Here goes. I have an 03 F250 with a 7.3l and a 4r100. The truck also has a what I think is a 4" lift with 35" tires that had been installed prior to my purchasing the truck. When I start foward motion from a dead stop I encounter a noticable shimmy (shake). I initially thought this was axle wrap, that the pinion angle was just going way skyward and causing the driveshaft to vibrate due to the universal being stuck in a tight angle. But the more I drive the truck the more I think it is from something else b/c I also have started noticing it when I let off the gas while applying no brakes. The shimmy is also strangely not as apparent when under hard acceleration from a dead stop. What could be causing this? Could it be the tourqe converter? The tranny itself shifts nice and firm with no noticable slipping and my tranny temp guage is cool, normally less than 150 degrees.