37s & Regrets?

[c20040215]

Ran 37s and 3" lift on our 2019 with stock 4.10 gears and 2.0t for 35k miles. Never a lack of power or any desire to regear. Went to 38s and there were a couple times in 4h that it wanted to bog in reverse (deep snow and sand). Decided to regear and since I was spending $3k to do it jumped to the deep end with 5.38s. Worst decision ever. Jeep was actually a half second slower 0-60 as it had to make an extra shift geared that low. Freeway rpms were too high. Lost fuel economy by 2 mpg. Save your money on the regear unless you're towing a trailer. Stock gears are fine on road and great even in the big rocks with the 4-1 low range.

Regearing to an overly aggressive ratio for the tire size is a bad idea.
For 37s/38s, most people go with 4.88 or 5.13 and see positive impact on performance and fuel economy all around. Have you driven one that is more properly geared?

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[Zandcwhite]

Regearing to an overly aggressive ratio for the tire size is a bad idea.
For 37s/38s, most people go with 4.88 or 5.13 and see positive impact on performance and fuel economy all around. Have you driven one that is more properly geared?

Yes, driven Jeeps geared all over the spectrum. I find especially with the double overdrive in the 8 speed and its super low 1st gear I prefer things geared on the higher side. Our 2022 XR felt like it was geared too low stock with the 4.56s and 35s. It's now on 39s and although I think 4.88s would be more optimal I'm in no rush to regear. It's a simple cost vs benefit scenario for me. Crawls great with its 88-1 crawl ratio, it's plenty quick off the line, and it will cruise 85mph all day long and won't be spinning 3k rpms like the last one. My new '23 JT is on 37s now and the 4.10s are more than sufficient. There for my driving style 4.56s would be better, but not enough so that I'd drop $3k on it. If I need more power a supercharger is only a few grand more than that and will actually deliver more power not just more rpms and the illusion of power that comes with it. If you want to know how your 8speed with 4.10s would drive with 5.13s, downshift to 7th gear every time your see 8th. It's an identical final drive ratio. Aside from 1st gear, lower gears don't offer any advantage over simply downshifting in my experience, and the 8 speed does a great job of that on its own.

 

[c20040215]

Yes, driven Jeeps geared all over the spectrum. I find especially with the double overdrive in the 8 speed and its super low 1st gear I prefer things geared on the higher side. Our 2022 XR felt like it was geared too low stock with the 4.56s and 35s. It's now on 39s and although I think 4.88s would be more optimal I'm in no rush to regear. It's a simple cost vs benefit scenario for me. Crawls great with its 88-1 crawl ratio, it's plenty quick off the line, and it will cruise 85mph all day long and won't be spinning 3k rpms like the last one. My new '23 JT is on 37s now and the 4.10s are more than sufficient. There for my driving style 4.56s would be better, but not enough so that I'd drop $3k on it. If I need more power a supercharger is only a few grand more than that and will actually deliver more power not just more rpms and the illusion of power that comes with it. If you want to know how your 8speed with 4.10s would drive with 5.13s, downshift to 7th gear every time your see 8th. It's an identical final drive ratio. Aside from 1st gear, lower gears don't offer any advantage over simply downshifting in my experience, and the 8 speed does a great job of that on its own.

Good to know. Everyone has different options and preference, but 4.88 is still the optimal according to you.

 

[Zandcwhite]

Good to know. Everyone has different options and preference, but 4.88 is still the optimal according to you.

For 39s yes, for 37s I'd stick with 4.56s.

 

[kah.mun.rah]

Before I take the financial plunge…
21 JLUR 3.6 Auto.
Planning on AEV 2.5 lift with 37’s.
Currently running stock 4.10 gears. (Looking at 4.88 down the road)

I feel like with all the info out there, there isn’t enough.
Any regrets to going 37? Or running 37’s on a 2.5 lift?

As always, much appreciated.

My only regret was buying 35s 1st before going to 37s. I am running a 21 JLUR 3.6 Auto with a 2.5" lift with 37s and stock 4.10 gears at sea level and love it!!!

 

[C.Sco]

My only regret with buying 37's was not buying 38's or 39's

The 37's have been awesome though. <---- see my avatar pic!

 

[CarbonSteel]

Decided to regear and since I was spending $3k to do it jumped to the deep end with 5.38s. Worst decision ever.

Well, yeah. Because you overgeared a turbocharged engine that did not need it.

4.88 or 5.13 would make a lot more sense for that engine and tire size combination. You needed to do more due diligence before "jumping into the deep end".

 

[wranglerbro]

Hi. Can you share which of the Bilstein's you paired with this on your 4xE? Btw, Sahara/Rubicon/HA trim? Sahara here.

Of course and nice choice picking up a Sahara!

For the Rancho 3” lift on my Rubicon, I’m running Bilstein 5100 B8 2-3” shocks (front and rear). The ride is super compliant and predicable, the shock/spring combo handles the 4xe’s weight with ease, and the rebound is much quicker than the stock shocks were (but not jarring). They’re also super cheap to replace if one has an issue.

The Rancho Lift kit plus all the shocks ran me $879 shipped during a sale. I grabbed the extended length Mopar LCAs for $70. IMO, it’s a great setup for $1000.

 

[Mordraq]

Thank you! For the many many posts we have on here, finding good setups that are tested on the 4xe has been a challenge at times.

I had some warranty issues in the first 10k miles and the dealer was really pressing on unwillingness to help if I had installed anything aftermarket, so I’ve been gun shy. Though others say that shouldn’t be an issue.

But soon the warranty will expire and I’ll be out of excuses ?. Likely will just run 35s as with Sahara I’m guessing I’d want a regear above that. Frankly we don’t do anything too crazy anyhow, but a couple inches more would have been nice a few times!

 

[roaniecowpony]

For 39s yes, for 37s I'd stick with 4.56s.

I went to 4.88s with my 36.5" 37s. Absolutely perfect for me. Freeways are great. Everything from Rubicon to Golden Spike was also perfect. I love this gearing and it would be great for a daily driver...if I daily drove. No more compulsory I-405 commutes for me.

 

[rohdawg]

a couple inches more would have been nice a few times!

 

[wranglerbro]

Thank you! For the many many posts we have on here, finding good setups that are tested on the 4xe has been a challenge at times.

I had some warranty issues in the first 10k miles and the dealer was really pressing on unwillingness to help if I had installed anything aftermarket, so I’ve been gun shy. Though others say that shouldn’t be an issue.

But soon the warranty will expire and I’ll be out of excuses ?. Likely will just run 35s as with Sahara I’m guessing I’d want a regear above that. Frankly we don’t do anything too crazy anyhow, but a couple inches more would have been nice a few times!

Service departments are so hit or miss man, but good ones do exist. I just took my Jeep in this week to have the ECH replaced and it was covered without question, though I'm fully aware they won't cover the suspension parts I've replaced. Makes sense to me and wasn't enough reason not to do it.

As for gears, I'm not overly convinced that they're needed with the torque the 4xe battery provides. Having spent a lot of time above 10,000 feet in this thing over the past two years, I haven't really found myself pining for more. BUT...if I ever were to re-gear, it would likely be 4.88.

Here's a pic of the lift after I installed it with Baja Boss M/Ts (it's a bit too clean in the photo):

 

[wibornz]

If you've done the trackbar, steering box TSB, replaced the trackbar with a good aftermarket, balanced the tires, etc., it may be your balljoints. It was for me anyway. The factory balljoints just flat die. Mine did so around 20,000 miles of street use. Dynatrac balljoints fixed it. YMMV.

I just re built my Dynatrac ball joints. I put about 70,000 miles on the Dynatrac before they needed to be rebuilt and that is with thousands and thousand of mile off the road. So they are about double for life over the stock ball joints.

 

[wibornz]

no.
well, maybe when having to lift the 100lb spare back onto its mount. ?

aside from the expected regearing and dealing with LCA and rear fender well rub and the decreased braking performance (and forgive me if you are already aware of this, but i haven’t seen it mentioned be prepared to budget for a Spare Tire Carrier and CHMSL Relocater to deal with that larger spare.

All of those things for sure. I figured that going to 37s on my cost me the following.

$4500 for my wheels and tires
$800 for the Rancho lift
$1600 for the upgraded steering components
$900 for my spare tire carrier
$660 for the Dynatrac ball joints.
$2200 for gears and install. Note I did all the other installs. Also Note, I work cheap for myself. I charge my self a decent steak and a good shot of bourbon at the end of the day.

Some might say that is a bunch of money, yet the memories and view are priceless.

Like has has your wife ever hung over the edge of a 1000 foot cliff by the front bumper of your Jeep kind of memory.

Notice my bud stacking rocks at the passenger rear corner. My wife almost flipped the Jeep over backwards right here.

One does not create memories like this sitting on the couch watching Family Feud. Lift the Jeep buy the tires spend the money and go wheeling. There is so much to see in the is country.

 

[wibornz]

Yeah.. the biggest regret is I should have gone bigger.
Put 37 Nitto ridge grappler two months before they came out with 38x12.50R17.. I am still mad.

37s should work great with you set up. Regear to 4.88 is a good move.

If I lived in Florida, 4.88 would be a great choice. For the times that one might want to go to 5.13 would be far and few between.

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