What is the best gear ratio for 37" tires (2020 Gladiator Overland)

[Scott L]

I posted the 8speed gear ratio as well.

The charts are super helpful thanks. I'm actually in a similar situation as OP.

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[Doubled41]

Check out Independent 4x in the Hanover Air Park. They did a lot of work to my last Jeep, and I had a great experience with them.

 

[Panthers65]

I'm running 37's and 5.13's and it's great, but honestly if I were you my decision would be between 5.13's and 5.38's.

Your driving a brick, a refrigerator on wheels. Nothing you do will help you with gas mileage above 75 mph, accept that now. When in doubt, I always recommend overgearing. The different in 5.13's and 5.38's is tiny, like <5%.

 

[Pedal Metal]

I hadn't seen these chart posted, but recalled it as helpful for me to conceptualize gearing. Source:
https://prodigyperformance.com/blogs/blog/jeep-wrangler-gear-ratio-calculator

Enjoy

 

[Iddpaul]

I have a small Gradywhite that I’ll be pulling with the truck. My concern is that I can’t stay in 7th or 8th gear for my transmission when driving normally. Wasn’t sure if this would hurt or shorten the life in my transmission.

Hi just joined the forum as I purchased a JT Ecodiesel a couple of weeks ago and I'm in process with 37's, a Clayton lift and Dana 4:56 gears (going to be towing).

I've been active on other Jeep forums and had many different Jeeps over the years, most with gear changes and lifts (dependent upon my use). For the past three years I've been running a gasser (JLUR/3.6/auto), 3.5" lift, 37's and 4:88's and it's perfect for where I live (20' above sea level and a road trip to any destination). If I were at higher elevations, in the hills, doing more climbing or regular towing I would have gone 5:13's with the 3.6 motor and auto, without a second thought.

Whatever you do, it's super important to re-set the computer with the correct gear/tire ratio so that your shifts are correct. From experience it's really dependent upon your setup, the environment and intended use. IMO a gasser with factory 4:10's, I would go for 35" tires either 4:56 (probably closest to factory settings) or 4:88"s if towing. For 37" tires, either 4:88's or 5:13 (I towed with 4:88's but not in the hills, and just bought the JT for better towing capacity). If you setup your ride correctly, and don't go crazy off-road then I've found wear was about normal. Do remember with 37's you will be adding some more weight, torsional stress to the drivetrain and steering components, so longterm expect additional component change outs at some point. (knuckles, heavier steering, driveshafts, balljoints, etc., etc.).

So in short, if it were me, towing and in the hills I'd go 5:13 (I see no reason to go numerically higher - lower gears than 5:13), if I was doing more road trips (highway) with lighter towing or overlanding then 4:88 is a great all-rounder. Best to you!

 

[YetiJeep]

I just purchased a 2020 Gladiator with 37" tires but the gear ratio doesn't seem right. The jeep struggles to stay in 8th gear (automatic transmission). I've read a lot that I should be at either 4:88 or 5:13 but not sure what is preferred. I'm not overly familiar with gear ratios' etc. but was wondering if there is any sort of suggestion on a place I can take it in the Mechanicsville, VA area that someone would recommend.

I would like to say that 4.88 is good to get back to stock but wish I had went to 5.13 due to weight that I have added to the Gladiator. I have a large tent, water supply, and a Decked system. I also tow with it 18’ enclosed trailer, car hauler and a dump trailer. Hopefully this helps you out with your decision.

 

[Wild thang]

4.88 for the win

 

[dwick37]

Live in Utah a 4500’ and have 37’s with 4.88 and and don’t see 8th gear above 71 mph so drive around in 7th most of the time. Having 5:38 installed later this week.

 

[JTGuy]

With my BFG KO2 37s the 4.88s are a great improvement over the 4.10s. I see 8th at 45mph on city streets.

 

[homerun]

these are well done and should be helpful







Mine is a 6speed and I will be going 5.13. I am also in Colorado and drive at altitude.

 

[Rottwheeler]

I recently installed 4:88's with my KO2 37"s (closer to 36"). I am very happy with their performance with and without towing my 17" Lance trailer. I will suggest going with Dana replacements. I chose another brand and have found them to be much noisier than my original gears.

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