What oil in rear diff?

[Dre]

Time to change oil in the rear differential. Wondering what I should put in there... I've got a Powertrax locker installed.

thanks for your tips.

 

[rookieshooter]

http://www.royalpurple.com/gear-oil.html

or Amsoil

 

[gavin]

Ford recommends 75-140 (or is it 80-140?).
but shouldn't be any troubles using 75-90. I know that's what aldive uses.
Myself, I was putting in 1 quart of 75-140, and the rest was 75-90.

 

[manaen]

Whatever you get, it's probably worth going full synthetic