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.