Just Went to 33s / Do I Go to 4.30 or 4.56 ?

[Zachanadandy]

Zach, that's where I have to disagree. The difference between 1 mph and needing 0.5 mph is HUGE.

I put my stock JTR on 35's through some crap and I need the brake pedal more than the accelerator on trails. 4.88's would be amazing, but I drive it all over the country and like the deep overdrive on the highway.

I am a big no re-gearing fan, unless you need bottom end; then you need to re-gear. At highway speeds the transmission with it's 8 speeds will find the right one.

It's an auto though, so even those rolling back scenarios are easily controlled with the left foot even while maintaining throttle. In a manual I'm a huge fan of super deep gearing, in an 8 speed auto with a very deep 1st gear I just don't see the advantage. I tend to drive faster than most on trails unless it's a technical section of rocks so again I found 5.38s to be a downgrade all around. The Jeep was actually slower 0-60 by a half second as the trans had to shift 1 extra time. The only place I felt any advantage was reversing in high range as our reverse gear is significantly taller than 1st. The 4.56s felt overgeared on the freeway with the stock 35s. A stock JL sport or sahara can wheel/crawl just fine with its 3.45s and 32s even with its 2.72-1 tcase. That ratio is equivalent to 4.56s and 42s in high range or 62" tires with the 4-1 tcase and 4.56s in LO. Those sport guys on the same trails must be professional drivers to make their rigs work without all that "necessary" gearing?

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[Heavy D]

I need the ability to rip donuts in 2 Hi...
Maybe I should have started off with that.

 

[Zachanadandy]

That’s obviously on the extreme end of the conversation, well past daily drivers that wheel. But I’ve seen apples to apples comparisons, repeatedly, of lower low ranges compared to stock rubicons with 4:10, to 3.73 8 speeds, to 3.73 manuals. It’s a compelling difference with climbing up something, needing to stop without roll back with a tire perched, turn, and continue at a controlled speed. The same goes for steep controlled descents. It does make a noticeable difference. I would regear, or buy any other part to “say that I have it”. I upgrade for function only.

And your comparisons are on the extreme end too. That JL or JT with 3.73s doesn't have the 4-1 low range. They'd need 6-1 axle gears just to match the stock 4.10x4-1 Rubicon. That alone tells me a Rubicon almost never needs more crawl ratio, or those other guys are just fat better drivers as even geared all the way down to 5.38s they run the same obstacles with much less gearing. I am anti-regear in a modern 8 speed Rubicon from experience. I put out all the relevant information. I do drive fast. On road I prefer the way a non-rubicon is geared stock having driven tens of thousands of miles in both. Tens of thousands of miles on 37s and 4.10s, 4.56s and 35s, 4.56s and 39s, and 5.38s and 38s all behind the 8 speed auto I definitely prefer the taller side. 4.56s would be perfect for 37s and 4.88s would be prefer for 39s for my use but those moves are far too small to justify regearing either our JLUR or my JTM. The JTM holds 8th for hours at a time every time we drive to our AZ property on 37s and stock gears at 85mph and 2000-2100 rpm. If it ain't broke don't fix it.

 

[Zachanadandy]

I need the ability to rip donuts in 2 Hi...
Maybe I should have started off with that.

In the dirt or on pavement? The cost of the regear is about half the cost of a supercharger, wanna wager which one rips better donuts by a long shot?

 

[Wheelin98TJ]

It's an auto though, so even those rolling back scenarios are easily controlled with the left foot even while maintaining throttle. In a manual I'm a huge fan of super deep gearing, in an 8 speed auto with a very deep 1st gear I just don't see the advantage. I tend to drive faster than most on trails unless it's a technical section of rocks so again I found 5.38s to be a downgrade all around. The Jeep was actually slower 0-60 by a half second as the trans had to shift 1 extra time. The only place I felt any advantage was reversing in high range as our reverse gear is significantly taller than 1st. The 4.56s felt overgeared on the freeway with the stock 35s. A stock JL sport or sahara can wheel/crawl just fine with its 3.45s and 32s even with its 2.72-1 tcase. That ratio is equivalent to 4.56s and 42s in high range or 62" tires with the 4-1 tcase and 4.56s in LO. Those sport guys on the same trails must be professional drivers to make their rigs work without all that "necessary" gearing?

You should tell people you're talking about a turbo JL when you say it's slower 0-60 with deeper gears. It's misleading on this forum without that tidbit since we don't have turbo Gladiators.

 

[Heavy D]

In the dirt or on pavement? The cost of the regear is about half the cost of a supercharger, wanna wager which one rips better donuts by a long shot?

Wherever my song comes on...

Already been looking at superchargers. Once someone can 'sell me on one' that won't beat the bottom out my 3.6... I'll be the guy that always has bald tires on the back.

 

[Zachanadandy]

You should tell people you're talking about a turbo JL when you say it's slower 0-60 with deeper gears. It's misleading on this forum without that tidbit since we don't have turbo Gladiators.

Slower is slower, and if you gear deep enough that you add an extra shift the 3.6l will be slower as well. The 3.6L revs higher, but there's at least 1 guy on here that went 5.13s with 33s and he would definitely be into an extra shift making the 0-60 go down.

 

[dmwphoto]

No, just making a joke at pedal commander's expense.

I'm actually thinking of making a GladiatorForum bingo card. "Pedal Commander is a necessity", "phone mounts", "regearing", "start/stop is eeeeeevil" and "will my 33" tires fit on my stock truck?" could win on a daily basis.

This!!

 

[Wheelin98TJ]

Slower is slower, and if you gear deep enough that you add an extra shift the 3.6l will be slower as well. The 3.6L revs higher, but there's at least 1 guy on here that went 5.13s with 33s and he would definitely be into an extra shift making the 0-60 go down.

I'm not going to be able to convince you.

If we ever have the chance to bet $100 on a Gladiator drag race, I'm in.

 

[Zachanadandy]

I'm not going to be able to convince you.

If we ever have the chance to bet $100 on a Gladiator drag race, I'm in.

I'm pretty sure the ecodiesel has a turbo and would be even worse by being geared too low as it has a pretty low red line. Gear that thing like y'all recommend and you might be 2 extra shifts into a 0-60, but I understand your argument. As far as the drag race, make it 0-100mph in the dirt and I'll take that race any day of the week. Let me know if you ever make it out to the desert.

 

[AmishMike]

@Zachanadandy because I do all the stupid things on a trail with a stock JTR and 35's, I have to run them SLOW so that when I drag skids I am not slamming things.

@Heavy D I believe that the 3.6 was designed for turbos, so the bottom end is fine. Getting the tune right was the problem, but I lost track a year or two ago. Ah, and heat build up.
What you need is Line-lock! Then you can blow donuts wherever you want, and for safety it can keep you from rolling backwards on those treacherous speedbumps.

 

[WILDHOBO]

It's an auto though, so even those rolling back scenarios are easily controlled with the left foot even while maintaining throttle. In a manual I'm a huge fan of super deep gearing, in an 8 speed auto with a very deep 1st gear I just don't see the advantage. I tend to drive faster than most on trails unless it's a technical section of rocks so again I found 5.38s to be a downgrade all around. The Jeep was actually slower 0-60 by a half second as the trans had to shift 1 extra time. The only place I felt any advantage was reversing in high range as our reverse gear is significantly taller than 1st. The 4.56s felt overgeared on the freeway with the stock 35s. A stock JL sport or sahara can wheel/crawl just fine with its 3.45s and 32s even with its 2.72-1 tcase. That ratio is equivalent to 4.56s and 42s in high range or 62" tires with the 4-1 tcase and 4.56s in LO. Those sport guys on the same trails must be professional drivers to make their rigs work without all that "necessary" gearing?

Anyone can do these trails without regearing. No one is arguing that. But for rock crawling, steel ascents, and steep descents, its worlds better. I for one go slowly on trails. I bypass almost nothing, and will attempt everything. It the most dangerous stuff, but I wouldn’t do half the things I do with 4.10s, let alone 3.73s. I just have more control.

 

[dmwphoto]

a fun read here https://www.jeepgladiatorforum.com/forum/threads/2020-overland-rear-diff-issues.61131/page-4

 

[Zachanadandy]

Anyone can do these trails without regearing. No one is arguing that. But for rock crawling, steel ascents, and steep descents, its worlds better. I for one go slowly on trails. I bypass almost nothing, and will attempt everything. It the most dangerous stuff, but I wouldn’t do half the things I do with 4.10s, let alone 3.73s. I just have more control.

I was using extreme examples of stock Jeep configurations, including the JK we used to wheel. I'm not arguing that a 45-1 crawl ratio is optimal at all. But there comes a point where it really doesn't feel all that different in an auto. 85-1 in the stock xr is more than enough for even the steepest climbs or descents even on 39s. I'm not arguing that 3.73s and 40s are a good combo, but I'd rather run that than 4 56s and 33s as regardless of how often I get out and wheel the time driving on the road to get to and from those wheeling trips would be miserable. I've gone to the deep end of gearing more than once and every time it has sucked, although the double overdrive does make it suck less. I love the fact that I can comfortably roadtrip the Jeep at 85mph+ and then run 8+ rated trails when I get there. That is what is so impressive about the modern JL/JT platform. Pretty much every prior Jeep was a compromise where you're gearing limited your top speed to 70mph or you flat didn't have the torque to crawl up steep obstacles at elevation. Thanks to the low 1st gear and double overdrive you can do both with ease. I prefer to shoot for 2k rpms at 75mph. Some prefer 2500 so that the motor is more into its power band. I don't want to be in the power band when cruising around at light loads. Jeep themselves are all over the board with gearing so there could never be a consensus. From my experience and the way I drive I'll post in every thread debating the topic that there is such a thing as gearing too deep and there are drawbacks. In my opinion the benefits are far over stated as well. Having extensively crawled with the stock Rubicon 77-1 and the added 5.38s and 101-1 in the exact same Jeep i can honestly there's little gain. 77 is slow enough to creep up or down anything. Short of 40"+ I'll never go below 4.88s with this trans. Lesson learned the hard and expensive way. With the current xr, going from the 85-1 to 91-1 by dealing to 4.88s would likely not even be noticeable.

 

[ShadowsPapa]

This is not true. Heavy D has this exact setup and his motor isn’t screaming down the road. And he has stated that his mileage has actually improved.

I know a few above have stated that 8th isn’t really supposed to be used etc.. However, by re-gearing with lower gears, it will make 8th a lot more usable. With 3.73, my truck stays in 7th a lot on the highway and rarely falls into 8th. However, by doing a 4.56 it will now use 8th and be running close to the RPM that it was running with the 3.73 in 7th.

No one will be able to explain the whole concept to you in forum posts, you are missing multiple points and taking things to either extreme.
No one is saying "8th is to be used sparingly" or rarely or anything like that.
There's just big reasons - engineering reasons, for how things shake out as they do with tire sizes, gearing, transmissions, etc.
There's the whole concept of heat rejection and other factors that it's just not worth even trying to get into as it would take pages.

Do what you want to do - but it's not based on science, it's based on preference, opinion and personal preference

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