Subaru Repair: 98 subaru rear end clunking, differential fluid, dry pavement

Question
When I turn left at slower speeds I feel the reight rear end click or clunk 3 times then it goes away.  It seems to be getting worse but I can't see what's wrong with it.  The boots are intact, and everything looks fine.  What could it be and could it be serious?

Answer
Jason,
A couple of questions. Automatic transmission or manual? What happens when you turn right? How are your tires? Do they all match - tread wear, brand? Have you ever driven a truck in 4 wheel drive on dry pavement? Is it a similar feel/sound? And finally, have you checked the rear differential fluid? Your problem may be serious, and it may not be. If you get back to me soon, I will try to get back with you soon also.