Auburn differential

I have a '98 SS with the Auburn differential. The car only has 10,500 miles, so I've not needed to mess w/ the diff much. The recommended fluid is 80W-90 mineral base oil w 2 ounces of GM Lubrizol. Can I run AMSOIL 75W-90 synthetic in this diff, or am I asking for trouble? Why or why not? Do I still need the Lubrizol w the AMSOIL? Do I need different gasketing materials? If I can run the AMSOIL, how far does it extend the change intervals? Thanks.

I have heard that you are not supposed to use any synthetic in the Auburn Differential. someone on here posted a link to the SLP site and it said not to use synthetic.

i have to second that, i bought an auburn pro diff brand new before and found that out after i made the mistake. calling auburn confirmed that synthetic is to not be used in their diff's.

Originally posted by chevy qc
i have to second that, i bought an auburn pro diff brand new before and found that out after i made the mistake. calling auburn confirmed that synthetic is to not be used in their diff's.

Do any one you know why you shouldn't use synth? Did Auburn tell you? Thanks.

An Auburn is a clutch style posi, and if the fluid is too slick it is prone to singletrack.

Originally posted by chuck
An Auburn is a clutch style posi, and if the fluid is too slick it is prone to singletrack.

Thanks for all of the posts.

Crap!
Now I have to change the fluid out of my Auburn. I used synthetic to fill mine up.


Thanks for the info guys.
Milo