Just got my Screw 4 x2 back and my vibe is gone. They replaced the Ring and Pinion inside the rear-end or "hoghead" The service tech said the prelaod and backlash were "set incorrect" It seems like a totally different truck.

I was able to get in touch with an engineer at the Ford plant. His thouhgt on the vibe was it was due to a bad drive shaft. On certain models they have gone from a one piece to a two piece. My service manager says that is not the reason at all, and have now sucessfully treated 3 trucks, including mine with the ring and pinion replacement.

I think I might go back to the dealer who put that "jerry rig" damper kit on and said my truck was normal and give them a yard job.

I hope this info can help some others with the "affliction"

 

I think there are tww issues.

one vibration is drive line related, or speed related. that was the root issue with your truck and the rear end gears were fixed. the other is the NVH (noise, vibration , and harshness, an auto industry term) of the vehicle. A frame and body natural frequency issues. i experience this NVH issue with my truck but no driveline vibration. the damper is used to help solve the NVH issue.

so they did not understand or witness your issue themselves, or were just clueless. the damper is still a potential fix for a different issues..
just my opinion

Ramb

 

I'm sure the damper kit does fix some vibe problems but it will always seem as a "jerry rigged" solution to me. At least it was bolted on and not duct taped.

I was more annoyed that the one dealer blew off my problem as being "normal" I know I did not buy the truck from them, but they can bill Ford for warranty work too.