Nope. This is a very common misconception. Struts and shock absorbers do not set the height of the vehicle. Shock absorbers only reduce its tendency to bounce like a basketball. Struts do the same but they also hold the spindle / wheel straight up and down, so they're much stronger. They're actually a necessary part of the suspension system, when used. Shock absorbers are not. In fact, since I refuse to give up my rusty trusty '88 Grand Caravan, and I live in Wisconsin, the road salt capital of the world, my right rear shock absorber rusted off two years ago and isn't even there. I don't even notice it. The ride quality is fine.
It's the springs that set the ride height. There's two things that confuse the issue. The first thing is most struts and shock absorbers today are gas-charged. The gas pressure simply reduces the oil's tendency to become aerated and lose its effectiveness on long trips. But it's also that pressure that makes the shaft extend on its own when the shipping strap is cut off. You can push that shaft back down by hand, so obviously it isn't putting enough force on the suspension system to raise the vehicle.
The second point of confusion is many shock absorbers and struts have a helper air spring built into them. That is actually not part of the ride-dampening shock absorber. It is a real helper spring that just happens to be built as part of the shock absorber. They are not strong enough to hold up the vehicle on their own. They are adjustable and just assist the main springs.
GM has been very good at hooking people with very expensive repair parts and procedures. The aftermarket industry takes advantage of that to develop high-demand parts at a much lower cost. Start by looking at local auto parts stores, or online at Rock Auto.
Next, consider having the air shocks removed and new coil springs installed. This is commonly done on Ford products. Ford does a real poor job of supporting their products when they get to be four or five years old. A lot of larger cars were not available with anything other than air bag suspensions, and when they pop leaks, there was no repair available until aftermarket companies started offering retrofit kits. The complicated and trouble-prone systems are discarded, and new coil springs are installed. The ride quality stays the same. The only thing owners notice is the vehicle is back at its proper ride height.
Replacing rear coil springs is not very involved, and there are some that provide increased height when heavy loads are always on board. It's very important to maintain the designed ride height for proper handling, braking, steering response, and tire wear. Switching to the stronger springs will achieve that when the van is always heavily-loaded.
Thursday, November 28th, 2013 AT 8:28 PM