Have a 2012 JK UL with 6 speed manual. Installed a 2.5" lift and moving to 35" tires. Will not be adding much more weight other than occasionally pulling a single axle expedition trailer. Currently have 3.21 gears and know I need to move down. But how far? 90 percent of my driving is city (MD - no big hills/mountains) and I do not want to go too low. I know that's unheard of for some of you out there but... Local gear shop is recommending 4.56's but I am looking more toward 3.73's.

Any personal experience to help me navigate choosing the right gear set-up would be greatly appreciated. My Jeep is my daily driver. Really don't want to be shifting through to 4th gear shortly after leaving a stop light, but don't want to be significantly under geared as well (would like to use 6th gear on the highway).

Thanks in advance!:

 

If you are planning on 35s go 4.56. With stock size gears you will have to either go used or spend a bunch of money for new factory ones. Aftermarket gears and minimum install kits can be had for less than 400.

 

Switching to 3.73s is a waste of money for 35" tires.

 

I do have a set of stock 3.73s minus install kits with only a couple of miles on them. Not my main concern however, want to be satisfied with the direction I go.

Any other opinions out there?

Thanks for the information.

 

3.73 is worthless. My 2013 2-door came stock with them. When I had 35s, it was miserable. I spent more time in 5th gear on the highway than in 6th (and I'm a lot lighter than you).

Don't get caught up thinking that a numerically lower gear ratio means better mpg's. You'll spend a lot more time shifting and not in 6th gear, that it will hurt your mileage.

Anyway, I don't think you will find a single person who would say regearing to 3.73 makes sense. 4.10 would be an absolute minimum if you are going to. 4.56 is nice, especially in the off chance you add weight, tow a trailer, or go to 37s. I'm running 4.88, 37s, and my Jeeps is heavy now. Just did a 700 mile trip and averaged 17 mpg, and half the drive was through the PA mountains. It's all about finding the most efficient RPM range.

Don't fear the gear!

 

Any thoughts on lockers when the gears go in? If so, and if you talk your self into 4.10's, (or even 3.73's), start looking around for a set of take-off rubicon axles instead.

 

Totally agree with you, especially with a manual. I'm running 4.88 w/ 35's and it's on the edge of comfortable driving. If he doesn't have any plans on going to 37's, the 4.56's would make nice a daily driver.

 

Based upon all of your feedback I have decide to go with 4.56 gears. I have no plans to move to 37s and looking for just a solid DD. Part of my hang-up came from owning and working with rear wheel drive muscle cars. No 4WD Jeep experience. There are marked differences between say 3.23, 3.55, and 4.11 rear ends. I guess not as much with Jeep gearing.

Just don't want to drive a rock crawler on the hwy to work each day. Again, thanks for the feedback.

 

In the process of driving back across the country from Moab. 2012 6 speed manual with 4.56's and toyo 37's. This combination has worked perfectly. With 35's I never had to down shift out of 6th unless I was going under 50. I always felt it was a little on the over geared side for 35's.

 

Don't waste your money on anything less than 4.56s.