I think I answered my own question by taking and posting this photo. Note how the red airbag tends to skew the right rear spring a bit. This makes the spring strike that horizontal bar doohickey, making a loud clang.

My air bags are essential - When they're deflated, the tires rub. But when they're inflated, this happens. Any suggestions?

 

How much lift are you running? Is your axle centered (front to back) in the wheel well? If not perhaps adjustable control arms will unskew your springs...

 

The lift is the Full Traction 3" Ultimate, installed by Off Road Evolution. I am a perpetual n00b and don't know if that involved centering the axle; nothing was done beyond the kit installation.

 

I got the same thing with my 4" LA LCG lift. Talked and showed pics to Joe from TeraFlex and they recomended 2 solutions.
1. Get the 10 degree wedge that Rockcrawler makes.
2. Get the KMA spring pearch and relocate the spring locations.

I did the wedge and have been pretty happy with the axel wrap eliminated.

 

Can you give me more info about that 10 degree wedge? I tried a web search and couldn't find anything like that.

 

Rock Krawler personnel are available from 10 A.M. to 6 P.M. E.S.T Monday thru Friday and can be reached at 518-270-9822

Call them its like 25 bucks

 

have a good look at the picture, the bushing between the bag and the spring saddle isn't sitting right. looks like its pushing the spring in that direction

 

Thats just a bushing for the air bag. I have my springs held down with a large washer and bolt. This is a common problem on the rear axel. The spring is sitting on its perch

 

X2 on what W&W said. I have a 3" lift and my D side spring was hitting on the trackbar. $25 for some spring wedges fix it right up. The springs aren't perficatlly vertical, there is still a slight bow, but it doesn't hit anymore. Also my springs are new and I'm sure once I get a new bumper/tirecarrier, things will settle down and the spring will straighten out.

 

Had the same thing happen with mine. The cause is you rotated your axel to get the correct pinion angle and now your spring perch is too far back causing the spring to look like a bananna. To fix mine I bought upper control arms and re-centered the axel in the wheel well then I had the factory spring perch cut off and welded new perches on the top center of the axel. You will be surprised how that bend is also effecting your ride. Once it is fixed and the spring is straight up and down as designed your jeep will ride completely different. Good luck