[onebluemcm]

Thanks gents. Ya, definitely no sound in a straight line, no clunking, no gear vibration, no noises that are constant or change pitch with vehicle speed. In the past it does seem to improve or disappear after the car has been driven for a while, I haven't put a time on it yet, but yeah, more or less thoroughly warmed up.

I just flushed brake fluid, in addition to the diff fluid, also changes trans fluid and engine oil, and am installing Bilstein PSS10 system on it, so I've had a close inspection of everything including wheel bearings, wheels, tires, all fine. The diff case did have some fluid on it, possibly from the pinion seal but also possibly from the drain plug, it was hard to tell for sure of the source, so this is something I'll be monitoring. The fluid that came out certainly didn't look like new, but it wasn't awful either, and no sign of water per se, but microscopically, certainly possible. I highly doubt there has been enough moisture in there to cause rust.

Also, it's garaged in an environmentally controlled space, so while it's sitting, it's not experiencing big changes in environmental temps/humidity.