tkkim

hi I have 2021 jku sahara with 3.21..

and I just installed 2.5 rk stock mod w/ shocks , aev saverge wheel, nitto trail grappler 285 75 r17(34')

now i feel kinda lose of power..

so I'm thinking to regear..

4.56 or 4.88 which one is better? I'm gonna add some bumper and other mod. so..

and could you guys recommend me some good brand of gear? i just know superior.



PS - one more question. after install lift and heavy tire, when i drive little rumble road, I can hear some sounds that came from bottom. I think it cause from arm or some parts.. is it normal? cause from I installed heavy wheel and tire?

Sommer13

The rumble is probably just the tire noise. If you only hear it it should be fine. If you start to feel something then you might have a problem. And on the gears I'd suggest a 4.88 for you if you plan on extra mods with only 34's.

CajunTiger

x2 on the 4.88. I have Yukon's in my 2011 JK Wrangler with 33's. Going with 35's in a few months.

jeffj

The 2012 is totally different. I have a 2012 auto with 37's and at 70 I'm at 2800 rpm's. So be careful you don't wont to be at highway speeds and be at 3500rpm's. I could almost be good with 4.56 but I live in west Virginia and we have lots of mountains.

12HTownSahara

What gear Ratio are you running jeffj? I also have a 2012 jku auto and wanting some good hwy gears

jeffj

Sorry I thought I listed. 4.88's

E-Man

I've got a 2012 JKUR auto with 35's and am having 4.88's installed next week. The 4.10's were OK, but could be much better for stop and go city driving with hills.

powrsurg

FOr the 2012 4:56 is the same if you had an 07-11 with 4:88. 4:88 in a 2012 is the same if you had 5:13's in an 07-11.

If you do serious rock crawling I would suggest 4:88 otherwise if your just looking to get that torque back then I would get the 4:56. PLease let me know what you decide to do. Im interested in hearing the results.

Sommer13

Exactly why I'm getting 37's with 5.13 gears in my 2013 JKUR.

powrsurg

for 37's that is an excellent choice.