Uhoh! Thanks for the warning, I think!
If it serves as any repair-guy inquiry repellent, I thought I could fix my mystery oil leak by changing the differential oil, since it hadn't been done since... uh... 2004? Not only was the leak *not* the diff, I made quite a mess on the driveway while changing it... and it took twice as long as I thought it would. Oh well, that's life I guess.
Michael