I want to change my rear end to 5.13 gears. Do i have to change my front to or can i leave the front stock?

 

Front and rear's need to be replaced with 5.13 gears.

 

You dont HAVE to change the front, but if you dont then you need to pull the front driveshaft out. If you put it in 4wd with 2 different ratios in the axle get ready for a surprise and some exercise.

 

Yes, both have to be the same.

Here is some reading for you to make you a pro..

https://www.jk-forum.com/forums/show...?82262-Gearing

 

Thanx guys! Rather do it right the first time. Also, will the 5.13 gears give me better torque?

 

what size tires do you have? I had 5.13s with 35s (heavy nitto mud grappler on huge 18x9 ultra wheels) and I think I could smoke a stock JK off the line. It gives you the extra power that the JK should have came with IMO. If you have 37s or larger expect stock performance with them since 5.13 with 37s is very close to 4.10s with 32s like a stock rubi.

 

I have 32 mud-terrain. My jeep has the 3.73 gears and it sucks! Maybe if they put a 5 speed auto tranny in, it would do better with the 3.73. And it dosnt do better on gas milage. In fact i think it does worse. I live in Oregon so we really dont have that many straight aways and really dont have any highways. Going up any kind of hill with 4 people in the jeep u can really hear the engine working harder than it should.

 

Start by buying yourself a Superchip Flashpaq. That will solve your problems in the meantime. Or at least make your JK a lot more enjoyable to drive....at least it did for me.

 

I second the Flashpaq. I just got mine yesterday and only have about 20 miles on it so far, but it made a pretty big difference. I have 35's with the stock 4.10 gears. I will still need to re-gear in the future, but this will help me live with it in the meantime.

 

5.13'S is a bit much for the stock tires, even on an auto. If you truly plan on staying with the stick tires look at the 4.10-4.56 gear range. Superchips and Hypertech both make great tuners that might meet your needs at a much lower price point as well.