My last comment would be driveshaft. I have had the OEM balancing weights fly off my DS in older trucks with high miles, but it can happen at any time.
Have a reputable driveshaft specialist take it out and check it for balance and trueness, especially if you have ever hit anything or been off road much...
Have a reputable driveshaft specialist take it out and check it for balance and trueness, especially if you have ever hit anything or been off road much...