I want to change both the front and rear differential oil on my 02 superduty. How many quarts of oil do I need to buy to do them both. Front is a Dana 60 and rear is a sterling 10.5

 

Dana 60 front axle: 90W gear oil, 2.7L or 5.8 pints or 2.9 quarts

Visteon/Ford 10.5" rear axle: 75W140 synthetic gear oil, 3.3L or 6.9 pints or 3.45 quarts + 8 oz of Friction Modifier type XL-3 if you have limited slip.

Transfer Case: Mercon ATF, 1.9L or 4 pints or 2 quarts.

 

Ford says 3.45, but when I changed mine I seemed to get every bit of 4 quarts in the rear of mine, rear took 75w-140 syn.

 

I thought Ford changed the specs for the front from regular to synthetic?