rob_engineer

I have a 2012 JKU with manual trans, 3:73 rear, with open differentials. I want to put the higher viscosity synthetic gear oil in the rear as recommended by jeep because I tow my toy hauler with the jeep. The royal purple says it is good with limited slip without the addition of the limited slip additive. So here is my question, if it says a limited slip additive is not needed when used in a limited slip rear, do I need to be concerned using this fluid in my open diff rear?

gunbo75

No its ok. Royal purple is a good oil

ronjenx

Lots of synthetic gear oils that say no need for the additive in a limited slip, work just fine in an open differential.

ConroeJK

Nothing to be confused about, I just got through replacing my diff covers and fluid. As I normally do, I over researched. I ended up using Mobil 1 75w-140 (mixed with some dino 85w because I ran out of the Mobil 1). This study, sponsored by Amsoil, was an interesting read (http://www.freeoilhelp.com/product_info/g2457.pdf) and consistently scored Royal Purple very low, it was enough to make me want to choose another brand. Also noted was how well Mopar fluid did.