How much oil is required in a rear differential for a 2005 Ford F-150 9.75 inch differential?

The 2005 Ford F-150 with a 9.75-inch rear differential typically requires about 2.5 to 3 quarts of differential oil. It's important to use the recommended type of gear oil, which is usually 75W-140 synthetic for this model. Always check the owner's manual for specific guidelines and ensure the differential is filled to the correct level.