TheRhino

What gear oil should I put in my 1993 with an 8.8" open differential

jayber

75/90 or 75/140 if you do lots of towing.

VickMacky

I used Valvoline 75/90 with a bottle of friction modifier (if you have a LS diff).

qdeezie

Depends on your budget and what you're doing with your truck.

If your budget is tight and you are not doing any towing or hard driving: 80w-90.

If your budget is tight and you are towing or hard driving: 85w-140.

If your budget is not tight and you are not doing any towing or hard driving: 75w-90.

If your budget is not tight and you are towing or hard driving: 75w-140.

As far as brands are concerned, use your favorite brand or whatever brand you're curious about. If you have a brand in mind, but would like opinions, come back and ask us about it. I'm sure one of us has tried it before.

TheRhino

Thanks! I have an open differential btw for people wondering

qdeezie

You don't need anything special for an open diff. Just your favorite brand of gear oil. Just depends on whether or not you're towing or driving it hard.

TheRhino

I drive it hard lol

redneckfordf2502002

So for limited slip diffs you need friction modifier?
What about for my truck with LS front and rear do I use friction modifier?
Trav

Crownman

If the diff is a clutch type LS, no matter which axle it's in, then yes, it needs friction modifier.

redneckfordf2502002

it is the original ford LS so not sure if it is clutch type or not.
Trav