What kind of oil goes in a Lockright Diff and What goes in a L.S.?

[Kirby N.]

I getting gears in next week. I got some 80w-90 for the rear end. Will that work? What kind of additive do I get fot hte L.S.? I did it once, I just can't remember...

Also, I am getting a Lockright for my front end, but it is used. What oil goes in these? Is the LS additive OK? Thanks!

 

[NOTAJP]

I presume you have the factory LS from Ford. Just about any Limited Slip additive from Napa will work just fine. The Lockrite's don't require any additive. Full lockers and box lockers (lockrite) don't require any special lubrication. Limited Slips need a friction modifier just like an auto-transmission due to the clutches. I have found that my Detroit locker has improved it's mannors 10 fold by running synethic oil and Power Punch diff additive.