9 in detroit locker best gear lube to use

[speedy30]

What is the best gear lube to use in a 9 in detroit locker. I have read not to use synthetic That's moser said.

[TA98]

Lucas non synthetic or maybe the standard valvoline. Im not sure about those but i know Truetracs youre not supposed to use friction modifier and i know some gear oils come with that already in it.

[2002ssslp]

I like the standard Valvoline 90w-130 without a modifier for that combo. Some diff's don't need it like the Torsens which are all gears and no clutches.

[Supershafts]

Kinda depends what you're doing, there is time lost in differentials

[Firebirdjones]

Yep, if you are racing the car and looking for every last bit, run the thinnest slickest stuff you can in there.

On a street car, standard gear oil seems to be recommended by most of the gear manufactures. Even some posi units won't warranty their carriers unless you use a certain oil, which is generally non synthetic. A local shop here that has been building rearends for 35 years won't warranty his work if you use synthetic.

I've found those oils that are supposed to have the limited slip oil mixed in,,,,,isn't enough or it isn't actually in there. I've recently changed my gear oil with this "so called" limited slip mixed into the bottle on a couple of my clutch style posi's,,,,they chattered like crazy. I ended up dumping a bottle of Kendle limited slip additive in, and all was quiet.

So if you have a clutch style unit, grab a bottle of additive, because whats in the gear oil doesn't work, at least in the Valvoline oil anyway.

[speedy30]

thanks guys