I've experienced this same shudder. It doesn't seem to be axle wrap as others are describing. Our issue seems to be tied into the transmission. Did you ever get any resolution tho this issue?I have a 2009 F-450 4x4 with 22,000 miles on it completely stock (except for the Banks DPF back “monster” exhaust and Banks cold air intake). Last night as I was driving on the highway for about 40 minutes doing 55 MPH when I punched the accelerator to pass a vehicle and the truck began to shutter, the tachometer was at 3000 RPMs and the truck didn’t gain any speed. I immediately let off the accelerator and the shutter went away. A few hours later, I was again traveling on the highway doing about 50 MPH and punched the accelerator to pass a vehicle and again the truck began to shutter, the tachometer was at 3000 RPMs and the truck didn’t gain any speed. I didn’t let off the accelerator this time and the truck continued to shutter for about 15 seconds before the RPMs dropped to about 2000 and the shutter went away and the truck picked up speed. Just after that, going up a bridge doing about 55 MPH, I punched the accelerator but this time the transmission didn’t downshift but the turbo boost gauge pegged out and the truck very slowly gained only 5 MPH after about 20 seconds. I was able to replicate the shutter issue this morning on my way to work under hard acceleration from a stop. I think this is a transmission issue but any help with this would be appreciated.