So this is my first time doing any type of build with any type of vehicle. Here's a little background. My Jeep is a '16 JKU Rubicon. My plan is to do a 4" Currie lift on 37" Goodyear MTRs. This is my DD but I would like to travel around and run trails maybe once a month or so. I wouldn't be going hard when I'm off roading, on a scale of 1 to 5 on how hard I would go would probably just be a 3. Not going to do any intense rock crawling or anything.


1. There are 2 types of kits that I'm looking at on the Currie website. I was planning to buy the Rancho 9500xl shocks with either kit. Once includes the upper controls arms with the lower. The other just has the lower control arms. My question is for what I plan to do, are the upper control arms necessary or will stock ones be ok? It's about $800 more for the kit to include UCAs. Also read that people use stock but use some type of correction brackets. Can I even just get the UCAs later?

https://www.currieenterprises.com/ce...pension-system (HAS UCAs)

https://www.currieenterprises.com/CE-9807S (NO UCAs)


2. Obviously gearing will be done but does 4.88 gears sound right? I've read people mostly use that set. I've seen 4.56 and 5.13 as well. Mostly in town driving at 55mph zones.


3. Is there any other types of upgrades that need to be done with a set up like this? I was told steering by the Currie representative but said I should be good other than that. I am reinforcing the axles with axle truss and doing c gussets. Some say sleeving isn't worth it, but should i just do it anyway?


If there's any other info you guys need from me just let me know. Thank you!

 

If you haven't already, open the two threads stuck right to the top of this modified area. There is some good background info in there.

A single set of control arms allows you to adjust the caster/pinion by rotating the top or the bottom of the housing a small amount. The second set allows for more fine tuning, as well as the ability to move the entire axle forward/backward in the wheel well. As the lift gets taller, the stock control arms bring the axles closer together, reducing wheelbase by some amount. A single set of arms does not address this, so the second set can become more important as height increases. Do you HAVE to have both upper and lower? Nope. But as a suggestion if you go this route, do the front lowers and rear uppers, as those two sets get adjusted longer than stock. Can a second set be added later? Of course, whenever you get around to it.

Control arm brackets generally have positive reviews. In addition to caster correction, they also address the steeper angles the front arms are at after the lift, which is an added bonus. Can you run brackets and adjustable arms? Certainly. Many of the brackets come with multiple sets of holes corresponding to 2.5/3.5/4.5 inches of lift, so you don't actually need new arms at all. Just put some thought into where you want to end up before indiscriminately buying parts.

Do a lot more reading before you dive into tearing apart and welding on the housings, as paying parts + labor can start adding up quick. Maybe come up with a spreadsheet that lists out all of the costs, both parts and labor, for various axle mods + gearing, and compare that to a few aftermarket offerings + the sale of your current axles. Not trying to talk you directly into dropping 10 or 20k on new axles, just a suggestion to educate yourself on all of the options so you go into it with your eyes open.

At that height, start putting money aside for a new front driveshaft.

** Spend a little time researching opinions on Drop Pitman arms. Look into a few of the draglink flip setups as an alternative.

Research Brake upgrades (both Rotor-only and Rotor/Caliper options), and at least consider longer lines if you choose to keep them stock.

Research the various other steering components and aftermarket ball joints.

Have you considered a shorter lift, with flat fenders?

Whatever else I'm forgetting...

 

I did read the first sticky. I'm new to most of this so there were a good amount of things i didn't understand yet. I'm researching a lot of the things as I go.

Well I think I may just do the single set of control arms for now and add the other set when I am able too. It shouldn't be more than 6 months before I get the other sets of control arms. Are these the type of correction brackets I will need?
https://www.northridge4x4.com/part/c...8aAuF4EALw_wcB
If its only that price I will probably get them and add control arms to them.


For the labor portion on the welding it will all be technically free since my brother will be doing all the welding. If it wasn't for him doing it, it would most likely push me to get new axles. I appreciate the suggestion though.


I'll put the driveshaft on a list of things I need to get then. I've read with 37s its strongly recommended for big brake job so that'll go on list as well. Steering and heavy duty balls joints are on the list too.

Thank You!

 

So I just read the other sticky, the one with the Q&As. That was extremely useful. My bad for not reading that first!

 

Someone just asked this question a week or so ago and a good list of what you're getting into was attached. Should be pretty recent if you can find it. We all want you to succeed, but there is a lot to learn. You can avoid a lot of painful issues if you're patient, realistic about your goals, and do plenty of homework. Anyone can hack together a rig that rolls on 37s, but to do it right and to satisfy your particular requirements takes some effort.

 

Awesome I'll check that out thank you

 

Here's the thread mentioned above -

https://www.jk-forum.com/forums/modi...0/#post4335382

If you're not going to be rock crawling, a truss will just be overkill. Y, it might not be a lot of money since you have help doing it, but it does eat up time. Slap some gussets on and replace the ball joints right then to save yourself some heartache. 4.88s will be the gears for you.....no need to do 5.13s, specially since you have the rubi TC. 4" isn't necessary, nor really advisable IMO. Taller isn't better, and you don't need it to fit 37s. Also, not sure if they've improved, but MTRs used to be notorious for having balancing issues. You need to look at more brands of lifts and really compare things. Open up the wallet....this build is gonna set you back some to do it properly.

Oh, and a lot of people really like those shocks. Just make sure you buy appropriate length shocks. It's really hard to go just by "for X to X size lift" as every single jeep is different. Also, if you go with those shocks, orient the rear ones so the adjuster knob is towards the axle. The knobs are prone to getting knocked off the other way.

 

 

More height also means more air passing under you on the highway which usually doesn't help. Also though, since you're sticking with rubi axle, you're stuck with 6* caster built in to the axle. You're likely to be going with a DC driveshaft, and the higher you go, the finer the line is of having an acceptable caster that feels good and that your DS enjoys as well. I don't look at currie lifts much, and they're not mentioned a ton. You might just read on on other's experiences and see if you should expect those springs to net you a decent bit more actual lift than the stated 4". That is where the real pickle begins. That's kinda a dilemma anytime you're swapping a spring though. Just things couple more things to at least take in to account when making the decision.

 

It's your jeep and your money, build it to suite your tastes. But you made a good call on researching and asking for opinions before just pulling out the credit card!!

For the front driveshaft, I don't have a handle on clearance issues with the 2012+ model JK's. But just from a maintenance standpoint, make a habit of crawling underneath and looking at the joint at the tcase end of that front shaft. It's the one that always gives the problem. And it'll be super easy to see when it starts to go, as there will be a big ring of grease being slung up on the undercarriage above the joint.

As resharp noted, once you move to a DC driveshaft, taller lifts will have a balance between good caster (better onroad handling) and good pinion (no vibrations). Using the arms/brackets to raise the caster after a lift automatically lowers the pinion, which of course sharpens the angles on the joints at both ends of the driveshaft. if you find yourself in that situation, worse handling is better than vibes or binding joints or an exploding tcase...

And note the Drop Pitman comment from my earlier post, as both of the lifts you are looking at come with it.