and i have the wheen cut to get in to my space it will go clunk clunk then stop....ujoints?

i have yet to get under the car to shake the DS so im jut looking for opinions....thanks
also would give me a good reason to install my LS1 aluminum DS and u-joints