which gear oil?

Which is the best gear oil to use in an A4 with fresh 3.73's (just broken in)?

Thanks

Joe

If you have an Auburn differential, regular gear oil is what you want. Synthetic is too slippery:

From Auburn's site...

2.) What kind of oil should be used with an Auburn differential?

It is important when installing Auburn differentials that a high quality, non-synthetic 80w90 GL-5 oil, treated with GM or Ford limited-slip additive (also known as friction modifier) be used. Three ounces of additive will treat one quart of oil.

I have an Eaton in my Moser 12 bolt. They also require non-synthetic conventional gear oil.

It is a SLP differential, I believe.

SLP nameplates other peoples products. Call SLP or check on their website for an FAQ.