Rear End Gear Oil

[Oliver 550]

I have a 2008 F350 that is leaking a little rear end oil. I pulled the square plug on the back side half way up the diff cover and found it is a inch or so low. I assume I need to bring it up level with the bottom of the hole. What oil did Ford originally use in these trucks? I have the dually with 3:73 gears.

As soon as I return from this trip I am going to take it to the dealer and have it fixed.

Any help would be appreciated.

thanks

[greasltn]

There should be a tag on the rear axle that tells you what fluid. If you have the 10.5 inch axle it takes75w-140. If you have the dana m80 it takes 75w-90.

[2x6 bulldog]

Make sure and use synthetic fluid!