Gear ratio for 37s

[GregMort13]

I have a '13 jku rubicon 10a. Its got the 4.10s in it. Dana 44 front and rear. Had the 3.6L. 6sp. Having a hard time deciding to go with 4.88s or 5.13s. Help!

 

[olram30]

I believe 5:13.

 

[Boji]

I believe 5:13.

X2 on the 5:13's. It's recommended to run 4:88's with 35" tires. I'm sure the 4:88's would be fine but if you want more out of your rig go for the 5:13

 

[WhiteDynamite]

I have a '13 2-door 6-speed on 37's and went with 4:88.... Go 5:13's

 

[2013rubirick]

I have a 2013 JKUR on 37's and I have 5.13's and its perfect. I wouldnt do anything else

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[wetfootnw]

I'm scheduled next week to have 5.13 gears installed. Good write up on Project-JK here that helped me decide.

 

[CrazyLarry]

I run 488s on a 2012 6 speed and feel it's got plenty of power for my 37s I couldn't imagine 513s but you guys are saying its perfect would love to give your rigs a try and see what I'm missing. Than again maybe I don't so I don't feel guilty for getting 488s lol

 

[JKAnimal]

I am running the 5.13s and couldn't be happier. :yup:

 

[Jerms]

513s

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[BigBoy]

Most with real world experience seem to say 5.13.

Here is a chart that may help. By this it looks like 4.88 would be closer to factory.

 

[turbineguy]

I have 4.88 with 6-speed, 3.6, and 37" MTRs and it has no issues, even on hills. Having said that, I'd go 5.13 if I had to do it again, but 1st gear would be useless in most cases.

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[H8MUD]

Most with real world experience seem to say 5.13.

Here is a chart that may help. By this it looks like 4.88 would be closer to factory.
View attachment 79652

EDIT: Never mind...found it.

 

[mudsled]

I had 488 and 513 on my 08 and the difference is only 2 to 300 rpm difference. I did like the 513"s better tho..:thumb:

 

[Pjmjk]

Have 5.13s with a 3.8L with 37 " toyos love it

 

[Jeep_Dawg08]

Well.. I am pulling the trigger next week.
Replacing the 3.73 with 4.88 in my d30/d44.
I am anxious to see how things turn out.
I have basically 33 Nitto TG and decided to go 4.88 since I don't see going over 35s.
I now am searching for the best/affordable programmer since that is a necessity now. Any suggestions???

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[pastorwug]

Well.. I am pulling the trigger next week.
Replacing the 3.73 with 4.88 in my d30/d44.
I am anxious to see how things turn out.
I have basically 33 Nitto TG and decided to go 4.88 since I don't see going over 35s.
I now am searching for the best/affordable programmer since that is a necessity now. Any suggestions???

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ORE typically suggests the AEV Procal. A basic programmer that does the job simply and well.

I bought the Superchips and love it, works well and has additional settings the AEV Procal doesn't have.
The Superchips Flashpaq model also has performance settings but at a premium expense above the Superchips Flashcal model.
You can purchase the Flashcal model and then update it to the Flashpaq model through a software change later on if you want the performance settings.

 

[Grubbicon]

I got a 3.8 auto stock 4.10s that i ran of 37s. I wouldnt change it. It was fine. And setting the cruise on 70 going down the interstate i would get 16 mpg.

 

[ZuidJK]

Well.. I am pulling the trigger next week.
Replacing the 3.73 with 4.88 in my d30/d44.
I am anxious to see how things turn out.
I have basically 33 Nitto TG and decided to go 4.88 since I don't see going over 35s.
I now am searching for the best/affordable programmer since that is a necessity now. Any suggestions???

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I have only used the AEV Procal and it works awesome..super easy to use and really affordable just flip the rocker switches with key in and engine off then listen for the horn.

 

[JayKay]

I'm so up in the air on regearing now:sigh: I have a '12 JKUS with 3.73s and 35s. Can't decide to go 4.88 or 5.13. It'll be a while before I swap out the D30 for a PR44, if it ever happens. So I'm not really sure about going with 5.13s in the D30. My Jeep is 90% highway driven and will probably be that way the whole time I own it. I do plan on moving up to 37s eventually. Would I be good running 4.88s since my Jeep is mostly on the highway?

 

[DA RUNT]

I'm so up in the air on regearing now:sigh: I have a '12 JKUS with 3.73s and 35s. Can't decide to go 4.88 or 5.13. It'll be a while before I swap out the D30 for a PR44, if it ever happens. So I'm not really sure about going with 5.13s in the D30. My Jeep is 90% highway driven and will probably be that way the whole time I own it. I do plan on moving up to 37s eventually. Would I be good running 4.88s since my Jeep is mostly on the highway?

I wouldn't go lower than 4.88's on a 30. The charts look like that will bring you very close to stock. I've seen folks run 4.88's and say they love them.