05 2500 I have a vibration that feels like a bad u joint less noticable at highway speeds. I have checked all u joints every thing is tight, it does go away when throttle is closed. fluids are good in all diffs and transfer case. any ideas where to start to look next?

 

Even if they are light they could be rusty and cause a vibration. See if you can see any rust around the grease boots.

 

Carrier bearing.

 

carrier bearing where?

 

Gear box stabilizer?

 

its not in the steering

 

Mid-Shaft bearing.

 

It separates the 2 halves of the rear driveshaft.