Hi folks, newbie here, though have been lurking for some time-ha! I have been slowly building up my courage to talk myself into doing the birf job since I live in a small mountain town and don't trust any of the local mechanics. I've been searching like mad on the birf writeups and threads and I think I can do it myself! When I changed the front diff fluid recently, I noticed that there is some 'sludginess' to the old fluid when it drained. Since this was BEFORE I read about the bad birf/diff-soup, I put expensive syntetic back in. *ouch!* Question: If the diff fluid shows some birf grease contamination, but I'm not getting the deaded 'click-click' on hard turns, how urgent is the birf job? Can I wait 10k miles?