What Gear oil do I use with my Eaton Posi??

[Mean88]

Says it needs Mineral based?? What does that mean??

 

[89MustangGX]

Sounds like it means NOT synthetic.

 

[Mean88]

do I need to use any friction modifier like the trac loc clutches need?
Thanks
Ted

 

[89MustangGX]

I'm not sure -- I want to say yes, but have never used an Eaton. I believe the idea is the same as the stock trac-lok type with clutches that slip, so it would sound right, but better double check that.