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does not perform as expected, need advice

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Old 06-05-2018, 08:14 AM
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Default does not perform as expected, need advice

So I am on my sixth jeep CJ/Wrangler. I just moved to Cheyenne Wyoming so we decided to try some of the northern colorado trails last saturday.
My jeep had some issues with the trails. I currently have a 12 wrangler sport 2 door with 321 gears and 33 toyo at's and a 6 speed. I always wanted a red jeep and the 2 door offers better maneuverability in the thick forests of Northern Idaho and Western Montana, where we moved from. On the trails last weekend I was unable to keep the speed down without almost killing it on multiple climbs. I am not a point and gun it kind of offroader. I prefer to slow crawl and finesse my lines. I simply could not do it in this jeep. So the big question.
Now that I live where I do and will be on Colorado and Moab trails, should I regear my sport to 4.10s or just save the 3 grand from the

gears and a locker and get a wrangler with an automatic? Maybe an automatic and a diesel!
Old 06-05-2018, 08:55 AM
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Outside of this performance, you're still 100% happy with the jeep? You plan on keeping this till it dies? Do you see you're off roading adventures getting more aggressive?

Spending a couple grand on a 12yr old jeep, that is going to allow you get get much more use/life out of it....along with a big payoff of enjoyment, isn't the end of the world. It is surely a lot cheaper than buying another jeep! Not sure what regears cost in that area, but $1500 +/- would be well worth it. Even if you added a front or rear locker, it's still realistic. If gears and lockers would then make you feel like you need to beef up your axle and driveline, then you start to get past that tipping point. It sounds though like you're wheeling is more generic outdoor adventures and you're not out trying to crawl boulders. Just need to regain a little power from that 3.8L and high gearing. Would a recovery items like a winch be an option rather than lockers? Are you getting stuck a lot of places cuz a wheel isn't getting turning?
Old 06-05-2018, 09:23 AM
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its a 2012 jk..tons of power. My main issue is with the clutch and 321 gears I found that I was either spinning tires or stalling out the engine. There seems to be no inbetween.
Old 06-05-2018, 09:28 AM
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Originally Posted by ldstruckn
its a 2012 jk..tons of power. .
somewhere along my train of thought i got sidetracked thinking 12 years old, not a '12. LOL. duh. That wouldn't even be possible. Sorry.
Old 06-05-2018, 09:40 AM
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Originally Posted by ldstruckn
its a 2012 jk..tons of power. My main issue is with the clutch and 321 gears I found that I was either spinning tires or stalling out the engine. There seems to be no inbetween.
I'll tell you that with a stock '12 Rubicon with the 6 speed, 4.10s and the low ratio transfer case I could barely stall it during a low speed crawl if I tried. The issue isn't the stick, it's the gearing. I'm on 37s now with 5.38s and even though it's slightly more prone to a stall while crawling at idle, I certainly wouldn't give it up for an auto. Your gearing, at both the axles and the transfer case, are about the least crawl oriented that you'll find in a JK. I'd say keep the stick if you like it, upgrade the gearing and swap out for a Rubicon transfer case if it's not enough.
Old 06-05-2018, 10:05 AM
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Originally Posted by icrashbikes
I'll tell you that with a stock '12 Rubicon with the 6 speed, 4.10s and the low ratio transfer case I could barely stall it during a low speed crawl if I tried. The issue isn't the stick, it's the gearing. I'm on 37s now with 5.38s and even though it's slightly more prone to a stall while crawling at idle, I certainly wouldn't give it up for an auto. Your gearing, at both the axles and the transfer case, are about the least crawl oriented that you'll find in a JK. I'd say keep the stick if you like it, upgrade the gearing and swap out for a Rubicon transfer case if it's not enough.
We'd agree with this assessment. If you've already got the tire size your sticking with for a while and the power "isn't where you want it", start with a regear and go from there.

-Kyle @rebeloffroad
Old 06-05-2018, 10:32 AM
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Here's some thoughts... First the math: 4.10/3.21 = 1.28 So with 4.10 gears it would have 128% of the current wheel torque with 3.21 gears. And it will be going 78% the speed for the same RPM. That's quite a bit of added torque, and it won't change the MPG much -- mine gets 19 on long highway trips and it's the older 3.8L.

To me, the tipping point for trading Jeeps would be if you think you want even more torque -- like a Rubi xfer case (4.0 vs 2.72 = 147% lower in lo-range). Changing to 4.56 gears in the diffs might be worth considering for a bit more torque than 4.10, but you've had a Rubi before so your familiar with how much lower it is in lo-range. As IcrashBikes mentioned, a manual Rubi in lo with 4.10's and 33's is almost un-stallable.

To me, automatic transmissions are better in sand dunes (quicker shifts), starting up steep hills, and high water (no clutch to get mucked up). Manuals have better clearance and engine braking. Only a little time driving an auto, but I'd probably use lo-range less because of the torque convertor slip.


Last edited by Mr.T; 06-05-2018 at 04:57 PM.
Old 06-06-2018, 09:45 AM
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So I didn't notice if you said you're in 4HI, 4LO, or 2WD? I suspect (if I'm wrong, my apology) that you're in 4HI... betting if you drove in 4LO you'll get what you're looking for?
Old 06-06-2018, 01:03 PM
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4LO. seems that a regear is more in order. I have been waiting for the new diesel jl to come out but also planned on keeping the jeep for my son to inherit since it has a stick (and every man needs to learn on a stick). Right now I get 20-21 mpg highway as long as I stay at 75. I would love to keep close to that (since everything is down an interstate from me) but gain the slow crawl ability so I am leaning toward 4.10's, 35's, and some axle bracing.
Old 06-06-2018, 03:35 PM
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Honestly, really don't need much bracing besides some gussets to help reinforce the C's. Truss is overkill for what you are likely doing, and sleeves are not worthwhile. Perfect time to swap some BJs if you do gussets.

4.10s with the manual wouldn't be bad. With the Autos, 3.56 is the sweet spot for 35s and 3.6L.


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