Adjustable Control Arm help
 

Just got upper/lower adjustable CAs. Can one of you fine folks help me with the install of them? Lift is 4.75" - Lower CAs are Synergy, Upper CAs are Metal Cloak.

What'cha needing help with?

Well, kinda all of it but, for starters, What is the correct amount of caster? Second, what should be my initial arm lengths when installing?

Do you have a stock front driveshaft, or a double carden? If stock then go back to factory spec of 4-4.5 degrees caster. If double carden, then try 4 degrees and reduce the caster/increase pinion angle until driveline vibes disappear.

Length wise, did the arms not come with instructions? If not, start with 18.75" on the uppers (stock length), and 23.25" on the lowers. Then take it to a shop to have it dialed in. Those measurements should get you pretty close though.

You can either take it to a 4x4/offroad shop and pay $200-250, or whatever the rate in your area is, for a full alignment (control arms and toe-in), OR, you can take it to a tire shop/Firestone/anywhere with an alignment rack and get a read out. Then take it back home, adjust, and go back for another readout. My local Firestone is cool, and since I have Lifetime Alignments they let me get a readout whenever I want so I went with the latter. Took 3 tries but I got it spot on.

Double Carden, came with instructions for the arms but, really worried about any driveshaft vibrations.

This isn't an exact science by any means. Here is a link to Metalcloak's installation instructions for one of their Game Changer kits. I'd imagine that given your 4.75" net lift, you're going to be close to what the lengths would be for their 4.5" lift.

http://www.armoredworks.com/metalclo...OX-Edition.pdf

See page 11 of that documentation for suggested lengths. Mind you, they are suggesting those lengths to achieve 5* caster, but it's a starting point at least. Since net lift will be different from jeep to jeep, and your 4.75" lift will be different anyhow, it usually takes 2-3 times to get things dialed in. I'd think the suggested lower lengths should be pretty close to spot on for you. Again....look at the lengths for the 4.5" lift.

What resharp001 said. That'll get you in the ballpark. Then take it for a drive. If it feels twitchy, then you have caster set too low. If you have driveline vibration, then caster is too high. Might be worth putting on an alignment machine to get the readings as well.

In general, that seems like a lot of life for a short/mid arm setup IMO.

Like Bora Bora, I have a lifetime alignment at Firestone. Think it cost me $140 years ago. Could go in every single day if wanted to deal with it. You can read your caster at home with a cheap angle finder, but I've found a decent degree of error. It gets you close enough and then gives you a baseline from which to make adjustments at home. Take it in for an alignment and then adjust at home as needed. Keep your alignment printouts and make note of any adjustments you tweak so you can remember what you did and when.

Why is it to much lift for it? Should, I go long arm? Lower it an 1"?

Just seems like up there around 5", the angles of your arms are getting pretty steep....and you start venturing in to long arm territory. Here's a decent pic to illustrate:

https://cimg9.ibsrv.net/gimg/www.jk-...44bb5c652a.jpg

Not about more articulation or anything, but the angles of your short/mid arms are just getting extreme. Others might have differing opinions about where the optimal threshold is that you go to long arms. IDK. I honestly can't imagine more than the 3.5" lift I have.....it's pretty aggressive to me.

One thing to keep in mind is higher is not necessarily better. You need some lift to fit the bigger tires, but you can fit 40s on 3.5". the higher you go, the higher that center of gravity is, and the quicker you feel pretty tippy when you're getting off camber.

Long arm kits really all have their own issues. Nobody makes a great out of the box solution, and you start getting more in to custom stuff.....not to mention you're not improving your articulation any....they're just helping with the high lift height some apparently want. I would never tell you to go long arm kit myself.....and I wouldn't say run out and swap your springs for something lower......just some food for thought is all.

I intially wanted a max net of 4" and now Im stuck at 4.75" and Ive been correcting for it accordingly and probably looking back I should have just gotten a 3.5" spring and not a 4" spring. Flipping the drag link tomorrow and reloacting track bars front and rear. It does drive really stable good now ...im running no stabilizer. Hopefully, it'll be ready for my fire road pipeline running, I am an inspector on the pipeline, need it to be as durable as possible with my weak D30.

Can I run the control arms in the geometry correction brackets to maintain a minimal angle on the arms? Or is this just defeating the purpose of adj. control arms?

4.75" of lift? What size tires are you running? Geo correction brackets are better if you can stand the loss of ground clearance. If you run the adjustable arms at the same length as stock then you should be fine running both but, yes you didn't need to buy adjustable arms if you are using brackets.

These springs gave me almost an extra inch. They are 4" ICON springs. Running 35's I purchased the adjustable to replace these worn stock ones and just wanted better. I'd like to lose the brackets but not if it will be detrimental to ride. I was thinking just get some MC 3.5" springs and lose the geo brackets and use the adj. properly.

Depending on the weight, you may not be losing much height with those. Have you considered the 2.5"? Should be plenty for your 35's, especially if you are running flats.

I have a set of 2.5" MC springs sitting in my garage, boxed up and ready to go....under 10k miles on em. They're listed in the "Marketplace" if you care.

As you see, a lot of springs will net you more than the stated number, especially on a lighter jeep if you're not weight down by heavy bumpers, armor, winch, etc. IDK, it's personal opinion, but that's a lotta lift for 35s. If it works for you and you like the looks, doesn't matter what anyone else things. IMO, 2.5" for 35s, 3.5": for 37s, and no reason to get crazy going higher. Even at solid 3.5" net lift, I think I have a lot of open space with my 37s, but that is probably exaggerated since I don't have fender flares.

If your old arms are not in terrible shape, and you're ok with the loss of ground clearance, the geo brackets are and factory arms are going to produce a better ride. It sounds like for your use though, which is not aggressive off roading, you would be fine throwing those arms on and ditching the brackets.

This discussion reminds me of the recent lift kit vs. Franken lift approach discussion. This seems like a Franken lift scenario approach where unless you really understand the complete geometry of the suspension, then going with a Franken lift approach may not be the best idea for the average joe.

So the OP is starting with springs that are at a height that requires either arm replacements or geo brackets but the height of the springs are in an area where there is a lot of uncertainty of where to start with those arm lengths, where it seems the best approach would be to start with the MC recommended lengths since MC has done that geometry engineering work but then the question comes into play of how much different are the heights of the MC springs from the Icon springs once installed? So the solution to that question is to move to the MC 3.5" springs, so we can feel more certain about the length of the arms. Do I have this summarized pretty well?

Sounds like a fun project trying to figure that all out and dial it in, if you're a suspension engineer. :D

When I look at this situation where the original goal was to get 4inches of lift and mount 35s I would have taken a totally different approach of either saving up my duckets for a 3.5" MC Game changer lift or if I wanted to pay less for a good value lift, then go with the Mopar 4in lift and add some Franken lift components to it at a later time as needed.

You are not going to know until the coils are installed and settled in. Personally moving to 3.5" MC coils is a bad move and he will likely be in the same place or close to it. If a coil swap is done I would go with the 2.5 which will likely net 3"+ of actual lift since he is just running 35's. Even at 3" some corrective measures should be taken for axle placement. On adjustable short arms you are really not dealing with geometry since you are not moving any brackets. you are dealing with restoring caster and adjusting pinion angles and correcting axle shift.

That would be the correct thing to do.

However, to be PC we should be polite and ask the reasons the original goal was to target for 4inches of lift, while planning to mount 35s? I've found there are typically 3 reasons. ;)
1. Looks (They like that look of the high rise although most of us know it doesn't provide any benefit while increasing the costs for correction).
2. Longer term plan (Considering leaving their options open to be able to mount 37s or larger tires in the future).
3. Additional belly clearance (Which is the typical answer from someone that lacks the understanding that their axles and other components are still hanging down and reducing clearance).

I will give you a 4th reason, ignorance. Not understanding the JK is factory set up for big tires and offer the room to go 35's with little effort compared to older jeeps. The older models came with 28"-30" tires and took a lot of lift to run a 35" tire. People equate a jeep on 35's need 4" of lift. The JK comes with 32" tires and making theme to 35's is rather trivial. To make the same comparison you would be looking at increasing tire size by 5"-7" on a JK and running a 37-39" tire on 4" of lift. Unfortianally with he larger tire size on the JK and moving up to such a large tire creates other issues like axle strength and lack of power from the factory motor to push that big rubber moving the real expensive from the lift to the other things needed to handle such big tires.

Just to add a visual, this is MC 3.5 and 37" stt pro's, before I got around chopping this set of stock fenders. I keep thinking about dropping to their 2.5"...

https://cimg4.ibsrv.net/gimg/www.jk-...9fc18cd13e.jpg

No real reason for 4" just seemed moderate to me. Meh...It's whatever. Thanks to you guys, it's sorted out now (flipped DL, relocated TBs) and just kept the geo. brackets and stock arms. Just returning the control arms. Thanks for the replies.

For the record, I only suggested the MC lengths as a starting point as 1) I knew they provided the lengths in the instructions, and 2) I figured that MC springs would net him more than 3.5” if he had those…getting him close to the lift he currently has, so the measurements would be a good starting point. I also noted this wasn’t an exact science, and would be a little trial and error getting it dialed in. Those starting lengths would be better than a willy nilly random starting point. Not that MC has the whole geometry thing figured out….could have given links to any other manufacturer….lengths would all generally be about the same starting point...and there's a wide range of acceptable length combinations netting a range of caster that would have worked.

I hope you didn't think I was criticizing your advise, because I really thought it was great advise and would have been exactly the approach I would have taken given the situation. I was being more dismissive of getting into this situation to begin with sounded like something that could have been avoided with a little more planning.

Ok...I returned the fronts and buying MC rear CAs, calling it good on the suspension for a while. Yes I was a little hasty in my purchases. Its all better now so...