Hi, Socal77:
When I first looked at the leaf springs on my unit (also a 28A former CA rental) I noticed that Leaf Springs sagged down or bowed down especially at the ends that point towards the engine. I thought this was unusual until I did further research. It turns out that this is normal for most RV's. Ford basically makes the chassis and then they basically don't care whats done afterwords by the Thor Motor Home company. The Ford OEM chassis can only handle so much of a load in the rear so when a huge box gets built on top of it, the springs will bow down. If both Sides of the Leaf Springs bow down evenly, then you will not notice a lean towards one side or another. But you will notice a harsher ride at the rear. As the OEM Leaf Springs just will not lift the Box enough to be able to provide for a more comfortable ride. When there is more weight on one side than the other then, over time, one set of springs will start to sag or bow-down more than the other and there, RV looks like its leaning.
What most have done is Not to replace the OEM leaf springs (Huge Job) but to add a "Lift-Support" system that will assist the Existing Leaf-Springs. This is what I am planning to do with mine. For now I have upgraded shocks (Bilsteins on all 4 sides and added Hellwig sway bars on front and back) to improve the ride. Here's a few pics of what I'm talking about. These items are on the SDTrucksprings website. Hopefully this helps. The pics are 2 options, one is adding an additional Lift Spring and the second option is to add an Air-Lift system. I prefer 2nd option (easier to do).
