E450 Rear Diff Fluid

[CHS]

Reference a 2018 Ford E450.
Wanting to change my Differential fluid in a few weeks. Manual states
SAE 80-90 but watching a YouTube video and they stated that Ford now recommends 75-140.
So why does it NOT state this in my manual. From what I read, this is been for a while now.
What are you all using? I see Amsoil has the 75-140 synthetic oil at a good price.

[Pillbox]

Fomoco updated there oil. There oil IS $$$$$
Youtube it

[CHS]

I ended up buying Amsoil 75-90 severe gear oil. Actually cheaper than motorcraft.

[ducksface]

Do it outside.
Few things smell as bad and stay in your sinuses longer.

[lwmcguir]

Great advice by DF

I always used synthetic in my F350, F550 pickups ever since it was available

They all had the heat exchanger plates and if you don't have then you have some extremely hot temperatures when getting down the road on a hot day