What type of rear differential fluid does the 2010 ford f150 use?

The 2010 Ford F-150 uses SAE 75W-140 gear oil in the rear differential. This thicker than average oil will give better protection for the gears in Your rear diff. The rear differential is a small housing and with the rotating gears it can get hot inside it. A thinner oil would break down and not provide protection to Your gears like the thicker oil does. If You happen to notice that there is fluid leaking from Your rear differential then I recommend that You replace the main gasket that seals it. You should also check the fluid in Your diff at least once a year to make sure that it is free from signs of debris or damage that could hurt the gears.