2012 Re-geared
JK Enthusiast
Joined: Jul 2009
Posts: 375
Likes: 0
From: Tampa, FL
also surprised you needed to go all the way to 5.13s for 35s. From my discussions with people on several different forums, 4.88s are fine even for 37's on the '12 manual. But hey...as long as you are happy, I am happy! What kind of rpms are you turning on the highway at what speeds, by the way?
JK Enthusiast
Joined: Jul 2011
Posts: 237
Likes: 0
From: San Antonio, TX
I'm running 35's with the stock 4.10 gears and I don't have any problems. If I were to regear it would be to 4.88 for 37" tires, but I don't see a need to change gears for 35" tires. I can possibly see a need if you have 3.21 gears like the OP, but I wouldn't do 5.13. I do a mix of hwy/city driving and if I had 5.13 gears, I'd be running my rpm's too high at the higher hwy speeds.
JK Enthusiast
Joined: Feb 2011
Posts: 348
Likes: 0
From: NJ
That's because his came with the 3.21 gears. If you have 4.10 you should be good to go. I hope to eventually get 35's for mine as well figuring I'll be fine with 4.10 & 6 speed.
JK Freak
Joined: Jun 2008
Posts: 812
Likes: 1
From: Great state of Arizona
Just got my 2012 JKU Sport back from getting re-geared. Went from 3:21s to 5:13s. Wow! What a difference! Still in the break in period, so I'm taking it easy but it's a major difference in responsiveness. I bought the AEV Procal to deal with the limp mode issues I had read about, but I haven't had any issues. I'm going to use the Procal to flash the computer for the gear change and new tire size anyways, but I'm curious if anyone else has re-geared a 2012 and what their experience has been.
Thanks
JK Newbie
Joined: Sep 2011
Posts: 73
Likes: 0
From: Wind Gap, PA
That's what I thought as well. 4.88 is about right for normal use. I can see top gear being a problem with larger tires however, but gears would be low on the list.
JK Freak
Joined: Jun 2008
Posts: 812
Likes: 1
From: Great state of Arizona