Just looking for a little advice. The jeep is a 2016 JKU automatic. Currently I am running a RK 3.5 max travel, Method NV wheels, and BFG KO2 37s. Only armor I have at the time is a Hanson stubby stinger bumper but will be adding rock sliders and probably dropping the spare tire or saving for a body mount tire carrier. Soon I will be finishing the lift adding front and rear upper control arms, rear track bar, upgrading to steer smarts yeti drag link and tie rod, and adding a front track bar bracket if needed depending on axle.

First question is what gears would be best for my jku with the 3.6 and automatic with the KO2 37s. Everybody knows they are more like 36s when mounted and they weigh less than the majority of 35 inch mud terrains at only 70 ish lbs a piece. I was thinking 4.56s but after i upgrade the axles with lockers i think i would more likely need 4.88s. Also I live in Florida which is mostly flat and dont do any super serious offroading.

Second question is because the KO2s are smaller and lighter do i need to upgrade to a 44 front or can i just build up the dana 30. Options right now are build the 30 with artec truss gussets and skids, carbon axles, teraflex ball joints, and track bar bracket. Or buy the new spicer UD44, lock and regear the rear to match. Or buy and build a J8 axle with artec truss kit, carbon axles, e lockers front and rear, teraflex ball joints, and track bar bracket.

Any info or advice is much appreciated. Hopefully someone with the same tire setup.

 

There are so many threads on building D30 vs going D44 that my head hurts even starting to get in to it. I’m going to leave that to others if they want argue till the cows come home.

From what you’ve described, I think you’re on track with the 4.56’s. If you don’t do any serious offroading, is there a reason you feel like you need a locker up front? You could very easily add some gussets to at least give your C’s a little extra support, regear, and roll on. If you feel you need it, maybe just look at a locker for the rear since re-gearing anyhow and since a locked D30 up front can lead to issues down the road. Your jeep is probably more capable then you imagine, and it’s just not worth putting a lot of money in to a D30……but also doesn’t sound like you really need to upgrade for your use unless you have a really nice budget to play around with.

 

I have 2016 Rubi , auto and run factory wheels with Toyo 285/75s. No armour, just rear bumper/carrier assembly. Rest is whatever comes in Hard Rock edition.

I regeared to Yukon 4.56, from 3.73 and WOW!
Now granted my tires are 33 1/4 mounted, and total weight per assembly is 83lbs.
Take it for what it's worth, but 34-35s seem to be 4.56, and 37 are favored with 4.88. I'm in the Midwest

 

Even with relatively flat surfaces in Florida, you can still bend up a D30 with big tires and wheels like you're talking about, even with them being "lighter". When you add up all of the money you'll spend on building up a Dana 30, including the labor costs (critical to keep this in mind) you'll be a stone's throw away from just buying a full 44-based aftermarket axle. Another thing to keep in mind, say you spend the money to upgrade the D30, when it brakes (when, not if) all the money you spent to build it up will be flushed down the toilet. And going with a 44-based unit like our ProRock 44 (https://www.dynatrac.com/axle-assemb...k-44-axle.html) will give you more gears to choose from to work with your larger wheel/tire combo, along with the added strength and reliability of the unit. And it is a solid investment in your Jeep.

 

I definitely am interested in the Dynatrac trail leader package some day if my pockets can allow it. That package is exactly what I want and need since I have no interest in 40s. My next set of tires after I figure out my axle dilemma will be STT PROs in 37s.

 

bump bump

 

Bump for the same question? Throw the 4.56 in there, and if you're not wheeling it hard don't even bother throwing the truss and gussets on. Just don't drive it like a prerunner.

 

The trail leader package is actually a good kit if you plan to keep the stock rear 44. The only thing you would really need to do is truss the rear 44 to really complete the upgrades.





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I just completed the same upgrade, mine is a manual though. I have 37 Cooper STT, but I dumped the D30 for a set of Rubi axles I got a really good deal on Craigslist for and built them. I have synergy sleeves, artec gussets(they are thicker than the others I could find). I run 4.88 and its relatively flat where I live and they are perfect. If you aren't going to wheel the D30 will be fine, but if you are going offroad start saving for a better axle.

 

You need to be realistic on how you plan on using the Jeep, and go from there. I personally wouldn't waste a dime on a D30. If you plan on keeping the JK long term, I recommend just saving up for a ProRock 44 with Prosteer ball joints. It is an awesome axle for 37" and under tires, and you are investing in long term durability. I never understood buying other aftermarket axles and then having to truss them or add gussets to make them stronger. Buy once and be done. Also, 4.88's are a great all around gear for 37's. Being that you will run a smaller 37, that is the way I would go.