Thanks for the discussion here. You saved me $80. The guys at the oil
change place tried to pull this one on me this morning. Showed me some
plug covered with gunk and small metal shavings. It's the second time
they've tried to get me to have the service performed. Luckily, I pulled
out my owner's manual, and told the guy I'd see what Ford recommends.
Hmmmmm, didn't see a thing in there about rear differential fluid. I told
him I'd do some research and have it done next time if I thought I needed
it.

Time for me to find a new place to have my oil changes done!

Thanks,
Dawn in South Carolina
2000 Ford Explorer XLT