Interesting chart. I have a 2011 Rubi Unlimited with auto, and 33" tires, and I have no performance problems at all, yet the chart suggests I should be running 4:88's instead of the 4:10's.

 

Thanks for the info. That clears it up a lot.

 

and basically what u do the front axle must do to the rear axle? 5.13 front and back? also whats a good brand to go with when dealing with gears?? sorry for stupid questions im new to this sorry!!

 

Yes, you need to regear both axles. (if for some reason you only regear one, you will need to pull the front driveshaft off until both are geared the same)

All of the gears are coming out of the same factories overseas, the different companies just package them in their own fancy boxes. Yukon probably has the best rep, but any should be fine.



There can't possibly be a one-size-fits-all gear that everyone is going to be happy with, so there can't be a chart that will be right for everyone. If you are happy with your gears, that's great. My guess, you simply haven't driven a regeared JK so you just don't know how crappy your performance is...

 

now my front end is a dana 30 im reading the a 5.13 setup wont fit so i also have to get a new carrier? im looking up carriers and there a lot of money and a lot of choices not sue what to go with. also some are electronically controlled, what do i go with? thanks for ur help

 

35s and 4.56 on a manny soon!

 

IF you have 3.21 gears currently, you will need a new front carrier. They are like $80 or so, not a huge dollar amount. If you have 3.73's or 4.10's, you do not need a new carrier.

The ones you are looking at are 'lockers', which will replace the stock carrier. Do you need a locker? If you do want a traction device up front, consider a $390 TruTrac instead of a $1000 selectable...

 

how do u know if u need a locker? whats the difference between carrie and locker?

 

Yes and if you went to 5:13's your mileage would suck even worse but your power would be off the charts. It all economy of scales- you trade performance for mileage with the JK. What do you plan to do with your JK?

 

Where did you come by that information? Looking at the charts that he is talking about, you can get an idea of where the freeway rpm's would be.

Auto, 5.13's, 33" tires = a bit over 2500rpm @ 70 mph. Not really screaming high rpm, is it? In fact, it's pretty much right where this engine likes to run, right? So he would hold OD better, with less lugging of the engine or constantly downshifting and adding another 1000 rpm. So his mpg's would actually improve, not suck even worse...