Hello, I know this has been posted before, I am sure thousands of times, but I need a more specific answer so please bear with me. I currently have a 2008 2-door JK with an auto transmission. The only modifications I have done to it are the 35" tires and the 2.5" budget boost. Now I am pretty sure that I have the 3.21 gears being that it is a stock X model. Now my question is that I will be going to college soon and I feel that regearing is an essential upgrade being that I will be doing a lot of high way driving, knowing this what would be the best gearing to get for my jeep so that highway driving will be more enjoyable and my mpg will be at its best, I know its a Jeep . I also would like to do some off roading as well, I do not know if any of this plays a part in choosing a specific gear ratio. Overall what gearing will be the best for my needs, so far from what I have gathered 4.88 will be my best bet, but I would like to here if this is true or not because I am new to this and I do not want to mess this up.

While I am at it, my steering wheel is very loose. Is there a way to tighten the steering with either an after market part or by tightening a simple screw?

Thank you for your help guys!
Matt

 

We would go to 5:13's. It will be much better for the 35's and tolerable with 37's should you decide to go that big. The expensive part of gearing a vehicle is the labor so you mind as well do it once.

 

Going with 37's in the future is a possibility, with the 5:13's and 37's will it be comparable to my current setup of 35's with 3:21's or far superior. Also will the 5:13's be better than 4:88's with highway driving and off roading?

Thanks for your reply

 

37's and 5.13's will make it feel almost like stock.

The 5.13's will be an overall better choice than 4.88's.

 

I would only add that 5.13's with 35's might limit your top end speed on the highway,,, unless you enjoy turning high rpm.

 

Why? At 75-80 I'm at ~2600 with 5.13 and 35's.

To the op-

I personally feel that my pinion is the weak spot on my front end due to the size when you go with 5.13, and it's the one thing I can't fix on the trail other than a bent housing. I'm happy with the on road performance and gas mileage. Knowing the pinion is my weak point I take it easy on the skinny pedal Offroad.

Also not sure where you are in Michigan but there is a guy in Fenton who does gears for cheap and does a good job. He did my gears, locker, sleeves, gussets, control arm skids, and ball joints for $700 labor. Just the gears would have been ~ $400. Pm me if you are near there and want his number when you are ready to re-gear. Jeeperz creeperz is also affordable and a great place but he is usually scheduling a few weeks out so keep that in mind.

 

After almost endless research, I went with 4.56 and I'm very happy with that decision. I'm not saying that it's a better ratio, just be sure you do your homework before spending the money. A 5.13 ratio would be unbearable for me, specially on the highway - YMMV

 

I wish I could give you a perfect answer but gearing is a very tough decision, very subjective and becomes a balance of your priorities. With the Rubicon or an aftermarket transfer case it becomes a lot less critical off road not to mention an auto and/or the 3.6 L also helps if you have the auto set to proper shift points.

I went with 4.88 but I have a manual with the 3.6. It is great for me but some people might not like it for long trips at say 80 mph. I do a lot of off road and I was burning up the clutch with 3.73, some people feel 3.73 is fine for them and regearing isn't worth the cost. I have a friend with a 12 Rubi on 37's with 4.10. He has no interest in regearing and feels his CAI was plenty for his needs and the lower 4L gear does it on the rocks.

When I got my gears done the mechanic took it out to test it. He couldn't believe how well it performed compared to other rigs with 5.13 but the 3.8L. He always felt the older JK on 35's was a dog on the road with 5.13's. Then again I would never go higher with a d30. I would be too worried about snapping teeth.

For mileage I think 4.56 to 4.88 would do well for you. I personally would hate 3.21 with 33" or bigger with the 3.8 or the 3.6. If you are going to spend the money and are considering 37's I would go 5.13 but that's me. You are usually looking at between $1000-1500, some places as much as $2000 but that is robbery, it's not something you want to do often. I had the benefit of talking to a great local shop owner who gave me great advice and in the end I'm very happy. We'll see how I feel when I go 37's but I'll be running a pr44 front before that happens and will need to open the rear for a locker anyway so I might just bump up for them.

 

the 3.8 will handle 35's just fine with 5.13's. its not much higher RPM than the 4.88's

 

I have been researching gears for the past couple of months. I have decided to go with 5:13's. I need to purchase soon cause my current 3:73 rear is starting to have some vibration issues. And also I currently have 35's with a three inch lift. Any good idea's were to purchase.