After missing out on a chance to go to Moab with some friends this year I decided to save up and plan for next year in advance. Problem is I was thinking that I should get my gears changed. I have been told it would help with the ride on trails and gas mileage. Is this True? if so is there a piticular brand I should look for? and the dreaded question that gets asked over and over is what size would work best?

Here is what I have
2007 JK 2door
Automatic transmission
tires are a large 33s
engine has Super chip flash paque and Airaid intake and Powerair throttle body spacer.

Please I know I might com off sounding dumb but could use some real help and sugestions.

Thanks

 

I have a 2010 JKU sport with 35" tires, actual size 33.75" mounted

I have Yukon gears, 5.13, Flashpaq, and muffler. Run the 87 octane tune.

The gear ratio is just about perfect. A lot of mechanics who don't work on jeeps will advise (at least around here) a higher gear ratio, but that is because they are unfamiliar with the Jeep auto tranny and overdrive. You can go lower, though if you have a D30 you might conside 4.88 to get a larger pinion up front.

My MPG went up after I re-geared, probably because the vehicle is not downshifting as much and not working as hard. Only went up 1.6 MPG, but still a gain.

The Yulkon gears set up really well fwiw, I imagine other brands might as well but am pleased with them

 

Regearing will help your "performance" on the trail. So will a lift and bigger tires. But all this takes you in the oppsite direction for gas mileage. The manufacturer ships their product from the factory set up for good gas mileage. To make this rig more eco friendly, you would have to do mods that would make your rig less trail friendly.

 

Got a lift (4inch skyjacker) and large 33inch tires. But stock gears. I was told that with stock gears on the lift and tires engine has to work harder. I was told that gears would help with that.

Thanks for the reply everyone

 

The stock gears work great with a stock Jeep. But adding a lift and bigger tires puts extra load on the engine. Re-gearing will help put you back to the stock paremeters and allow the engine to operate more efficiently. The idea is to restore the power and fuel economy to what it was when it was stock

 

take it to tnt customs. they should help you out. not many 4x4 shops in the 307

 

I run 35's with 4:10 gears. They work great for daily driving but for wheeling, they have a hard time holding the jeep back when going down hill (always tapping the brakes). I'm planning to regear to 5:13's some time when I get the funds to do so... should get me back in the "factory" range

 

Thanks alot. I called them they gave me some ideas and a quote on a great price

 

You called them at 1:00am. Must be one heck of a shop!! All silliness aside you should not only plan for next year but gear according to what tire size you want to goto next. With your lift that you stated you could easily goto a 35 inch tire which is a 34 true size and have a 5.13 gear ratio that make you quite happy!!

 

are you planning on bigger tires? regearing isnt a must, especially with just 33's. I have 5.13s and 35s with an auto and its great. My MPG stayed basically the same going from 3.73s to 5.13s.