Feedback/experience on 4.10s with 37s

[CheatyJeepy14]

So I am looking for this information because I am trying to decide on buying & building up a Sport/Sport S or buying a Rubicon:

I know there are people out there out driving a Rubicon with 4.10s, 8-speed auto, 37 inch tires. I am looking for their opinion on how they enjoy the ride quality and performance/efficiency of the vehicle. I would imagine a programmer would definitely be a must to allow the vehicle to adjust shift points for the larger tires. In any event, I’m trying to determine if the 4.10s are enough based on people’s feedback. Of course, Re-gearing to 4.88s would be better but it doesn’t mean that 4.10 performance is bad.

To put it in perspective, I currently have a JK Sport with 3.73s on 35s. A bit sluggish but overall I love the way my Jeep handles and drives. I just tell you this cause it shows you what I consider decent performance (even if you think I am nuts!). Thanks for any feedback!

Edit: I appreciate your feedback if you are going to tell me about your opinion on Re-gearing. However, if you haven’t driven the gladiator yet with the set up I mentioned, then I don’t believe you can really give me a trustworthy opinion on it. Please only give me feed back if you have driven a rubi with 4.10s, auto trans, 37s.

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[wyldefreebyrd]

On 35s and no issues, keeps up with traffic no problem. Have pulled a boat and had to manually select gears to find the best one to ride in, found that 6th was best overall. If left alone transmission keep switching between 4th-5th. Gas mileage isn't as good as 33's or smaller tires but is better than the old JKU on 35's.

 

[beelzebot]

So I am looking for this information because I am trying to decide on buying & building up a Sport/Sport S or buying a Rubicon:

I know there are people out there out driving a Rubicon with 4.10s, 8-speed auto, 37 inch tires. I am looking for their opinion on how they enjoy the ride quality and performance/efficiency of the vehicle. I would imagine a programmer would definitely be a must to allow the vehicle to adjust shift points for the larger tires. In any event, I’m trying to determine if the 4.10s are enough based on people’s feedback. Of course, Re-gearing to 4.88s would be better but it doesn’t mean that 4.10 performance is bad.

To put it in perspective, I currently have a JK Sport with 3.73s on 35s. A bit sluggish but overall I love the way my Jeep handles and drives. I just tell you this cause it shows you what I consider decent performance (even if you think I am nuts!). Thanks for any feedback!

Edit: I appreciate your feedback if you are going to tell me about your opinion on Re-gearing. However, if you haven’t driven the gladiator yet with the set up I mentioned, then I don’t believe you can really give me a trustworthy opinion on it. Please only give me feed back if you have driven a rubi with 4.10s, auto trans, 37s.

I ran the 35" KO2s on factory Moab wheels on my JK with 3.73. It was a dog. Slow acceleration and on hills it couldn't decide what gear it wanted to be in. It wasn't bad enough for me to pony up for the regear because I was already in Scrambler or nothing mode (when we thought that would be the name of the JT). On my JT Rubicon (4.10 gear ratio) I run the 37x13.5R17 Nitto Ridge Grapplers on this wheel: https://www.quadratec.com/p/mopar/satin-black-5-spoke-wheel

I couldn't be happier with the setup. My gas mileage is shit (around 14 city) but the ride is smooth and soft and it looks fantastic too. Haven't noticed any shifting issues even on hills. I think the 8-speed transmission really makes a big difference. Yes, you'll want a programmer or to have a dealer do it, but most dealers charge for that so you might as well get a Tazer Mini and enjoy the future flexibility and extra features.

 

[beelzebot]

Don't forget that you can get the 4.10 ratio and wider axles with a Sport S and max tow package though. If you don't want to pay for the other Rubicon stuff because you'll just replace it anyway, that might be a good option. I wanted lockers from the factory and the 8.4" Nav so it was Rubicon for me.

 

[Chevis 50]

https://www.jeepgladiatorforum.com/forum/threads/feedback-experience-on-4-10s-with-37s.20391/

Just linking here so I can get plenty of opinions on this matter. Thank you!

I'm running 37" BF KM3s on my LE with my speedometer adjusted for tire size and it actually shifts better then my stock Power wagon did. It does down shift on hills quite a bit but you barely notice. But even my Power wagon did that with 5.7 Hemi and it was a lot more noticeable. MPG is around 16 to 17 city and highway.
All said very happy with the way it performs.

 

[Renegade]

After a week of driving my Rubicon on 37's, I'll echo what several have said- The 8-speed automatic transmission has negated the "need" to regear for 37s. My JT with 4.10s pulls 37s much better than my JK did with 4.88 gears. Gas mileage does suck, with mine showing around 15 mpg, but it's actually about 10% better than indicated (haven't corrected the speedometer for the tires yet), and I live on a mountain.

 

[TheSolarWizard]

I think wheel and tire choice will be the determining factory on whether you need to regear or not. One of my employees paid attention to me so he traded the dealer his stock wheel and tires for a takeoff set of the overland 18s and he chose the cooper at3 xlt (59lbs Which is 9lbs heavier than the stock Falken ATs or 3lbs lighter than the stock MTs) in 285/75/18 which is about 34.5 with the rubicon on the ground. There’s virtually no discernible difference in performance vs stock and he’s getting about 19.6 hand calculated mpg in mixed driving. Compared to the average 37 on the average aftermarket wheel, he’s around 25lbs per corner less and that’s huge

E: I think the tire looks fantastic also and I’ve been in the Jeep. The tread is whisper quiet and handles incredibly well in torrential rain. I think it comes with a 60k warranty as well. Strongly recommended if you don’t really need an MT

 

[TennesseePA]

It’s been said so I am just an echo. I picked my LE up with 12 miles on it with the 37s already mounted. It pulls the cruise control at 75. It has no deficiencies in acceleration or braking. I love the way it rides and drives and if a bus runs over this one I’d build another one exactly like it. Anyone who says that a JT with .410 and 37s is a dog hasn’t driven a JT with .410 and 37s.

 

[canyonrat]

Looking at gearing closely also and comparing to my current JKUR with 4.10’s. With 315/70r17 KO2’s, it struggles to stay in 5th gear at highway speeds (75mph) which is .83 ratio.

7th gear on JT is .84 ratio so almost same. Same engine basically. So those of you with 37’s on JT with 410’s it may drive ok, but do you ever actually see 8th gear get used? Maybe down hills? So it becomes more like a 6 or 7 speed auto, not bad I suppose.

Makes me wonder if paying for Max Tow for 4.10ks is such a good idea or better to just go Sport S without Max Tow and immediately put the money saved towards a regear to 4.88’s if one wants 35’s or 37’s. Maybe I’m wrong and comparing apples to oranges?

 

[TennesseePA]

The whole purpose of having a second overdrive (8th gear) is so that the engine turns as slowly as possible under the lightest load possible. As the load increases a transmissions job is to downshift and lessen the load. The 3.6 is a very high revving engine, especially when under load. Mine will shift into 8th gear while on a flat surface, going downhill and it will pull 8th gear on some very moderate slope. That is exactly what it is supposed to do. There are two ways to get a load to the top of the hill. The one everyone seems to think the Gladiator should do is to have massive low end grunt which places a very heavy load on the engine. Or you can let the engine spin at higher RPM with much less of a load on it. Either way you get to the top of the hill. We did not buy slow turning torque monster trucks so why should one expect it to perform like one? Let the transmission do its job and let the engine scream all it wants to to get the work done.

 

[KDR83]

I test drove a gladiator Rubicon with 37s and a Mopar lift today and it was a complete dog. Maybe I'm just used to sports cars or maybe because the wheels were 22s with 37 inch grapplers on them? Sure it drove fine in traffic but man you could tell it was pushing some heavy tires.

 

[TennesseePA]

I guess I’ll never understand what people expect from a pickup truck these days. My LE with 37 KO2s on factory rims will easily break the rear tires loose if I give too much skinny pedal pulling into traffic. If it has enough power to break traction with big tires on warm dry pavement then it has enough power for me.

 

[TheSolarWizard]

I test drove a gladiator Rubicon with 37s and a Mopar lift today and it was a complete dog. Maybe I'm just used to sports cars or maybe because the wheels were 22s with 37 inch grapplers on them? Sure it drove fine in traffic but man you could tell it was pushing some heavy tires.

They added around 45 lbs per corner with that combo not surprised it was a dog and it should be put down

For reference that’s similar to the effect of adding 1800+ lbs into the bed.

 

[TennesseePA]

They added around 45 lbs per corner with that combo not surprised it was a dog and it should be put down

For reference that’s similar to the effect of adding 1800+ lbs into the bed.

are you sure about that 45 lbs per corner? Just to make sure I looked up the weight of my 37x12.5r17 BFG KO2s and they tip the scales at 69 pounds each. I also looked up the mass of the Fallen WildPeak ATs that my LE came with and they are 63 pounds per tire. That is a grand total of 24 pounds added to the unsprung weight of my Gladiator. I would say that the differences in rolling mass are negligible if even perceptible. The gear change of the larger diameter tire lowers my .410 to about a .373. I have said it before and I will say it again I could not ask for my Gladiator to be any more fun to drive.

 

[KDR83]

are you sure about that 45 lbs per corner? Just to make sure I looked up the weight of my 37x12.5r17 BFG KO2s and they tip the scales at 69 pounds each. I also looked up the mass of the Fallen WildPeak ATs that my LE came with and they are 63 pounds per tire. That is a grand total of 24 pounds added to the unsprung weight of my Gladiator. I would say that the differences in rolling mass are negligible if even perceptible. The gear change of the larger diameter tire lowers my .410 to about a .373. I have said it before and I will say it again I could not ask for my Gladiator to be any more fun to drive.

I think he was talking about my specific example, The grapplers are close to 80lbs each in that size and 22 inch fuel wheels were over 50 lbs each.

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