5.13 Gears, My Thoughts and Real Numbers

[JarHeadLV]

That's assuming it will naturally find 8th gear. Will most likely spend more time in 6th and 7th.

Right now with the 37's (37x13.5r17) I do not get into 8th gear on freeway. I don't do alot of freeway driving though either, but I do realize no matter what re gear size I choose, I need to re gear.

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[Wheelin98TJ]

That's assuming it will naturally find 8th gear. Will most likely spend more time in 6th and 7th.

It will definitely spend a lot of time in 6th and 7th with 38s and 4.88.

That's why I'd go with 5.38 for 38s.

 

[JTenn]

Right now with the 37's (37x13.5r17) I do not get into 8th gear on freeway. I don't do alot of freeway driving though either, but I do realize no matter what re gear size I choose, I need to re gear.

As mentioned before any deeper gear will help that condition if you keep the same diameter tire. But if you step down in gear ratio and up in tire size you're basically netting the same result. 5.13's eliminate that issue.

 

[Wheelin98TJ]

Im going to guess the 38"s are actually close to 36" (if that matters) based on my 37's are exactly 35" when mounted on my truck, same with a buddys truck with 37's.

I wonder when I DO move up to new gears, what can I sell my current 4.10s for? they have 3,100 miles on them currently

Roughly 3% difference between 37 and 36. Adds about 50 RPM at 70 MPH.

You might be able to get $100 for the used pair of ring and pinions, but they won't be an easy sell. Maybe a JL guy looking to go from 3.45 to 4.10.

 

[JarHeadLV]

Roughly 3% difference between 37 and 36. Adds about 50 RPM at 70 MPH.

You might be able to get $100 for the used pair of ring and pinions, but they won't be an easy sell. Maybe a JL guy looking to go from 3.45 to 4.10.

thats disapointing!!! What brand do you guys recommend for new gears?

 

[Wheelin98TJ]

thats disapointing!!! What brand do you guys recommend for new gears?

Dana Spicer for Dana axles.

 

[JarHeadLV]

Dana Spicer for Dana axles.

ok thanks.....makes sense!

 

[JTenn]

thats disapointing!!! What brand do you guys recommend for new gears?

100% Dana Spicer

 

[MrClortho]

thats disapointing!!! What brand do you guys recommend for new gears?

I got talked out of Yukon which is what I used on my JK...apparently either there are some flaws cropping up or their support has been an issue for my Jeep shop and they are more costly. We went with Revolution Gear instead, and he had installed dozens of sets of them with great feedback. So far they have been flawless and silent.

 

[Wheelin98TJ]

I got talked out of Yukon which is what I used on my JK...apparently either there are some flaws cropping up or their support has been an issue for my Jeep shop and they are more costly. We went with Revolution Gear instead, and he had installed dozens of sets of them with great feedback. So far they have been flawless and silent.

Revolution are good too.

Last I knew, Revolution ring and pinions are made by Circle K.

 

[ttn333]

Had 5.13 installed about a month ago. I've also put in a couple thousand miles since with two multi days trips. For daily driving, I don't think it's that big a deal, at least for me. Im not a speed racer with this beast. There's not really any appreciable gain in mpg either, maybe 1 mpg if I'm paying attention. I can get 14mpg if Im real careful. Otherwise it's around 13 mpg. Shifting has been good from the get go, for the most part. Im in 8th a lot, on the highway. It's definitely peppier. Where the gearing really shines for me is going up the mountain passes. I'm not lugging it up in 2nd or 3rd like before. As a matter of fact, I'm not thinking about it as much. I haven't towed yet. But I bet its going to feel so much better. I run a constant load too (alucab canopy, tent, awnings, fridge and some gear, on 37s).

 

[JTenn]

Had 5.13 installed about a month ago. I've also put in a couple thousand miles since with two multi days trips. For daily driving, I don't think it's that big a deal, at least for me. Im not a speed racer with this beast. There's not really any appreciable gain in mpg either, maybe 1 mpg if I'm paying attention. I can get 14mpg if Im real careful. Otherwise it's around 13 mpg. Shifting has been good from the get go, for the most part. Im in 8th a lot, on the highway. It's definitely peppier. Where the gearing really shines for me is going up the mountain passes. I'm not lugging it up in 2nd or 3rd like before. As a matter of fact, I'm not thinking about it as much. I haven't towed yet. But I bet its going to feel so much better. I run a constant load too (alucab canopy, tent, awnings, fridge and some gear, on 37s).

I'm super happy with the 5.13's and have no regrets whatsoever. My actual milage is around 17 to 18 though. Could just be the terrain, road conditions or environmental differences. I'm still on 35's but some day I'll move up to 37's.

 

[Zachanadandy]

If you're on the fence about steep gears and you live out west where speed limits start with an 8 and everyone drives 5-10mph over, don't do it. Our 2019 JLUR was better on 4.10s and 37s on road than it was on 5.38s and 38s. Lost about 2mpg in daily driving and about 1 mpg on the freeway. It was in 8th gear at any speed over 45mph with nowhere to go from there but higher into the rpms. Long downhill stretches of the freeway where you'd see 8th gear and 2200rpm with 4.10s became 3200rpms. It's a double overdrive transmission, the idea that you want it in 8th gear all the time is lost on me. Our 2022 JLUR with the XR package came with 4.56s and 35s, and it still felt too low to me at freeway speed. Now on 39s I have no desire to regear it whatsoever. It's perfect. 7th most of the time on the freeway, and 8th under low load conditions the way a double overdrive is supposed to work. Mathematically it falls about half way between a stock sport with 3.45s and 32s and a Rubicon with 4.10s and 33s. My mojave is still stock, and the 4.10s and 33s are good but I'd have no problem bumping up to 35s or even 37s without a regear. If you tend to drive fast, the deep gear ratios aren't great in my experience.

 

[Jeeperjamie]

Yeah seeing some of these latest figures makes me glad I have not regeared on 37's with my 4.10 gears on my Max Tow. I average 17 to 17.2 and get 18 to 18.5 on long trips, even trips to the Smokey Mountains. Even when I towed about 4500lbs of rock it still felt like it had plenty of power and I got 13.5 to 14 for the 50 mile trip back. See 7rh and 8th pretty regular, 8th more than 7th on the interstate and I'm in the Foothill/Piedmont section of NC, 2 hrs from Black mountain.

 

[ttn333]

I have no regret with the 5.13 gearing. I am happy with it. It's what I wanted and I've done my research before going in. I didn't expect to gain power or mpg. It does great going 80 mph on the highway. I have too much crap on my truck to go much faster than that. Just know what and why you're regearing before paying for it.

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