So my truck has this annoying vibration. It has done it since new. Now has 11k miles. I am finally going to break down and take it in for warranty repair. I want to go in armed with as much information as humanly possible so I don't waste unnecessary time on the "cant replicate problem" or "its a normal characteristic" B.S.

It only does it when you are travelling at 40-55 mph and you simply let off of the gas and coast. Its noticeable to everyone in the truck, driving or not. It goes away if you accelerate at all. It goes away if you get on the brakes moderately hard. It goes away if you get outside of the 40-55 mpg range.
It does not matter if you are hauling a trailer or not. It does not matter if you have a load in the bed or not.

Truck is 100% bone stock. 17" Factory Goodyear tires are all inflated to 40 psi.
2015 xlt 4x4 supercrew 6.5 bed 3.5 ECO. Has the 2 piece steel driveshaft. Has the Ford 9.75" rear end. 3.55 gear ratio.

I suspect the problem is in the drive line, maybe pinion angle?

Anyone else have a truck doing the same thing? What say you?

 

Its probably the 2 pc driveshaft that comes on the supercrew with the 6.5' beds.

 

I had a '13 and a '14 regular cab and believe it or not, they BOTH had the two piece driveshaft, and they both exhibited the same vibration. Mine was always at 55mph.

 

ah crap

 

I wonder if they would be able to re balance it?

 

I have a 2015 XLT 2x4 with about same mileage as yours, I've been experiencing the same problem at the same speed and it goes away doing the same you do to get rid of it, next time I'll take it for service I'll see if they can do something about it...

 

Sounds like we are having the same problem. 2700 miles.

https://www.f150forum.com/f118/vibra...65-mph-345095/