Front Axle Lubricant

[Robert]

Your manual should call for 80W90 conventional gear oil in both axles. The only time it calls for 75W140 synthetic is if you have a V8 or limited slip. Going synthetic would probably be of some benefit, but I don't know what the affects of changing lubricant weights from what Ford originally specified would be on the differentials.

 

[Fischer]

Yea, I am going Synth. Amsoil.

I think that I will just run the 80W140 in both. I suppose it wont hurt anything.