Truetrac diff oil
 

I just got a truetrac installed on my truck and the oil used in it was Valvoline 80W90. It says limited slip on the bottle but does not say anything about having friction modifier in it. From what I've read you don't want to use synthetic or anything with friction modifier on the truetrac. Is this Valvoline in the link OK?

Valvoline? High Performance Gear Oil : Product Catalog - Valvoline®

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I think youll be ok.

Its a gear driven posi, it doesnt care what you put in it. I always used the cheapest crap 75/90 I could find with zero issues.

Here is a cut-away of a torsen or true trac type posi, you can see why it needs no additive, there is nothing gripping and slipping like a clutch/cone style unit.

Attachment 82077

I know it doesn't need anything special. Just regular mineral based oil. I was just checking if that valvoline had any friction modifiers in it because it says Limited slip on the bottle. If it does I'll probably swap it out for something that doesn't.

Yep, Im sure it does, and having it in there wont hurt a thing.