Hey guys, my 06 320CDI (250k miles) has a noise in the rear. I got on the road from Savannah Georgia yesterday headed home and all at once, I started hearing a roar/grind sort of noise coming from the rear. As I drive home 4 hours, the noise would come and go with no particular relationship to any behavior while driving. If I could keep the car at a steady state (not accelerating or decelerating) it seemed the best. About half way home, it started a whining/whistling noise when I would slow down for a stop. Jacked it up this morning and got both rear wheels up and let her run in drive. I can't increase the speed b/c the computer seems to be holding it back to idle while up in the air (anti slip maybe??) Both axles and joints seem to be ok - can't find any play in them and there is nothing noticeable going on. After a while I start to hear the noise (although not that bad at idle speed). I can hold either rear wheel to make the opposite one spin and the noise seems to be the same. In essence, it appears to be coming from the differential. I put a steel rod up against it and I can hear the noise. From reading some forums on this site, I see that some are saying that I probably need to change bearings. I have NOT changed the lubricant - I didn't realize I should have. So, I suppose I'm looking for some validation that the issue is what I fear and the best course of action. I'm mostly a DIY kind of guy so I may take on whatever rebuild project myself although I don't have a lift unfortunately. I appreciate advise from those who have experience on this issue. How to rebuild, rebuild kit, any special instructions, etc. Thank you guys!!