37's and Gears

[Jasonr82]

Hello Everyone,
I had a question regarding lifting my Gladiator and replacing the gears. I am not doing much aggressive off roading therefore I've decided on going with the cost friendly 3.5" Rough Country Suspension Lift. My plan is to run 37" Tires with 20x12" Rhino Rims. With that set up, do I have to change up the gear ratio or am I okay with running my stock gears. I also plan on purchasing the speedometer calibration kit from Rough Country as well but none the less I've gotten mixed reviews with the gearing situation.
Thanks.

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[Desert Outlaw]

Your ride with load range 'E' tires for those 20" wheels will be rough. Plus, you will be limited with how much you can air down for the times that you do go off road. You're much better to stick with 17" wheels and load range 'D' or 'C' if not loading the truck down much.

You didn't mention if you have a manual or automatic?

 

[Lynn_F]

What gears do u have? I installed the Skyjacker 3.5" lift on my Sport S Max Tow and the 4.10's handle my 37's just fine.

 

[MaximusJTRubi]

What gears do u have? I installed the Skyjacker 3.5" lift on my Sport S Max Tow and the 4.10's handle my 37's just fine.

Sorry to thread jack, but can you please get a measurement from the ground to the top back of the hard top, and one from the ground to the front door sill? Please?

 

[spazzyfry123]

Which JT do you with which axles? Here’s a good thread for the Max Tow and Rubicon crowd with 37s (4.10 gears)

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

 

[Lynn_F]

Sorry to thread jack, but can you please get a measurement from the ground to the top back of the hard top, and one from the ground to the front door sill? Please?

Top of hardtop? =79" / Door sill = 28.75"

 

[Jasonr82]

Looking at my window sticker it shows I have the 3.73 Gears. Would that be enough or do I have to upgrade?

 

[Lynn_F]

I had 3.73's on my JKU with the same wheel/tire setup that I have now and it worked fine. It was a little sluggish but got better gas mileage. I was still able to pull my SxS with it and overall it was fine. That being said, I can definitely tell the difference with the 4.10's and 8 speed tranny. My opinion is to get the wheels and tires that you want...it is definitely doable with 3.73's and then you can upgrade later.

 

[WhatExit?]

3.73's and 37's is a recipe for replacing your gears. You'll want to plan on it and you'll see how it goes with the gears before you ante up the coin for them

 

[nuut]

I am running 37" ProComp Tires on 17" rims with the 3.73 gears and an auto trans. I've taken it on some pretty gnarly trails without any issues. On the highway I'm usually in 6th gear @ 70mph. Fuel economy is ~16mpg. I plan to change my gears some day but it's definitely not neccessary to do right away

 

[TRAILJT]

Hello Everyone,
I had a question regarding lifting my Gladiator and replacing the gears. I am not doing much aggressive off roading therefore I've decided on going with the cost friendly 3.5" Rough Country Suspension Lift. My plan is to run 37" Tires with 20x12" Rhino Rims. With that set up, do I have to change up the gear ratio or am I okay with running my stock gears. I also plan on purchasing the speedometer calibration kit from Rough Country as well but none the less I've gotten mixed reviews with the gearing situation.
Thanks.

The gears are not 100% necessary but your transmission will thank you for it later. I had stock 4.10s on my rubicon and am running 37x12.50x17s. My transmission was constantly shifting back and forth between 6th,7th and 8th. I went with 4.88:1 and I love it for just everyday use. I have not had it off-road since the re-gear but I am sure it will be just that much better. It’s pricy but well worth it in my opinion. I am sure there are a bunch of other opinions out there. I would say if you have the money do it.

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