jeepairforce

X2 -

If you're going to buy 37 inch tires though, DO IT RIGHT. Get 4' inches of lift, drop in a dana 44 front (I recommend a Prorock 44), & don't get wheel spacers(get new wheels entirely). You will ABSOLUTELY HAVE TO get new gears (5.13, I know this because I drove 37's on 3.73 for 5 months), you HAVE TO get a new rear tire carrier as the stock will literally fall off, & you will also need to get your speedo re-calibrated(I believe in some states it's the law on the speedo). Front drive shaft is also another good recommendation.

Most importantly though, TAKE IT OFFROAD! If you're going to have a Jeep, JOIN THE CLUB. Literally... go out with a friend who knows offroading and see what you are missing. You own a piece of "jeephood" which not many people understand. Only jeepers will stop to help another jeeper. Jeepers climb mountains together and have a beer afterwards looking down on all the other inferior cars and trucks on the freeways below. Jeepers build, create, design, and modify their jeeps together. We share ideas, tips, and mistakes we've made so others can benefit. But you won't understand the full truth of owning a jeep until you take him/her offroad and see the magic happen.

OR, you can throw 37's on and park it with one tire on the curb

jerseyjkredneck

Alright u guys convinced me to run 35s

renpia

Wow, that is horrible. Did you use a programmer to reset your computer to the new gear and tire size change? I bet that's part of the problem. I run 37's on 3.73 and get 14 mpg running a Superchips. 10 is just unacceptable with 5:13's. Must be something wrong.

untold

I know this won't help much, but I'm going to throw it out then. I'm running 35 mtr on stock 3:21 with a 6 speed. I'm getting about 16 to 17 mpg mostly city and little to no freeway driving.
I had a hand full a chances to get regear and I can't bring my self to do it. Yea, the jeep dosent really get up and go ( it never did ), but it works well for the plans I have for my jk.

I'm also running a 4" lift with a 1.25 body lift too.

jeepairforce

The upfront cost of regearing is big, but the benefits are huge.

1- If you regear, more than likely you will gain 2-3 MPG. If you're averaging 12-15k miles a year that could save you $425-$525 (Based on $3.50/gal and 13,500 miles) every year. In 2 years you pay off the cost of gears just on savings in gas.
2- Your Hi4 will perform better
3- Hills become effortless again
4- If you ever need to sell it, having the gears can be everything. Trying to sell a 3.21 gear jeep on 35's to anyone could be tough, especially people who don't understand gearing. (selling a jeep is a tragedy tho, so don't ever do it)

just my .02

Ralphie

I just had my Jeep worked on at ForTec Roswell Georgia. I have a 2010 JK Unlimited. I put 37 Mickey Thompson, 4 inch lift, Front and Rear Heavy Duty DriveShaft's, Dual Steering Stabilizer and 5.13 Gears. Re-gearing was the best change out of all the changes. No more up and down going up a hill. If you run 37 inch tires 5.13 is the route to go. Going down it took 1 & 1.4 tank of gas. Coming back 3/4. More Power than ever. Go 5.13.

txdiamond17

I am fixin to get to modding my JK. I am on the fence on which tire size, but with a 6sp and 3.73's I think I can bear it for a while. I am trying to figure which gears I need 4.88 or 5.13. Can the D30 accept 5.13? I need to find a good shop to do the regear in my new area. Anyone know of a good shop in the Little Rock or Memphis area? I will probably only go to 35's, but I'd like to gear for either one if its possible. I am itching to get it done and USE it in all the spots I keep reading about in Arkansas.

jkhounddawg

I'm rolling dirty-7's on my stock geared D30. It is not as bad as I thought it would be, however, I do plan on regearing and getting a pr44 whenever the $ becomes more available, Air Force dont pay me enough. its auto btw.