2002 Sport Trac

[410Fortune]

Most stores carry a Lucas brand limited slip additive
It helps prevent the fluid from foaming
It works great with or without a limited slip traction device

Gale banks (I watch a lot of Gale banks videos) has some excellent information on the web about what happens inside a rear differential and why the additive is always a good idea

 

[Fordtruckfan89]

Gale banks is a genius. Ford has the limited slip additive too. I usually get a couple bottles of that and Valvoline synthetic 75 140

 

[dvdswan]

Is it limited slip?

Yes, D2 axle.

Thank you gents.

2.6 qts. plus additive or 2.6 qts. with additive?

 

[Fordtruckfan89]

I usually put the additive in first and fill it up to the fill hole, let the excess run out. Check vent hose while you're down there.

 

[410Fortune]

Like he said
Additive first otherwise you run out of room

Most full synthetic gear Lube includes an anti foaming agent… but I still add the limited Slip stuff for good measure