I know I know….. Need real world feedback. 5.13-35’s

[WITCH3R]

I know this has been beaten to death. However I am looking for rear world feedback with someone running 35’s with 5.13 gears. I live in Texas do some hwy driving but most in town. I may upgrade to 37’s and may not. I plan on adding armor and doing some light towing. Cost is going to be $2,600 so I want to do it right the first time. I have the Willy’s sport and get about 12-15 mpg with stock gearing. (What ever that is).

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[Panthers65]

I was between 4.88's and 5.13's with 37's, 35's on the hwy and you're going to be screaming. It'll do it, and you'll love driving around town, but I wouldn't imagine you'll be happy at anything above 65mph.

I've run a truck with 488's and 33's before, off road toy but I did put it on the highway a few times, it got up and shifted fast, just have to know its limitations. I wouldn't do it with a DD

 

[HooliganActual]

On my JKUR, I run 4.56's with 35's and I think its just about right. It came from the factory with 3.73's but if it had had the 4.10's I probably would have left it that way.

Now, my JTR has the factory 4.10's and I'm running 37's with a fully loaded overlanding setup. I scaled it at about 100#'s over GVWR with all gear, food, water, etc. and I have no problems on the highway and with hills. I see 8th gear occasionally on flat sections, lol.

All that said, I personally think that 5.13's are too tall for 35's and maybe even for 37's.

Not that this info is definitive, this site recommends:https://4xstore.com/news-tech/what-...-jeep-wrangler-jk-jku-jl-jlu-or-gladiator-jt/

And while this is the chart for the Wrangler, I suspect it's not far off from what the JT would need:

Back to your request, I don't have experience on 35's with 5.13's but I think those gears would be too tall.

 

[BlueScapegoat]

This is the best gear calculator out there imo. Plug in your current setup and the regear, or stock vs regear, etc, and take a look. I like to match the rpm to stock plus just a bit to help with wind and rolling resistance, rotating inertia, etc.


Grimm Jeeper Gear Calc


I don't have experience regearing a pentastar first hand but without plugging in numbers 5.13 seems too steep. That's what I run in my TJ with 37s and a 6 speed.

 

[Wheelin98TJ]

I was between 4.88's and 5.13's with 37's, 35's on the hwy and you're going to be screaming. It'll do it, and you'll love driving around town, but I wouldn't imagine you'll be happy at anything above 65mph.

I've run a truck with 488's and 33's before, off road toy but I did put it on the highway a few times, it got up and shifted fast, just have to know its limitations. I wouldn't do it with a DD

It would be about 2,500 RPM at 70 in 8th gear.

I don’t think that’s bad at all.

 

[jeep1]

The charts are interesting but don't match my experiences....

I am running 37x12.5 Nitto Trail Grappers and Hutchinson beadlocks... admittedly a heavy combo. With 4.56s I never saw 8th gear unless I was going downhill. Highway climbs were awful. Stuck in 3rd or 4th with the engine screaming. Regeared to 5.13 and it's just SO much better. Regularly see 8th gear on the highway. I can actually keep up to traffic on highway climbs now, passing is safer and it's just so much more of a joy to drive.

If I lived somewhere flat, 4.56s would have probably been fine but the PNW is nothing but hills !

With 35s and a lighter wheel.... I'm sure 4.56 would have been fine

 

[glassjawkid32]

Not to thread jack but I'm also planning on 5.13 soon. What happens if the truck was to be driven but my tazer has been un married(like a warranty service scenario)?

 

[AustinL911]

On my JKUR, I run 4.56's with 35's and I think its just about right. It came from the factory with 3.73's but if it had had the 4.10's I probably would have left it that way.

Now, my JTR has the factory 4.10's and I'm running 37's with a fully loaded overlanding setup. I scaled it at about 100#'s over GVWR with all gear, food, water, etc. and I have no problems on the highway and with hills. I see 8th gear occasionally on flat sections, lol.

All that said, I personally think that 5.13's are too tall for 35's and maybe even for 37's.

Not that this info is definitive, this site recommends:https://4xstore.com/news-tech/what-...-jeep-wrangler-jk-jku-jl-jlu-or-gladiator-jt/

And while this is the chart for the Wrangler, I suspect it's not far off from what the JT would need:

Back to your request, I don't have experience on 35's with 5.13's but I think those gears would be too tall.

Those charts are wrong. The AT in 8th gear is taller (numerically lower) than the MT is in 6th. So the AT should have a lower RPM than the MT in their respective top gears, assuming full converter lock up. They are not on these charts. Perhaps they're just mislabeled. Regardless, go with @BlueScapegoat suggestion and punch it I to the calculator.

To the OP: AT or MT?

If you have aspirations of hitting 85+ mph frequently and sticking with 35s, I'd run 4.88. If 37, then probably 5.13. I also wouldn't be scared to run 5.13 if I never planned on going over 80mph (or at least not very often) and also still wanted 35s. That's exactly what I'm doing in my MT JTR.

Here's some math for you. My tires (STT Pro) measure 34.6". In 6th gear with 5.13, I can run 83mph before I engage the 2nd stage oil pump (3000rpm). That's my personal arbitrary threshold. With an AT, you could probably run 85 or so before that happens. I don't know who would possibly want to run that fast in one of these things with 35 or 37" tires, but I'm not one of those people. Also keep in mind that these engines love to rev. At 60mph, mine gets better fuel mileage in 4th gear at 27xx than it does in 5th at 23xx. Unless you have a data logger, it's hard to see what load cell the engine is operating within at a particular speed/rpm. Anecdotally, mine gets better mileage at higher rpm, to a point. Higher rpm does not necessarily mean worse mpg.

 

[TreyK42]

Not to thread jack but I'm also planning on 5.13 soon. What happens if the truck was to be driven but my tazer has been un married(like a warranty service scenario)?

Tire size and gear ratio adjustments made via the Tazer are not "live" functions and do not require the Tazer to remain connected to your vehicle.

If you go in for a warranty or recall that requires a software update it will (more than likely) erase the settings previously set by your Tazer and you'll need to update them after leaving the dealership.

I run 37's and 5:13's and recently had a recall done for a software update. I removed my Tazer, drove to the dealership and had the update done, and reconnected the Tazer in the dealer parking lot to reprogram my tire size and gear ratio before driving home.

 

[dcmdon]

my back of the napkin math gives you about 2540 rpm at 70 mph on 35s

And about 2465 on 37s. at 70 mph.

 

[dcmdon]

Tire size and gear ratio adjustments made via the Tazer are not "live" functions and do not require the Tazer to remain married to your vehicle.

If you go in for a warranty or recall that requires a software update it will (more than likely) erase the settings previously set by your Tazer and you'll need to update them after leaving the dealership.

I run 37's and 5:13's and recently had a recall done for a software update. I unmarried and removed my Tazer, drove to the dealership and had the update done, and re-married the Tazer in the dealer parking lot to reprogram by tire size and gear ratio before driving home.

you are wrong because you are confusing married with in place.

It's not a live function, so you can remove the Tazer after the change. But if you unmarry it, the adjustment will go away.

 

[TreyK42]

you are wrong because you are confusing married with in place.

It's not a live function, so you can remove the Tazer after the change. But if you unmarry it, the adjustment will go away.

Correct...I used the wrong verbiage. I'll edit the post.

 

[dcmdon]

Correct...I used the wrong verbiage. I'll edit the post.

I just experienced it today. I'm going in later today for my last Jeep Wave oil change and removed and unmarried this morning. It's really amazing how all the live functions make the Jeep just easier to live with. In a quick trip this morning, the following things were a new annoyance.

1) seat belt chime
2) garage door opener/homelink doesn't stay active after I shut off the ignition
3) License plate light blanking.

 

[glassjawkid32]

Tire size and gear ratio adjustments made via the Tazer are not "live" functions and do not require the Tazer to remain connected to your vehicle.

If you go in for a warranty or recall that requires a software update it will (more than likely) erase the settings previously set by your Tazer and you'll need to update them after leaving the dealership.

I run 37's and 5:13's and recently had a recall done for a software update. I removed my Tazer, drove to the dealership and had the update done, and reconnected the Tazer in the dealer parking lot to reprogram my tire size and gear ratio before driving home.

So no damage to the diff from the computer thinking you were on stock gears? Reason I ask is I could swear I saw a post claiming their diffs blew in that exact scenario. Did you unmarry or simply remove?

 

[glassjawkid32]

you are wrong because you are confusing married with in place.

It's not a live function, so you can remove the Tazer after the change. But if you unmarry it, the adjustment will go away.

See that's my concern because if you don't unmarry you risk losing whatever flash they did correct? And if you unmarry you risk damage? Anyone know what the deepest gear set a dealership can flash is?

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