I recently purchased a 2015 JKU that the previous owner had installed a TeraFlex Budget Boost on. The local Jeep specialty shop just installed a raised rear track bar bracket and we started talking about other future projects. He is suggesting that I replace the control arms with adjustable arms, and is going to give a good price on Rock Krawlers (appx 15% off what Northridge has them for), and can install them. I'm hoping this will increase the ride quality.

Is there something that should be done before the control arms, or at the same time? I was thinking of having all of them replaced, but he also mentioned just doing the fronts and maybe replacing the springs. I'm happy with the height, but I'm mainly concerned with ride quality and durability. This is my daily driver and doesn't see much hard offroad use, just orange groves and cow pastures.

Any thoughts or suggestions?

 

Personally I think for a budget boost I would skip the control arms as should not be necessary. I would go with some better shocks if it were me giving advice

 

The shocks were replaced with teraflex vss 9550's when the lift was installed.

 

For your intended use, there is nothing at all wrong with a budget boost. Assuming you don't find yourself adding a bunch of weight, no need to swap coils. (unless you just feel like throwing a bunch of money at your new toy...)

As the lift height increases, the caster decreases, causing progressively flightier steering - the higher you lift, the worse it gets. At 2.5", many don't bother to fix it. If you choose to adjust the caster, a single set of arms up front is all you need. Lowers are generally preferred, but uppers will work also. (again, unless you just feel like throwing a bunch of money at your new toy, no need for the other three sets of arms at that height...) You could also look at a set of control arm brackets instead of new arms. (AEV, Rancho, whoever else)

Also be aware that many aftermarket components have greaseable joints. Might be something to consider if you aren't good about doing extra maintenance (with a full set of arms, could be 16 more spots to grease every time you change the oil...) I believe RK has gone through several versions of joints, so wouldn't hurt to ask which ones are on the arms your shop is suggesting. And if you want other suggestions, look at MetalCloak and Synergy.

 

My caster is low, 3.6 deg, and I have a smittybilt xrc from and rest bumper, winch, 33" spare on a moryde hd carrier. I think the rear sits a little low.

But, fronts control arms are all that's needed? Why not rears too?

If I swapped out the coils, to a 2.5" front and rear, would that be better than the stock coils with spacers?

 

There is no caster in the rear, pinion angle is the only consideration. And it is not an issue on a 4door at that height. A second set of arms at either end would allow you to fine tune the caster/pinion, and also allows you to move the entire axle forward/backward in the wheel well. This gets more important with taller lifts that reduce the wheelbase, not so much at 2.5".

If you have enough weight (coil sag) that the stock coils are compressed to where the bumpstops are contacting, sure, going to coils designed to handle the weight could be a good choice. Just be aware that many coils give quite a bit more lift height than you might expect, so do a little research on whatever company you choose. You could end up spending a LOT more money if you end up at 4" instead of the 2.5" you are shooting for...

 

Is there a source of info on which coils give more or less lift (chart, manufacturer, etc) or just search for user experiences here on the board?

Also, if I changed out coils and ended up with 3 or 3.5" instead of 2.5", what problems am I looking at fixing?

 

most companies base their lift height on jeeps with steel bumpers and skid plates etc. so if putting any 2.5" coil lift on a light rig you will probably get 3-3.5" of lift. that of course effects driveshaft angle and on 12 and up rigs can mean if you run stock driveshaft up front you will need to add an exhaust spacers otherwise when fully drooped up front your driveshaft boot will contact the crossover on the exhaust.

If you looking for smoothest ride I still would not go with rk control arms as they won't be as smooth as say a teraflex sport or alpine lower control arm due to the fact that the teraflex sport or alpine arms use stock clevite joints ie rubber vs steel. If you are certain you want new arms get something with a rubber joint. also at your lift the sport arms would be cheapest and increase your caster to a suitable level on a 2-3" lift. For what you describe your usage you would actually be better served by geo brackets ie aev or rancho to name a few as they will actually improve on road comfort as they put your control arms more level so the minor impacts are softened on road. They are also much cheaper than control arms at around $105 for the set. Better shocks would still be on my list if I were in your position. If you are happy with your lift height now get some TF performace 1.5" coils or Rockkrawler 1.5" triple rate coils. combine the geo brackets with these coils and you probably not going to spend much more than what you can get the rk control arms for.