Hey I’m new here, just got my JKU about 3 weeks ago, the wife got a new 2019 JLU of course lol... I’ve built XJs and CJs been into jeeps since I was young.... anyways to the question
so I was trying to figure out if my JKs rear was open or limited slip.. I didn’t wanna take off cover so I did the rotate tire trick with both tires off the ground. When I rotated one tire the other did nothing and vise versa on the other side. Is this normal in JKs or what? Any help I’d appreciate
thanks

 

Did you look up your build sheet on MOPAR website. I believe a straight differential one wheel will turn forward and other backwards

 

This doesn't answer your question, but you should know that all of our Jkus have what is call brake lock differential (BLD) which is actually quite effective, even if you have open diffs like I do. Lots of info and some good videos exist if you search for bld.

 

True yea if the other tire went backwards I’d know it’s open but it does nothing lol.....I thought about brake lock but I didn’t know if it would work while Jeep was off and I was turning tire by hand

 

I believe you need to put the transmission in Park if an automatic or in a gear if a manual transmission.

 

Alright thanks I’ll give her a try

 

Brake lock will only work with the Jeep running because it is computer controlled.

 

Have you figured it out yet?

 

With a limited slip diff both will turn, with an open diff one will rotate in one direction and the other in the opposite direction. But this is only true if there is no brake drag at all, the slightest brake drag will stop one wheel from turning, limited slip will not be effected by brake drag.