Gear ratio for 37s

GregMort13

Caught the Bug

• Apr 16, 2014

• #1

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

Not That Kind of Engineer

• Apr 16, 2014

• #2

I believe 5:13.

 

Boji

New member

• Apr 17, 2014

• #3

olram30 said:

I believe 5:13.

Click to expand...

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

New member

• Apr 17, 2014

• #4

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

 

2013rubirick

Hooked

• Apr 17, 2014

• #5

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

Sent from my SAMSUNG-SGH-I537 using WAYALIFE mobile app

 

wetfootnw

Member

• Apr 17, 2014

• #6

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

 

C

CrazyLarry

New member

• Apr 18, 2014

• #7

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

Caught the Bug

• Apr 18, 2014

• #8

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

 

Jerms

New member

• Apr 20, 2014

• #9

513s

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BigBoy

New member

• Apr 20, 2014

• #10

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

New member

• Apr 20, 2014

• #11

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

New member

• Apr 20, 2014

• #12

BigBoy said:

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

Click to expand...

EDIT: Never mind...found it.

 

M

mudsled

New member

• Jul 23, 2014

• #13

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:

 

P

Pjmjk

New member

• Aug 15, 2014

• #14

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

 

Jeep_Dawg08

New member

• Aug 15, 2014

• #15

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

New member

• Aug 15, 2014

• #16

Jeep_Dawg08 said:

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???

●|||||||●

Click to expand...

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

New member

• Aug 15, 2014

• #17

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

New member

• Aug 15, 2014

• #18

Jeep_Dawg08 said:

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???

●|||||||●

Click to expand...

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

Caught the Bug

• Aug 16, 2014

• #19

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

New member

• Aug 16, 2014

• #20

JeepKeeper said:

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?

Click to expand...

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.