Gearing for Gladiator EcoDiesel

[Chief_jeep]

@Mbryson when you say 4000' down the hill, does that mean your in SLC valley? I'm at the top of Parleys summit and commute up near the top of guardsmen and regularly go up LCC. I wouldn't have gone with 4.88s but it's what my shop recommended and have done in the past with success.

If you are going to 39's and regearing you should considering upgrading the axles. I'm sure you know that and it depends how you use your vehicle and drive it. But it's a lot cheaper to pay for it once and do it the way you want it.

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[guarnibl]

My Gladiator is heavy and I am happy with 4.10's and 37" Nitto Recons. Nitro actually did a batch of the 4.30s the boat barely when shopping for the gears. I would have gone that way, but again, I am happy with the 4.10s. The Jeep holds 8th gear on everything except the steeper hills. Fuel milage will range from 21-23 on the highway if I try (based on last trip from WA to Southern CAL). Not bad for a Jeep Motorhome

Here are some RPM ranges for reference from a couple of days ago.

And the size of the Jeep for reference.

Nice Jeep!

I doubt you'd end up with too much of a difference if you switched to a heavier tire combination, so it seems 4.10's are pretty solid then based on what you're saying (especially considering your fuel mileage). Sounds like 4.56 might be too much then and mileage would likely drop slightly.

 

[Mbryson]

@Mbryson when you say 4000' down the hill, does that mean your in SLC valley? I'm at the top of Parleys summit and commute up near the top of guardsmen and regularly go up LCC. I wouldn't have gone with 4.88s but it's what my shop recommended and have done in the past with success.

If you are going to 39's and regearing you should considering upgrading the axles. I'm sure you know that and it depends how you use your vehicle and drive it. But it's a lot cheaper to pay for it once and do it the way you want it.

I am down the hill and just a little north (Bountiful). I'm not sure I'm considering the 39" tires but it is tempting every morning as the Jeep they are on is just sitting. I'm with you on the axle strength. I do know a couple of folks running 39-40" on stock axles but am not sure it's for me and my purposes with this rig. (I would like a little more belly height on the JT, thus the temptation)

 

[River City Offroad]

I have a 22 Ecodiesel JT with about 15K miles on it now. I drove it to Moab last year on 39s with 3.73s and followed my buddy in his identical truck on Toyo MT 40s and 4.88s. We got the same average MPG overall on that trip.

I have since taken his axles with the 4.88s and put them in mine. For a while I was on 40" Razrs and I felt that it was perfect. I initially thought it was slightly over-geared for the 39s with the 4.88s. I have had the 39s back on it for about 5K miles now and its a lot of fun to drive and I no longer feel like I have too much gear unless I'm putting around in a neighborhood.

I personally would not re-gear for 37s with the Ecodiesel and if you do I would go to 4.10 or 4.56 and definitely no deeper.

I was a tester of Nitro's 5.29 gears in the early JL market and they were awesome on the JLUR on 39s at the time. However, they were noisy as hell and I bet we never see the 4.30s come to fruition.

I attached a couple of pics because who doesn't like looking at Gladiators? lol

Holler at me if you need parts or advice! Happy to help in any way that I can!

Marcus

 

[CrazyCooter]

I felt the 37's and 3.73's were fine for my application until I got an RV that was 1' wider and 1.5' taller than my previous RV. My RTT and rack are also are below cab level.

I would have liked a set of 3.92's (not available) with 37's in an all around application where the truck has minimal wind resistance. (no camper or RTT above the cab) and towed say up to 5000lb in the hills.

I went 4.10's and didn't like it with my worn 37's, but had planned to jump up to 38's which split the difference.

We're finding that the guys with the Alu-Cab campers have a bit more wind resistance and need to step up to the next available gear, 4.10's so they can operate into the wind and hold at least 7th at higher speeds.

 

[Steven_B]

I felt the 37's and 3.73's were fine for my application until I got an RV that was 1" wider and 1.5" taller than my previous RV. My RTT and rack are also are below cab level.

I would have liked a set of 3.92's (not available) with 37's in an all around application where the truck has minimal wind resistance. (no camper or RTT above the cab) and towed say up to 5000lb in the hills.

I went 4.10's and didn't like it with my worn 37's, but had planned to jump up to 38's which split the difference.

Were finding that the guys with the Alu-Cab campers have a bit more with resistance and need to step up to the next available gear, 4.10's so they can operate into the wind and hold at least 7th at higher speeds.

Mine (4.10 + 37's + Alu-Cab Canopy Camper) will hold 8th gear in most situations on the highway, only dropping to 7th on more vertical hills. Wind can be a bitch though.

 

[CrazyCooter]

Mine (4.10 + 37's + Alu-Cab Canopy Camper) will hold 8th gear in most situations on the highway, only dropping to 7th on more vertical hills. Wind can be a bitch though.

Yep, drove another stock on 37s yesterday for an extended roadtest and it was windy. 7th unless I was almost coasting.

 

[Dynamic Overland]

My Gladiator is heavy and I am happy with 4.10's and 37" Nitto Recons. Nitro actually did a batch of the 4.30s, but I barely missed the boat when shopping for the gears. I would have gone that way, but again, I am happy with the 4.10s. The Jeep holds 8th gear on everything except the steeper hills. Fuel milage will range from 21-23 on the highway if I try (based on last trip from WA to Southern CAL). Not bad for a Jeep Motorhome

Here are some RPM ranges for reference from a couple of days ago.

And the size of the Jeep for reference.

Great looking jeep! I can’t get anywhere near 20 mpg not sure if it’s my weight or what, I have a med height rack as opposed to yours being over the cab
I know my bed rack is extremely heavy when I’m loaded with my camp gear I really struggle
I find it kind of struggling when non loaded, however I feel I could take some stress of the driveline components gearing a little differently, really I get in and hold 8th just fine, but I’m really impacted on the low end! I heavily debated going with the 4.10, I just felt 4.56 is higher than I want, but there’s a bunch of people running them doing great! I’d feel more comfortable with the 4.10 or 4.30, ideally 4.30 with my weight, I want that Highway gear lol

 

[Troutventure]

To everyone saying they dont think regearing is worth it... If you put on bigger tires you need to regear or you risk damaging your engine. Doesn't matter if it still feels like it has enough power. Here is a guide on what gears to pick based on your engine and tire size https://exodus4x4.com/jeep-regear

 

[CrazyCooter]

To everyone saying they dont think regearing is worth it... If you put on bigger tires you need to regear or you risk damaging your engine. Doesn't matter if it still feels like it has enough power. Here is a guide on what gears to pick based on your engine and tire size https://exodus4x4.com/jeep-regear

Many of us have already been down this road and I live it daily being in the business. That link is just another person's opinion, not fact or law. I happen to disagree with his opinion on the ecodiesel.

Plenty of Eco Rams are delivered with 3.21s and 32" tires for max fuel economy and still have a decent tow rating. That same math works out to 37s and 3.73s if I remember correctly. Its been a while since I actually visited the numbers since I don't need them anymore knowing what works.

Your statement is flawed.

 

[Troutventure]

Many of us have already been down this road and I live it daily being in the business. That link is just another person's opinion, not fact or law. I happen to disagree with his opinion on the ecodiesel.

Plenty of Eco Rams are delivered with 3.21s and 32" tires for max fuel economy and still have a decent tow rating. That same math works out to 37s and 3.73s if I remember correctly. Its been a while since I actually visited th numbers since I don't need them anymore knowing what works.

You statement is flawed.

What if you're on 40s? Not sure how my statement is flawed. Never said it's against the law to run stock gears lol. All im saying is there's a risk and that better mpgs/power aren't the only benefits.

 

[CrazyCooter]

What if you're on 40s? Not sure how my statement is flawed. Never said it's against the law to run stock gears lol. All im saying is there's a risk and that better mpgs/power aren't the only benefits.

This thread was about an eco on 37s?

Yes, of course 40s require deeper gearing. Preferably in a 60/80 combo.

 

[Camaroboi13]

What if you’re on 52s? That’s not what the OP is asking about. He’s in a diesel on 37s. I promise you the diesel doesn’t care if he’s on 37s, he ain’t harming a thing.

OP, I think your rack is just acting like a parachute to be honest. My cruise control gets set to 74mph when I’m not stuck in SoCal traffic, and I drive like an Ahole. That being said, my heavy knobby Ironman mud terrains with steel bumper and winch are still getting me 21.5-22.5 average hand calculated mpg. I can get 23 if I try but it ain’t very fun.

 

[Vtur]

I think it's all about driving styles. If someone are happy with how it perform with stock 33s, than it's recommend to regear when going with bigger tires.

I felt a little lugging right away with the 37s, driving around town. But, it felt fine once it's already picking up speed. I ended up regeared mine a week later.

The lugging can cause stresses to the drive shaft, gears etc. Kinda like stressing the chain and your legs when pedaling a bike in low gears up an incline.

 

[Dynamic Overland]

To everyone saying they dont think regearing is worth it... If you put on bigger tires you need to regear or you risk damaging your engine. Doesn't matter if it still feels like it has enough power. Here is a guide on what gears to pick based on your engine and tire size https://exodus4x4.com/jeep-regear

I did remember calling these guys and seeing this on their site, i agree with the regearing, my only concern was go with the 4.10 wait for the 4.30s or go with 4.56 i still think 4.56 is to high for what im trying to achieve

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