Fluids?

[mikeexpedition]

So I think I might need to change my differential fluids since it appears the seals have never been broken. Autozone is telling me I need about 3 quarts in front and back but I'm not sure if I have limited slip or not (apparently I would need an additive if I do) and they are saying synthetic in the rear. Synthetic is $60 just for the rear. Do I really need synthetic?

I have a 2001 expedition Eddie Bauer with 176k miles.

 

[Exia]

So I think I might need to change my differential fluids since it appears the seals have never been broken. Autozone is telling me I need about 3 quarts in front and back but I'm not sure if I have limited slip or not (apparently I would need an additive if I do) and they are saying synthetic in the rear. Synthetic is $60 just for the rear. Do I really need synthetic?

I have a 2001 expedition Eddie Bauer with 176k miles.

If it came from the factory with it I wouldn't change the fluid type keep it the same, yes its costly but once you change it you are good for 100K or more miles.. It doesnt pay to be cheap when maintaining a vehicle especially 4wds

 

[splintrcel]

I have to swap my rear axle seals and it is gonna be $75 to refill that diff casing but i am gonna stick to what ford put in rather then chance something else. Diffs arent cheap.