Differential fluid the magazines are recommending

[JS27N0B]

I use nothing but synthetic gear lubes. If the factory recommends it it's got to be good. We don't see failures on units used for pulling like we used to either.

[bb71challenger]

Only ever had one sure grip unit go out and that was because I was broke and used two different size tires on the back. Other than that the only failure was when I used Mobil 1 full synthetic on my Challenger. The sure grip unit went out after about 6 months. Dinolube and additive for me from now on.