Hi,
I have Airlift 1000s and aftermarket airshocks installed on my 2005 PF. The rear tires are wearing along the inside edge with less wear gradually towards the centerline. Outside edge is normal wear. To me this indicates a kind of sagging. But looking at the level of the PF from the side the rear does not appear to be any lower than the front. I'm wondering if I need to increase the air in my shocks or decrease them to achieve normal tire wear. Normally, I don't have a load but when I do I have one (sometimes two) dirt bikes that "hang" off the hitch on a motorcycle carrier. This happens on every 3rd or 4th weekend for a total of 4 hours. This just makes me want to get an Expedition with the auto-load leveling air shocks.