gear lube for front & rear end

[Jeffcosta423]

What grade of gear lube & brand is best for rear end on a 4x4 model 05' 350?

[jesilvas]

Manual should say what weight. But if it's a D80, like mine, it takes a synthetic 75W-140. I used Shaeffer's.
If it's a D60, I think it's just normal 75W-90, but I'm not sure.

[05 smoker]

i am running amsoil in the front and rear diff along with engine and tranny. just make sure its the right weight fluid and the right type. i think it requires a synthetic fluid in the diffs.
mike

[Jeffcosta423]

Im a huge Amsoil fan. Been using it in my trucks and construction equipment since 92'.
Thanks.....

[steelnc]

Just did mine and used mobil 1. 75-140. Put the Mag-hytec cover on too.