I’ve been experiencing a rumble on and off. Similar to an unbalanced wheel on the highway or a rumble strip. But at speeds between 25-45 is when I notice it most.
This morning, I felt the rumble worse than ever with a faint squeak. At 40mph. I can’t tell what direction either of them are coming from, and I can’t think of something to relate the squeak to.

It starts randomly and does not go away regardless of slowing down or speeding up or stop and go will not reset it. But will eventually go away on its own.

-It changes with speed.
-I know it’s not engine related, I actually shut the engine off in neutral at 40mph, still there.
-It doesn’t seem to be a wheel balance issue, the rumble frequency is too fast for the speed.
-I don’t believe this is related to the IWE issues, and makes no difference in 4x4.
-seems to be driveline, possibly driveshaft?

2010 super crew 6.5’ bed 5.4L

 

I'd suspect u-joints.