Fluid weight difference - Owner's Manual vs. Motorcraft
So I'm trying to order differential fluid for both the front and rear diff and I'm getting two different numbers. My owner's manual says to use 80w-90 front and rear and motorcraft.com says to use the following:
"Part Description: (Motor Oils And Lubricants Usa Usage); Hypoid gear lubricant - ""Use 75W140 synthetic oil ONLY'' "
I know this subject gets beat to death, but I wonder why the difference in weights? Did Ford come to some new understanding?