I have been posting on another thread about my towing problems with the 3.31 rear gears and the undersized sway bar. I got my 2008 Expy back yesterday from the dealer after the gear swap and the sway bar change. There was a small problem on the sway bar, it seems it was not designed to work with the air suspension. My dealer got creative and found one for the Navigator that had the same diameter and ratings. I immediately noticed the better performance even without the trailer. But with the trailer and the hitch setup...WOW! I can accellerate onto the Interstate easily and even in a light breeze almost "ZERO" sway. We topped off the tank and according to the mileage monitor I gained 4 mpg under load! It was consistant at 12 mpg with the trailer and then topped off again and 18.3 at 70mph on cruise. Ford needs to go back to the pre-2008 HD tow setup because it works.
Okay, 678 mile trip with the trailer. Average mpg WITH THE TRAILER ATTACHED was 13.1 for the trip. I tried to hold the mph around 65 mph. NO SWAY in fact the driveablility is better with the trailer. I have developed a strange noise under the rear seat that sounds like metal against metal when turning? I think it is the load leveler bars bars but I can't figure out why it sounds like it's under the rear seat.
Semper, Ford paid the whole tab under a customer consideration policy. The actual cost on the warranty claim showed $1173. You could probably get this done at an independent shop for $800 including the sway bar replacement. A guy I talked to at the campground Saturday told me the big difference on the sway bar is that the stock one is tubing and the Navigator is solid. He works at the Ford dealer in Texarkana and said they have done that swap before as a customer pay but not under warranty.