Before
After
We really like the idea of airbag suspension: a system where you could lower or raise your ride at the push of a button, squat the rear end or raise it up, or even pump up one side to keep the 4x4 more level during off-camber situations (with the right controller of course). You've probably heard all these pros of airbags before. But we don't like the fact that you are pretty much screwed if you pop an airbag out on the trail and don't have an extra one. Even if you do carry an extra one, have fun putting it in on the trail.
We came across Universal Air's air-assisted coilovers that let you raise or lower the vehicle 5 1/2 inches. It was like someone was actually listening to us when we described just what we wanted in a spring piece. They sell the bag by itself, the bag already mounted on a coilover, or a complete system with a full air-management kit included. Check it out.
Here's Universal Air's setup at fully deflated (A) and fully inflated (B). The bags go from a height of 4.00 inches (compressed) to 9.25 inches (extended) and offer 5 1/2 inches of forced articulation... | 
...They have a 0- to 3,000-pound spring rate on the 2.0 coilover versions (shown here), and will have 2.5 coilover kits by the time you read this. | 
The beauty of Universal Air's kit is that it is a totally self-contained unit with an internal chamber that does not seal against the shaft or body of the shock, so there is little chance for any leakage. They work the same as conventional airbags, but have an inner collar that slides onto a coilover shock body. |
A fully assembled and installed bag on a coilover shock looks simple. The inner and outer walls of the airbag are clamped together and seated between steel ends. | 
There are two flat plates that retain the bag setup and hold it in position above the coil spring on the coilover shock. The top is drilled for the air fitting. | |