Air Bag and Overload Spring Question
Sorry, I know this has been debated, but even after reading the archives and elsewhere on Google, I don't have a full understanding. I have a F350 with AirLift 5000 air bags that I installed in the rear since my last trip. The two bags together are rated at 5000 pounds carrying capacity, at 100 psi. Let's assume my camper weighs 2500 lbs. If I have 50 psi in the bags, then the bags should be carrying the whole camper load and the factory springs carry the empty weight of the truck bed, etc....and the overload springs would not engage, as there is ~2" clearance from the bump stop. In fact, in real life at 50 psi, I'm still tail-high, but not as high as unloaded...I have to get to almost 100 psi to have the same clearance. 50 psi gives me ~1" (although higher at front stop than rear stop).
So I suppose my real question is, when a truck has a heavy load such as a camper, when should the overload springs engage the bump stops? It appears the Torklift Stableloads are designed to force the springs up toward the bump stop, and other approaches have lengthened the bump stops to allow the springs to engage while running at higher air bag pressure, yet avoiding sway. I've seen some say that the springs should just touch the stops, but I can get that at only 25 psi...and at 25 psi, the bags would only carry 1/2 the weight of the camper. I did not install the on-board compressor, so trial-and-error takes some time, and I guess provides the real proof of the pudding. But I was hoping somebody could help me think about this topic correctly, and provide a reason for the clearance from the bump stop. Note: I generally only run in the daylight hours, so I am not overly concerned about headlight aim.
So I suppose my real question is, when a truck has a heavy load such as a camper, when should the overload springs engage the bump stops? It appears the Torklift Stableloads are designed to force the springs up toward the bump stop, and other approaches have lengthened the bump stops to allow the springs to engage while running at higher air bag pressure, yet avoiding sway. I've seen some say that the springs should just touch the stops, but I can get that at only 25 psi...and at 25 psi, the bags would only carry 1/2 the weight of the camper. I did not install the on-board compressor, so trial-and-error takes some time, and I guess provides the real proof of the pudding. But I was hoping somebody could help me think about this topic correctly, and provide a reason for the clearance from the bump stop. Note: I generally only run in the daylight hours, so I am not overly concerned about headlight aim.
