the 12 jku I picked up had a readylift 4" lift kit on it when I got it from the dealer which mainly consisted of springs and sway bar extensions. My question is can I piece together the rest of the components needed to make it a strong suspension such as upper and lower control arms etc. from different company's like rock krawler or would you guys suggest I just get one whole tried and true kit instead of mix matching parts? Any help would be appreciated.

Yes you can. I have TeraFlex springs, Rock Krawler track bar brackets and rear bar, TeraFlex's version of the Anti Rock sway bar, Crown extended brake lines...

It's not uncommon to see.

No problem getting different manufacturers to build your Frankenlift. Something to consider is when companies match their triple rate/progressive coils to a particular shock valved for that application, but you can probably get around that with any coil and a Rancho 9000XL adjustable shock.

It's better to stick with arms all from the same company and use matching springs front and rear. As well as matching shocks front and rear (unless your are going adjustable).

Ok great I was going to get the rest of my parts from rock Krawler so the only thing that will be a different company are my springs. Any ideas what components I should get first?

Be careful with arms and the lengths.

I would do front lower arms at min (RK)!
Or front lowers and a rear set (uppers and lowers RK)
Rear track bar bracket (axle side)
Synergy, TF, EVO

Front track bar bracket and flipped drag link (Synergy sus.)

That should get you started... Good luck.

I have evo coils terraflex arms, JKS front track bar, BDS rear track bar, pro fender shocks, and I'm going to make sway bar links. It all works very well together and I'm happy with it.

RK arms and tie rod.
Synergy track bars, flipped drag link, front track bar bracket, sector shaft brace, upper track bar bracket and springs.
JKS rear track bar bracket and adjustable spring perches.
Rancho RS9000 shocks and front sway bar links.
Rubicon Express rear sway bar links.

Everthing plays very well together.

Teraflex springs, synergy rear arms upper and lower, rough country front lower arms, jks front trackbar, synergy rear trackbar, rancho shocks, rk bumpstops, synergy tie rod and draglink. My rig is nothing fancy but solid

This is very common. I would not worry about mix and match at all. Do what you think is best! It is your Jeep...

RK

I would like to add that you can't go wrong with Rock Krawler, Synergy, MetalCloak or JKS suspension/steering parts and Rancho shocks/drop brackets.

Have a plan before you start and research to make sure everything you choose will play nice together or just ask on the forum.

I learned that JKS adjustable spring perches only play nice with their raised rear track bar bracket the hard way.

Synergy's sector shaft brace/track bar brace won't work with all front track bars.

Rock Krawlers rear control arms come in 2 flavors: mid and standard. The mid arms don't play nice with stock arms and you can't mix their mid & standard arms. This only applies to the rear arms. If you run their mid arms you have to move your sway bar back.

there's no issue using someone elses arms with that lift. will be fine

great thread im in the same boat i just bought mine with 3.5 inch RE springs

All of Rock Krawlers arms are called Mid arms (except for their long arms of course)... Any how, You bring up a good point.

This is a problem somewhat unique to Rock krawler rear arms. Many arms have a larger diameter/ longer shank with more adjustment so they are usable with both stock lowers/ uppers and adjustable lowers/uppers. Others (Synergy or Metalcloak for example) have enough adjustment to go from stock to 1" + longer which makes them more versatile and you dont have to worry about spending money twice if you just get tje uppers or lowers ( they are all compatible).

Rock Krawler uses the rear lower control arms to adjust pinion angle in their Expedition, Flex, and Max travel kits. Using the lower rear arms to adjust pinion angle is counterproductive to both centering the axle and increasing tire clearance at the pinch seam and rocker guards.

RK doesn't really correct pinion with the rear lower shorter arm. I never really saw much of a point to the max Travel- running the short lowers at or close to stock. At least now, buyers have a upgrade path and can buy a stock length (shorter) set of uppers to run with the shorter lowers.
my rears were cut down on request but now you have the option to buy the short rears as a pair or upgrade the max travel,

A couple other things most are not aware of. if you look at the instructions the rear specs have been brought in and arms shortened 3/8-1/2".
I believe the shank size has increased too given you more adjustment past the jam nut.

In the expedition, Max travel, and Flex kits, only rear lowers are included so shortening lowers is your only option to correct pinion angle. If you don't shorten the lowers, you won't correct the pinion angle (unless you add to the kit and purchase uppers).

Even if there is a "path", it's still a limited path. You have to choose between 2 arms from the start. If you don't get the longer arms to start with, you have to repurchase lower arms after you already have them, or settle for the shorter arms and add the shorter uppers to match (or in your case have arms custom made). That's a limited path when you consider Synergy or Metalcloak both have enough adjustment that you don't have to choose between 2 different arms and you can still extend the arms 1" over stock. When your mixing and matching or building slowly, you need to have choices and adjustment to accommodate the next step.

What are the measurements on RK's arms (both sets) and how much adjustment do they have? Both the shorter and the longer?

You had to have yours cut down on "request", but other manufacturers arms would have given you the lengths you needed plus some to spare without any special request.

Did you have both upper and lower cut down?

I realize that concerning the short lowers. I don't remember the exact numbers. If you look at the instructions,the settings are stock or something like 1/8 in. The purpose of the short lowers is not to set pinion angle.
Yes both
Lowers set to 20 1/4
Uppers 18.5 i believe.

The upgrade path is either a stock length set like most others or moving the axle back.

I dont know what the min/max is on the new arms. Actually i am helping somebody with setup and will get the numbers from him (x-factor)
Mine ... I wrote the numbers down somewhere. I will try and locate them.

We offer 2 sets of rear arm packages. Our X Factor designed for flat fender use and properly centering the rear axle under most common aftermarket flat fenders.. Or our Flex Arm package which will work great for stock or Bushwacker pocket style fenders (Rear lowers part number - RK02064/ Rear upper part number - RK04852)

We typically do not like to allow too much thread to show exposed past the jam nuts because it is a strength concern.. The joint shank stress transitions from shear stress to more of a combined bending and shear stress with the more shank you have exposed, thus the greater chance of an issue or failure. We guard heavily against that situation....

Hope that helps and clarify some of the statements made above...

RK

Yes, they call all of them mid arms. I was making the point that there is a difference. RK should probably clarify it on their website.

Making it into a problem, because you have a hardon for RK is a different story. Since when are more options bad? Just because it confuses you doesn't mean it isn't a great solution. RK already pointed out why. I would not trust Synergy arms with overextended joints. I don't think it is a good idea with Metalcloak either

Maybe I am confused... What is the problem that you say the 2 choices in arms are the solution to? I haven't seen the min/max arms lengths posted anywhere by RK. Thats important to know when you start mixing and matching.

What are the min. and max. Measuremants on Rock krawlers arms? Both the shorter and the longer rear along with the front?

I never said anything about over extending Synergy, Metalcloak, or any one elses arms. Are you saying that the range that Synergy and Metalcloak provides is over extended?

Sorry, I will have someone format the file tomorrow so I can cut and past it right in here for all to see our recommended starting dimensions for all of our arm assemblies...

Does it really always have to turn into this? Shaking Head. No wonder why we spend less and less time on the forums as well as other manufacturers. UGH..

RK

Your recommended starting dimensions are easy enough to find. They are listed in the instructions. Starting dimensions do not provide the min./max length or the amount of adjustment.


What are the min/max lengths of your arms?
How much adjustment do your joints allow for?


Seems like simple enough questions that may shine some light on any confusion. Many/most manufacturers have that basic information readily available so their customers know what they are getting.

What are Synergy and Metalcloak minimum & maximum recommend lengths? I have not seen them listed on their sites or in their directions. Since we are talking about RK mid arms moving the axle back I don't know why minimum length important especially since RK offers arms that address stock length. RK does not suggest more than an inch of thread to be visible on their lower joints, I know their maximum extended length on the longer arms is about 22.5 inches with that limitation. Both MC and Synergy recommend running their lowers at about 20.5 inches, so if you want to run their arms as long as RK's then I believe they would be overextended. RK gives you the choice of running stock length up to about 2 3/4 inches of "stretch".