I wonder if this buffeting issue is some kind of artifact of the truck riding on essentially an ancient frame technology. The rear axles on these are essentially the same design as they were in the 80s. They don't break, though.
Not making any claims, as I have no data at all - so nobody flame me to death. I will set forth a hypothesis that the people who are noticing the "buffeting" are people who have not driven this kind of car much in the past.
I saw my share of rear ends break in F-bodies (4th gen Firebirds/Camaros), but mostly with those running big power or sticky tires. The Ford 9" was known to be nearly indestructible.
One significant change that is worth noting, apparently, "American Axle Manufacturing" who makes our axles, recently moved their operations to Mexico and touts a new machine which can machine our ring/pinion in 2 cuts instead of 5. I'll never know if this is why I had vibrations. I do know that a complete axle replacement eliminated my vibrations.
The buffeting is not normal body-on-frame noise. The previous generations did not have it, nor does the competition, at least the ones that I drove or have been a passenger in. All this "Shakerado" and bufetting talk really only got steam with the new K2XX platform which started in 2014 for the pickups and 2015 for the SUVs.
I do agree that one shouldn't expect car like sound levels in a truck, but now that my wheels are balanced, it's pretty damn quiet at any speed!
