5.13s or 5.38s with what tire size and why?

[bleda2002]

I ran 37s on 410 and now 39s. I'm regearing to 5.13s Thursday. That said, driving around Florida 37s are ok on 4.10s if you are just doing on road stuff. 39s is pretty miserable but I could still see someone who only stays on the road and never really tows or hauls being fine with it.

Last week we went to the Smoky mountain jeep invasion, and 39s on 4.10s was absolute misery to the point where it was almost a safety hazard. I had to use first all over the place and a lot of throttle on some steep roads and trails it was no fun.

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[SuperUltraMan]

I ran 37s on 410 and now 39s. I'm regearing to 5.13s Thursday. That said, driving around Florida 37s are on 4.10s if you are just doing on road stuff. 39s is pretty miserable but I could still see someone who only stays on the road and never really tows or hauls being fine with it.

Last week we went to the Smoky mountain jeep invasion, and 39s on 4.10s was absolute misery to the point where it was almost a safety hazard. I had to use first all over the place and a lot of throttle on some steep roads and trails it was no fun.

Yeah I can feel your pain. Rolling on 38s wasn’t ideal with the stock 4.10s but going to 40s made my transmission go full retard, even with flashing for tire size and speedometer.
Getting gears soon.

 

[bleda2002]

I’m sure that your avatar says it all about you.


Yeah I can feel your pain. Rolling on 38s wasn’t ideal with the stock 4.10s but going to 40s made my transmission go full retard, even with flashing for tire size and speedometer.
Getting gears soon.

The worst one was a fairly steep longish climb off road, that really shouldn't have been a big deal. I didn't really realize how steep it got so I tried to do it in 4h and literally had to be in first and floored and i was still worried about stalling it on the way up as it just couldn't get going past 5 or 6 mph on the way up it.

After that the wife understood why I had scheduled gears when the 39s went on lol.

 

[WILDHOBO]

The worst one was a fairly steep longish climb off road, that really shouldn't have been a big deal. I didn't really realize how steep it got so I tried to do it in 4h and literally had to be in first and floored and i was still worried about stalling it on the way up as it just couldn't get going past 5 or 6 mph on the way up it.

After that the wife understood why I had scheduled gears when the 39s went on lol.

4H should almost never be used off road. It’s so hard on the tranny, and very difficult to manage throttle control. I can imagine that was a tough climb.

 

[WK2JT]

I’ll throw My $.02 in the ring

5.13’s w/ 37’s is the the minimum gearing I would consider.

Now if you live at elevation like Denver, want to tow, or do a lot of off-roading, I’d go 5.38’s.

I have 2 out of 3 of these considerations and wish I would have gone 5.38. However, 5.13’s do just fine.

Either way, your hwy speed is going to be RPM limited, but I don’t care to drive it at 80 MPH anyway. Before that, I consider it aero limited. After 65, the drag on this brick is so bad your mileage tanks. I don’t want try an emergency maneuver at 80 either… not that 65 is any better for that.

This has been my experience and I plan to regear to 5.38 when I do axles. Now someone will say something about pinion head strength.

 

[JT1]

37's with 5.13s on a 3.6 6spd. Highway cruising is stress free now, put it in 6th and from 55 to 80 it just maintains speed. Around town its a little shifty, and I find myself skipping gears occasionally. Honestly with the minimal difference between 4.88 and 5.13s, cruising mph is probably the biggest consideration. If you drive on the 75/80mph turnpikes, 4.88s will likely make you happier.

Best change I've done to the jeep since I bought it.. drives like it should've from the factory. All the manuals should come with 4.56s.

 

[Wheelin98TJ]

I ran 37s on 410 and now 39s. I'm regearing to 5.13s Thursday. That said, driving around Florida 37s are ok on 4.10s if you are just doing on road stuff. 39s is pretty miserable but I could still see someone who only stays on the road and never really tows or hauls being fine with it.

Last week we went to the Smoky mountain jeep invasion, and 39s on 4.10s was absolute misery to the point where it was almost a safety hazard. I had to use first all over the place and a lot of throttle on some steep roads and trails it was no fun.

The need for deeper gears on road is maybe even more than the need for off road. You don’t use 4 low like you can when off road.

4H should almost never be used off road. It’s so hard on the tranny, and very difficult to manage throttle control. I can imagine that was a tough climb.

Sand is one place you don’t use 4 low much, if at all.

 

[Bonanza]

That’s a guy that hasn’t had any experience with gears. All the “4.10s are fine” folks don’t have any experience.

To me 35s aren’t worth it. There’s no value in those tires anymore. But with 35s there’s no value in regearing too.

4.10s are fine. Regarding experience, I did my regear myself, with my own hands.

That said, 4.88s are a big meh for me. 5.13s probably the sweet spot.

 

[Orange01z28]

5.13s
37” Yokohama x-at
3.6
Auto
I went back and forth between 4.88s and 5.13s. My installer suggested the 5.13s. I went from 3.73s to the 5.13s and really like it.

Same

I'm almost did 4.88s but i'm glad I went 5.13, especially for off-road

 

[BLK HOLE]

4.10s are fine. Regarding experience, I did my regear myself, with my own hands.

That said, 4.88s are a big meh for me. 5.13s probably the sweet spot.

“4.10s are fine”

followed by

“Needs more than 20% more gear to perform correctly”

luls.

 

[Bonanza]

“4.10s are fine”

followed by

“Needs more than 20% more gear to perform correctly”

luls.

It is fine. 5.13 is where I suspect a difference would be noticeable. For those debating whether to plop down thousands, the results are not as big as, for instance, my old JK with 3.21s with a 6 speed.

 

[BLK HOLE]

It is fine. 5.13 is where I suspect a difference would be noticeable. For those debating whether to plop down thousands, the results are not as big as, for instance, my old JK with 3.21s with a 6 speed.

Its not fine. Driveline load is harder, offroading gearing suffers even more, as does driveline load that much more coming up rocks. Plus...your gas mileage suffers. Yes, 4.88s are a waste of time too.

 

[Bonanza]

Its not fine. Driveline load is harder, offroading gearing suffers even more, as does driveline load that much more coming up rocks. Plus...your gas mileage suffers. Yes, 4.88s are a waste of time too.

It's fine.

The jump from 4.10 to 4.88 has not resulted in even a tenth of an MPG increase, anecdotally. I document my results in my gear install thread. The 8 speed transmission in these are incredibly good at compensating. In a pure vacuum of "which would I choose from the factory", I'd pick 4.88 for a 37 for most needs, 5.13 for heavily loaded. But for those debating whether a regear is going to blow your minds, it simply doesn't. I would not have the same opinion in an older JK.

I did all of the below on a 4.10, with absolute ease:

 

[BLK HOLE]

It's fine.

The jump from 4.10 to 4.88 has not resulted in even a tenth of an MPG increase, anecdotally. I document my results in my gear install thread. The 8 speed transmission in these are incredibly good at compensating. In a pure vacuum of "which would I choose from the factory", I'd pick 4.88 for a 37 for most needs, 5.13 for heavily loaded. But for those debating whether a regear is going to blow your minds, it simply doesn't. I would not have the same opinion in an older JK.

I did all of the below on a 4.10, with absolute ease:

Yeah I can see that you used them like that. That went without saying.

But you’re wrong. It’s not a matter of can you do it, it’s a matter of should you. And you shouldn’t. You do you tho - not my Jeep. I just care enough to make sure other people don’t follow that advice.

 

[JT1]

It's fine.

The jump from 4.10 to 4.88 has not resulted in even a tenth of an MPG increase, anecdotally. I document my results in my gear install thread. The 8 speed transmission in these are incredibly good at compensating. In a pure vacuum of "which would I choose from the factory", I'd pick 4.88 for a 37 for most needs, 5.13 for heavily loaded. But for those debating whether a regear is going to blow your minds, it simply doesn't. I would not have the same opinion in an older JK.

I did all of the below on a 4.10, with absolute ease:

Love it! Anecdotally, I never really felt massively undergeared in the rocks in 4LO.. 3.73s/5.13 first gear/2.72 on 37s. 4HI was nearly useless however. Now, with 5.13s, my crawl ratio is still only at 71.6, but things that would stall the jeep before unless I slipped the clutch don't bother it.

The biggest change was on road.

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