CelticMonster

How's it going everyone. I just picked up a 2013 JKU Rubicon and ordered new wheels and tires for my rig (17x9 w/ 4.5" backspacing American Outlaw Buckshot rims wrapped in 315/ 70 R17 BFG All Terrain T/A K02s). I was wondering what I need to do to ensure nothing breaks. I've already done some digging and know I need gussets at the bare minimum, but I'm getting mixed opinions on the rest. Another thing I'll add is that I will most likely be going with a 5.13 gear ratio as well.

What's the consensus... axle sleeves, Truss? Both? Front and/or rear? I'm curious on your thoughts as to what should be done.
This rig is my daily driver and weekend warrior. Use should be moderate- moderately heavy trails but nothing like rock crawling or anything too extreme. I appreciate any info you guys have.

RiverCityOffroad

You are going to get a ton of input here. Here is my advice which comes from both personal experience and helping customers build Jeeps for the last decade.

Gussets are cheap insurance, but plan on doing ball joints at the same time (after welding) because the heat that welding creates will melt the internals on the stock ball joints.

I personally prefer a truss over sleeves, but lots of guys are running both. People may say that a truss won't strengthen your axle...that is bologna. If welded properly the added backbone adds lots of strength. There are many choices for a truss from Artec, Synergy, Evo, ect. All of those companies also offer gussets.

5.13 is a lot of gear for 35s...I'd look at that closer and consider a 4.56 or 4.88 if you have an automatic. 5.13s are great with 40s, but that 3.6 will be spinning a lot of RPMs with 315s and 5.13 gearing. I personally prefer a 4.56 in a 3.6/auto with 35s.

Run the stock axle shafts until you have an issue. You may never have one if you wheel the Jeep like you have to drive it home.

Welcome to the forum and welcome to the Jeep world! Good job doing some research before you spend any money!

Marcus

resharp001

You're going to get a lot of people say don't bother building it, just go with an aftermarket axle. I'll give a perspective from someone who built up a Rubi 44. I've got gussets, trussed w/ TB mount, regeared, upgraded LCA brackets & shock brackets, and pricey ball joints. Sleeves are worthless, and a truss is probably false sense of security (for what it's worth). If you're doing the work yourself it can make some sense. My costs were kept in check as I didn't have to pay for someone to do all the labor. At the end of the day you'll still end up with a weaker Rubi locker and tubes vs. a beefy after market unit that is going to have substantial bracketry all around, a better locker, and thicker tubes.

If you're only doing easy/moderate things, you could probably get by just throwing gussets on and calling it a day.

If you really want it built, and it's adequate for you and you can keep costs down, might be worth it. Generally looking at $750 (parts/labor) to regear an axle, $60 for gussets, $160 for truss and TB.....and cost to weld if need be. If you go that route, I'd just pay the extra $50 for new 1/4" CA brackets and the small bit for 1/4" shock mounts as well and weld them at the same time. Once you weld on gussets, you aren't able to outboard shock mounts very far as the lower gusset is in the way.....and you're probably going to want those outboarded some.

Dynatrac

A big thing here is what kind of budget you're working with to mod your Jeep? Yes, you can truss/gusset your factory axle and sleeve it too, but those are all still Band-Aid fixes on a weak factory axle. And since you've got a Rubicon, you have to deal with finding Rubi specific parts. Before spending any money, add up all you would spend on beefing up that factory axle (don't forget labor cost) then weigh that against buying an aftermarket axle setup that will give you more strength and capability. What you see will surprise you. Even if you don't think you'll need it with the level of off-roading you're planning on, it's better to have more capability in your Jeep than just enough. You never know when that moment will come when you push your Jeep harder than normal, or if you'll want to step up your game later on.

Past that, with larger wheels and tires you should definitely upgrade your ball-joints to something like our HD Ball-Joints (https://www.dynatrac.com/rebuildable...alljoints.html) that will give you all the strength you'll need and can be rebuilt whenever necessary without having to without the need for major disassembly like with a full ball-joint replacement.

Finally, upgrading the brakes on your Jeep would be a smart move no matter what. Adding the extra rotating mass and inertia of those bigger wheels and tires can overwhelm the factory brakes. Our ProGrip kit (https://www.dynatrac.com/brake-syste...e-jeep-jk.html) allows you to get way more out of the stock calipers, doesn't require bleeding so you can do the install yourself, and will give you more stopping and holding power on the trail, plus the benefits of more stopping power when you're driving your Jeep on the street. You can see the difference it makes in the video at the above link.

CelticMonster

Thanks guys, I appreciate it. I know, at least for the next few years, I will be keeping my current axles and just want to beef them up more.

So it seems like gusstes are a definite, truss possibly, but new ball joints too? I guess I need a little more info on that. It's tricky because I'm learning all about my Jeep as it currently stands as well as upgrades.

Gears... this is definitely a point I need to further research further. I've heard 4.56 being optimal, as well as 4.88... and then the Modified FAQ here says 5.13, so there's some confusion in my mind.

resharp001

Factory BJs are crap. If you have bigger tires and wheel, you'll be upgrading. You got the $200 to $250'ish range BJs like Synergy, Teraflex, Alloy......and then you have pricey Dynatracs and Rare Parts in teh $500+ range. MOST people probably fine with the $200+ BJs. I did not have luck with several sets of Synergy. I'd give the TF a try over those others in that range. I personally have Dynatracs cuz got tired of dealing with that job. As marcus highlighted, best to just do this when you do gussets.

With the 3.6L, 4.56s would be the sweet spot for a 35" tire....4.88s leaning on the aggressive side. for 37s 4.88s are the sweet spot with 5.13s on the aggressive side. If you have 4.10s, it's not terrible with 35s, and prob about perfect for a 33. All depends on what you're running.

RiverCityOffroad

See my post again: "Gussets are cheap insurance, but plan on doing ball joints at the same time (after welding) because the heat that welding creates will melt the internals on the stock ball joints."

If you do the gussets, plan on the ball joints failing more quickly than they might have without them. The internals on the stock ball joints are plastic, welding creates a ton of heat, and can melt the internals making the ball joints get sloppy. Stock ball joints are junk as it is and are a VERY common upgrade for the JK.

The JKs started out in 07 with a 3.8L motor and ran until 2011. That motor requires all of the gearing you can throw at it to turn big tires at a marginal comfort level. Haha! The newer Jeeps, 12+ have a 5 speed transmission and the 3.6L motor which makes for a much better final drive ratio, so you don't need the deep, deep gearing like we did in the past. That is likely why the FAQ says 5.13.

Marcus

resharp001

These charts are very accurate -



You're never going to hate the low end power on anything....but the RPMs at highway speed get aggravating. You can force your jeep in to a gear that has you cruising at 3k RPM at 75mph and get a taste what that is like. 2400-2700rpm at cruising speed is typically were people shoot to end up.

CelticMonster

You guys are awesome, thank you for all this information. Like I said earlier, it’s tricky both learning about Jeeps in general as well as upgrading them at the same time, but I’m absorbing as much info as I can!

Seems like right now, my ideal (minimum but safe) set-up would be gussets, ball joints (teraflex or dynatrack), and 4.56 or 4.88 gears (still debating which, I have an auto transmission). And then as funding allows, upgraded brakes and possibly axle truss.

Little side tangent, but as a daily driver and weekend warrior, which gear ratio and why? I know I just opened up another can of worms...

resharp001

My set up has me traveling ~3k RPMs on the interstate. It's bearable for me, but more aggressive than most would like, and I wouldn't suggest it for a daily driver unless you were in the mountains and didn't drive 70+ mph on highways and such. My fuel economy sux pretty bad. ~13.5mpg round town. I can eek out 15.5mph if i drive 65mph on the highway, but anything over that the gauge drops fast. That said, I get offroad benefit from the lower gearing.

You haven't really said what size tires you're thinking, and it will all revolve around that. For 35's, daily driver, easy to moderate off roading, AND considering you have a rubi TC.....almost all signs will point to 4.56. Having said that, typically you need to jump 2 stops to make the upgrade worthwhile financially. If you hav a Rubi with 4.10s, you might just choose to survive on them. If you have 3.73s, it would be worthwhile. Again, all of this depending on tire sizing.