There is no debate, go 4.88 gears (my review)

[JTPatriot]

Going to update my experience with the 4.88's and 37 Patagonia milestar's. Living in Kansas and not towing it does fine. Mostly holding 8th gear 70-80 mph dropping into 7th occasionally, which is fine.
Went to Colorado this last week pulling a 3500 lb. Rpod camper. 60-65 mph. Spent most of the time in 5th at around 3500 rpm's occasionally going into 6th and sometimes dropping into 4th up hills or if the headwinds picked up. Fuel mileage went from everyday use of 13-14 mpg's to 8-9 mpg's pulling.
On the way back my son had his 3/4 dodge ram cummins an instead of constantly filling up the JT he hooked on to it and away we went! My mileage went from the 9 mpg's pulling to 19.5 mpg's not towing. That was great, plus that was at 70 mph.
So I am still not sure if 5.13's would have been good as for the everyday use and even for towing because if it still could not hold 6th or 5th and would drop into 4th, man would that engine be screaming.
Really think it just comes down to the torque of the motor just does not quit having enough to hold those transmission gears where they need to be.

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[WK2JT]

Going to update my experience with the 4.88's and 37 Patagonia milestar's. Living in Kansas and not towing it does fine. Mostly holding 8th gear 70-80 mph dropping into 7th occasionally, which is fine.
Went to Colorado this last week pulling a 3500 lb. Rpod camper. 60-65 mph. Spent most of the time in 5th at around 3500 rpm's occasionally going into 6th and sometimes dropping into 4th up hills or if the headwinds picked up. Fuel mileage went from everyday use of 13-14 mpg's to 8-9 mpg's pulling.
On the way back my son had his 3/4 dodge ram cummins an instead of constantly filling up the JT he hooked on to it and away we went! My mileage went from the 9 mpg's pulling to 19.5 mpg's not towing. That was great, plus that was at 70 mph.
So I am still not sure if 5.13's would have been good as for the everyday use and even for towing because if it still could not hold 6th or 5th and would drop into 4th, man would that engine be screaming.
Really think it just comes down to the torque of the motor just does not quit having enough to hold those transmission gears where they need to be.

Thanks for sharing... this is very helpful. So I guess the question is, if you were to do it over again, would you stick with 4.88 or go to 5.13? I know you said you're not sure, but curious if you would lean more one way than the other. The scenario you described in CO is exactly what I'm going to be experiencing in a few months, so I really appreciate this.

 

[Phljeeper]

This thread was a great read, I second the question, if you were to do this over again would you stick with 4.88s? I am about 80% confident I am going 4.88 but have a slight doubt in my mind that maybe I should go 5.13.

 

[JTPatriot]

Thanks for sharing... this is very helpful. So I guess the question is, if you were to do it over again, would you stick with 4.88 or go to 5.13? I know you said you're not sure, but curious if you would lean more one way than the other. The scenario you described in CO is exactly what I'm going to be experiencing in a few months, so I really appreciate this.

You know, I think I would probably go with the 5.13's knowing how it does now towing and when not towing. It will add about 114 rpm's over the 4.88's which i am not even sure you would notice in economy. My only concern would be if it does drop into 4th at 60-65 mph it will be screaming. But may be worth it in the long run.
Can't do it now, not going to fork out that much money on gears and install this soon.
4.88/8th gear@ 75 mph = 2227 rpm's
5.13/8th gear @ 75mph =2341 rpm's

6th gear is 1:1
4.88 @ 65 mph = 2881 rpm's
5.13 @ 65 mph = 3028 rpm's

 

[JTPatriot]

I do not want to hijack the op's thread either so I hope he does not mind my thoughts within this thread. I can always start a new one if he wants me to.

 

[Texops]

I have 4.88's and 35's pulling a camper in WV. If I had 37's and were pulling a camper in the Rockies. I'd go 5.13's. Just my 2cents.

that's the reason i went with 5.13's with 37's and towing my 4500# camper it is the best for my needs no regrets.

 

[WK2JT]

You know, I think I would probably go with the 5.13's knowing how it does now towing and when not towing. It will add about 114 rpm's over the 4.88's which i am not even sure you would notice in economy. My only concern would be if it does drop into 4th at 60-65 mph it will be screaming. But may be worth it in the long run.
Can't do it now, not going to fork out that much money on gears and install this soon.
4.88/8th gear@ 75 mph = 2227 rpm's
5.13/8th gear @ 75mph =2341 rpm's

6th gear is 1:1
4.88 @ 65 mph = 2881 rpm's
5.13 @ 65 mph = 3028 rpm's

That’s what these forums are all about... share information and experience. I for one really appreciate you sharing. I’ve seen a lot about driving characteristics after changing gears, but not a lot on towing and high elevation. If I was going to stay in GA, I’d probably go with 4.88, but considering I’ll be in Denver before long, I think 5.13 would be a better fit due to the power loss. Again, I really appreciate you sharing.

 

[2Jeeps&PatriotX1]

As someone who lives in Denver and tows a 3400lb offroad camper on a regular basis, I've been heavily contemplating going to the Ecodiesel for its torque. Currently have a '17 GC Trailhawk w/ 3.6 and 8speed and it's awful towing the camper through the rockies and mountain passes. Now granted the gear ratio is 3.45 but I'm skeptical as to even if I went w/ the 3.6 and gearing to 4.88s or 5.13s running 37s, will I still hate it. I understand it's not even remotely close to my 3.5 eco boost f150 towing and power wise, which hauls a** up the mountain passes (6k-12k' elevation) with that camper in tow but even w/ 4.88s in my LJ, the only way I could enjoy driving on the highway (don't tow the camper w/ it) even to work was by adding a turbo which brought it back to life.

So my question is for you guys towing at higher elevations, will I regret getting a 3.6, running 37s and gearing it to 4.88 or 5.13s and it still underperform towing? Maybe I'm spoiled with my truck that runs 2200-2300rpm towing up the passes at 70mph and not having it scream at 4500rpm and feeling like Flintstones trying to foot pedal up the mountain.

 

[wvyankee2]

As someone who lives in Denver and tows a 3400lb offroad camper on a regular basis, I've been heavily contemplating going to the Ecodiesel for its torque.

If I were you the Diesel would be for sure.

 

[Phljeeper]

As someone who lives in Denver and tows a 3400lb offroad camper on a regular basis, I've been heavily contemplating going to the Ecodiesel for its torque. Currently have a '17 GC Trailhawk w/ 3.6 and 8speed and it's awful towing the camper through the rockies and mountain passes. Now granted the gear ratio is 3.45 but I'm skeptical as to even if I went w/ the 3.6 and gearing to 4.88s or 5.13s running 37s, will I still hate it. I understand it's not even remotely close to my 3.5 eco boost f150 towing and power wise, which hauls a** up the mountain passes (6k-12k' elevation) with that camper in tow but even w/ 4.88s in my LJ, the only way I could enjoy driving on the highway (don't tow the camper w/ it) even to work was by adding a turbo which brought it back to life.

So my question is for you guys towing at higher elevations, will I regret getting a 3.6, running 37s and gearing it to 4.88 or 5.13s and it still underperform towing? Maybe I'm spoiled with my truck that runs 2200-2300rpm towing up the passes at 70mph and not having it scream at 4500rpm and feeling like Flintstones trying to foot pedal up the mountain.

If I were buying now rather than a year ago I would go diesel. While it is more expensive and has some minor risk being new to the Gladiator it will be better for your situation. I also tow often and my TT is 4700 lb. The Gladiator does well and I am upgrading to 4.88s with 37s to improve. However IMO the diesel would be better in mountains. Relatively flat ground does fine (even on 37s and 4.10s).

 

[2Jeeps&PatriotX1]

If I were you the Diesel would be for sure.

If I were buying now rather than a year ago I would go diesel. While it is more expensive and has some minor risk being new to the Gladiator it will be better for your situation. I also tow often and my TT is 4700 lb. The Gladiator does well and I am upgrading to 4.88s with 37s to improve. However IMO the diesel would be better in mountains. Relatively flat ground does fine (even on 37s and 4.10s).

Thank you for the honest opinion. We had the Ecodiesel in our '15 GC prior to this GC 3.6 and we loved the power. This was before we bought the camper.

 

[Texops]

The 3.6 doesn’t mind screaming all day long most of the power band is high in the rpm range. Even a Jeep Engineer said that it needs to be reved Often.
ill share this
This post was on Bob Is The Oil Guy. Thought you all would like to read it.

Nice! As an former Pentastar design engineer I am slightly bias but the engine is really high quality. Few points from the development using tens of millions of dollars in analysis and testing regarding the oil and durability..... The lighter oil was chosen mostly for fuel economy BUT engineering is the science of compromise. You help one thing but hurt another. A thicker oil will reduce timing chain and tensioner wear because the center timing chain idler doesn't go fully hydrodynamic till about 1650rpm on 5w-20. So, a thicker oil will lower that number slightly and with general loads/speeds the engine spends a lot of time around 1500-1750 rpm with the 8 speed. So thicker oil is a win there. Additionally, the earlier engines had what was called the "McDonald's Arches" in the idler bearing which was intended in making a more uniform distribution but in actuality acted as a knife edge. This design was changed around 2014 to a smooth bearing. So overall timing chain issues will likely follow the 2011-2014 engine years more than 2014+. Where you lose.... The head is very complicated with a Type II valve train. Meaning lots of things to pressurize and pump up at start up. A thicker oil didn't do so well here (on long sit times +cold start) and contributed to a overall increased engine wear especially in the head and cam bearings. Last point. This engine needs occasional WOT runs if you want it to last. Granny cycling is bad for it. So bad for it we actually created a new granny cycle test during the cylinder #3 misfire issue. The highest wear is in the valve guides, because of tight valve stem seals (for emissions, reduce oil burn). They basically dry out. When you go WOT/high rpm/load you get some fresh oil in there and this keeps the wear down. Thicker oil might not help this condition but we also change the valves/guides/seals in 2014+. Not sure the impact. Cheers! Kevin PS. Turn off stop start and do not run e85 if you are concerned about engine wear. Eats the engine alive.

 

[jurfie]

Lots of good discussion here in the "Gears for 37" tires" thread. This post takes you to a chart I made for the JL/JT (similar to the one @PyrPatriot posted for the JK). Consensus is the grimmjeeper calculator is king for determining your exact needs, but the chart is a good starting point for most people.

 

[Brfertig [HACKED ACCOUNT]]

I concur my friend, I made a video and completely agree. There is no debate 4.88 gears are the way to go.

Really happy with how this turned out. Hope you enoy my newest video with some bonus footage of Guams seascapes of the Pacific.

 

[Silvertruck]

Its been a while since i checked in on this thread. So glad it seemed to help some folks.

After about 90 days and about 3k miles on the jeep since install, its still one of the best mods I’ve done. Really happy with it. Still turning around 17mpg mixed driving too.

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