A little Ford history lesson from someone who was there...The Gen 2 rear suspension was amazing. Full aluminum double wishbone with toe links and anti-sway bar, allowed an adult size 3rd row with fold flat seats...and it handled much better than it's size would indicate. You could actually turn off the 4x4 and with a limited slip rear end you could do donuts in the parking lot without that special "about to tip over" feeling. The 4 wheel air ride only improved it.
But, the new Product Development VP at Ford, Phil Martens, was not a happy camper, he thought the IRS on both the Explorer and Expedition was a waste of money and wanted to undo it and go back to SRA on both of them. It was difficult to make him understand that in both cases it was all about superior interior package which was selling and hurting GM. In the end there was a compromise that pleased no one. The Gen 3 "multi-link" was hastily developed and launched. It was more expensive than the Aluminum Double wishbone with more unsprung weight, more variability, more attachments...and worst of all, it wallowed like a pig. But, it preserved the interior package; and, Phil was satiated because it was no longer a "race car like" Double wishbone. I was leasing a 2006 KR and a 2007 Limited at the same time for several months. My wife and I would do rock, paper, scissors to see who got to drive the 2006 every morning because we hated with the way the 2007 wallowed. The suspension is the same in the gen 4's as the gen 3's. I'm curious to hear from anyone on how the aftermarket anti-sway bars work. They look solid enough to restrict some of the link and bushing compliance which is the real problem, assuming that the bushings on the sway bar are sufficiently stiff. There are just too many links with too many bushings to keep the knuckles properly located. The stiffer gen 4 springs don't really help much because there is enough compliance in the bushings to sway the truck without compressing the springs.
