Firestone Airbag Install on Lifted JK
 

I have a 07 4dr JK with a 3.5 lift and 37 toyos, after adding Smittybilt rear Atlas bumper with tire carrier and 2 full jerry cans, warn recovery kit, Hi-Lift Jack, chains, straps, and subwoofer box with 2 15s in it, my Jk was rubbing the rear inner fenders even with a Bushwacker flat fender kit. Not to mention the extreme body roll in curves do to the added weight, and forget about hooking a trailer up to it. I knew what I needed but nobody makes a airbag kit for a lifted JK. So I called Firestone and after talking with them and measuring my coils they found that Firestone Kit 4151 for a Mercury car had the bags I needed along with all the connectors and hose. I ordered the kit from sdtrucksprings.com for 94.00 shipped and in 2 days I had it. I used the Hi-Lift jack to raise the JK and completely decompress the springs one at a time and in 2 hours I was done. I put 60 PSI of air in each bag and that raised the completely loaded Jk to 1/2in over what it was empty. I took it out for a test drive down a rough road that bottomed my JK out empty much less full and I had zero rubbing, not once, the body roll was gone and it drove as if it were a stock jeep with nothing in it. I could probably lower the air to 45PSI in each bag and be fine, but I like the firm ride at 60PSI. And if I hook my trailer up to it all I have to do is increase my bag pressure to level it back out. Im very impressed with the kit and the quality of the air bags.
I wanted to post this in case anyone else was experiencing the same issue I was after adding weight to the rear. Hopefully this will save you some research time and help you as it did me.

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I installed the airlift 1000s on my rig. I get the exact same results. Now my rig is built as light as I can. I kept the stock bumpers and modified them. I installed them for when we load the Jeep, or tow our various trailers. But I did get an 1/2" raise in height just installing them as well. Airlift and firestone pretty well can match your springs to a bag in their system. I am getting 3 more sets, for my mazda 5, avalanche and suburban. They are just to good not to have in the rigs.

What suspension are you running? Just curious because I know springs have a lot to do with it. I originally had rough country and after a few months towing my work trailer it sagged badly. I know they weren't made for that but it still sucked. I picked up some slightly used AEV springs and it's night and day difference. I still want to get air bags and larger rear sway bar so I can tow a camper.

I'm running a rough country 3.5 in suspension, and your right, I could have went with stiffer springs, called rough country and they were gonna send me a set to cure the problem, but when I unload all that stuff my ass end would be damn high! So I wanted more control of my ride height and this really solved all my issues.

Thanks for posting this. My ass end on my RK 3.5" kit is 1" lower than my front when measured from the Rock Rails. I will be installing Teraflex 1" spring spacers, but now I'm also going to look into this for when I'm loaded down. How well are they holding air?

I just checked the pressure on both bags with my digital guage, they both still had 60 psi in them after 3 days now. It uses 1/4 quick connectors and 1/4 airline. I already have 3 1/4 but splices in the toolkit in the back incase of a issue. I pounded the hell out of them Sunday right until my alternator decided to have meltdown with no issues of rubbing the pinch seam whatsoever. They have exceeded my expectations. Right now I'm awaiting delivery of my 320amp alternator from Quality Power out of Cali which will be another post.

That's another thread I'm interested in. I'm still fine tuning my suspension, but my next step is electronics. Stereo, switch panels, alternator, duel battery, etc.

Do you by chance have an up close picture of the air bag in the spring? Just curious what is used at the top and bottom of the spring. I have teraflex 1" spacers which have a cone on them to keep the spring from falling out during articulation. Would this be in the way? Seems like it would be easy enough to cut it off.

I asked Firestone about that upper cone that protrudes downward about a 1/2 that's made of rubber, the said it would be fine and not cause any issues and that the included 1/2 spacer with a hole in the middle for the airline to go thru was for protection of the fitting on the bottom of the airbag. But if the Teraflex cone is a hard plastic unlike the factory rubber one, I would smooth it out. The bags are flat on both ends and are a very thick durable plastic. Something bad would have to happen to damage one after examining how well their made.

Ok, thank you.