What gear oil should I use...and how much?

[imq707s]

How much and what kind of gear oil do I need for the front greacase on my 1998 Mountaineer with 5.0 / AWD? Do I need to add any special additives for the limited slip differential.....does this thing even have limited slip?

Thanks

 

[jimbo74]

not sure if the rear end has limited slip or not, but the front end surely doesnt have a limited slip differential so no friction modifier will be needed up there.....

 

[bmxking5]

If you post your axle code (in the driver's door) then I can let you know what your gears are and if you have a limited slip.

 

[snocross1985]

If you use a synthetic gear oil, there is no need for any friction modifier; limited slip or not. I have Mobil1 in my limited slip rear diff, no friction modifier, no problems. Just an FYI.

 

[aldive]

Mobil 1 or Amsoil ( which I use ) with no modifiers.

 

[Mbrooks420]

I think all AWD's are 3.73LS. At least all of the ones I checked were. I looked at at least 30, and checked all the ones I was interested in, probably 10. You should have the axle code of D4.

 

[Bronco638]

As for "how much", fill so that diff fluid reaches the bottom of the fill hole (you can use your pinkie finger to check). It'll probably be somewhere around two quarts (+ or -).

 

[Eneurb]

Most newer diffs will have two tags on them... one to identify the diff, and one to tell you which fluid to use... 1997 should call for synthetic 75w140 (I add modifier to it) but more recently Ford has switched to synthetic 75w90 for better fuel economy (and I still add modifier to it)