5.13 vs 5.38

JK1

JK1

New member
I know Eddie posted this on the JK facts and questions
Q: What gear ratio should I be running with 37" Tires?
A: In order to bring your Jeep's performance back to stock, you will need to run 5.13 gears with 37" tires.

But when i look at the chart it says 5.38 are in the green for 37.... that being said my friends are also split on what gears to run:crazyeyes:.

info..2010 JKRU auto, I live in iowa (rolling hills and now with 35 and 4.10 gears it down shifts on every little hill or god fore bid there is any wind) i will be going to colorado to wheel 1-2 times a year pry wheeling 5 other times around here, i drive mine 40+miles for work everyday, I am installing 37 13.5 17 toyo on slabs this weekend (i may never go bigger than 37 but not gonna promise that :brows:lol) ...

I'm just trying to nail down my next purchase.:D

Thanks for the help in advance
Matt
 
5.38 is a good ratio to run with 37's but, it'll also be one that leaves you with a tiny tiny pinion which will be a weak point. Granted, when I did it, I was running 40's but, it didn't last long at all. I wouldn't go with anything bigger than a 5.13 in a Dana 44.
 
wayoflife said:
5.38 is a good ratio to run with 37's but, it'll also be one that leaves you with a tiny tiny pinion which will be a weak point. Granted, when I did it, I was running 40's but, it didn't last long at all. I wouldn't go with anything bigger than a 5.13 in a Dana 44.
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that makes sense i didnt think of the pinion size:thinking: but will the 5.13 give me the same down shifting issue and having to run with the O/D off most of the time or will it be low enough to fix most these issues...
or do i just need to do a engine swap to a 6.2 to fix all of this ;)
 
JK1 said:
that makes sense i didnt think of the pinion size:thinking: but will the 5.13 give me the same down shifting issue and having to run with the O/D off most of the time or will it be low enough to fix most these issues...
or do i just need to do a engine swap to a 6.2 to fix all of this ;)
Click to expand...

So long as you properly calibrate your speedometer, your shift points should be on and the 5.13's will work just fine.
 
You will like the 513s


I don't always wheel , but when I do I keep it tight......... Stay dirty my friends.
 
I had 4.10 in my Jeep and once I moved to 37s it was really sluggish. I have a manual so shift points weren't an issue but the RPMs were too low for my liking. Towing was a real PITA! Once I moved to 5.13 I honestly feel like the Jeep drives better on the highway than it did with the 4.10/32" combo. I am very satisfied with the 5.13s. It's great in 4 low also. :thumb:
 
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I love the 5.13's in mine, but I'm also running 35's for now. And as mentioned above the 5.13's in low make a huge difference.

2011 JKU 3.5 R.E. Longarm lift.
 
5.13s in my Rubicon, with 6 Speed and 37's ..... Love the combo, Wouldnt have it any other way

:drinks:
 
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