Inconsistent whine noise occurs at various speeds - 2006 6.6L - Hello, My 2006 Silverado with 70K miles (2500 HD, 6.6L, 4x4, auto, crew cab, 8' bed) has been making ...

Hello,
My 2006 Silverado with 70K miles (2500 HD, 6.6L, 4x4, auto, crew cab, 8' bed) has been making an inconsistent whining noise for the last couple of years and has got progressively worse recently. I'm hoping someone may have some ideas what the sound could be and how to fix. I've taken to a couple of different repair shops, but they were unable to identify what the issue is. Next stop is dealer, but thought I'd try the forum first... Following are some additional detail on the inconsistency of the whining noise.

When I purchased two years ago I would hear the whining only when the rv/camper was on the truck -- would hear it at very low speeds (maneuvering into camp spots, parking lots etc), as well as inconsistently at higher speeds.
Within just the last four months the noise is occurring much more consistently (daily) once the truck is WARMED up, and NEVER happens when cold. It seems to occur more often when UNDERWAY around 1500 RPM or when ROLLING to a stop (foot off accelerator), or ACCELERATING from a stop. TURNING and BUMPS also seem to trigger the whine noise.

It's difficult to tell exactly where the noise is coming from so tried to capture on VIDEO it (passenger was recording) - hopefully quality is good enough to give you an idea what I'm hearing. In the video I'm traveling between 20 and 25 MPH. http://youtu.be/r5vfqLnXrvc

THANK YOU in advance for any insight or guidance you can provide!

Wouldnt let me watch the vid?

Does it take you to YouTube? I just clicked on link in post and it took me right to it. Here's another version of the link that will hopefully work better for you...let me know.
http://www.youtube.com/watch?v=r5vfqLnX ... e=youtu.be

Hm, ima have to try in on the comp, my phone freakin out i think Idk why

Edit: reboot fixed it

That sounded more like a squeel than a whine to me. It was too hard to tell from the video where it was coming from. Can you give me a better idea of where it is coming from on the truck? It kinda sounds like an A/C compressor clutch slipping.

Jordan, if so, could he turn off the ac and see if the noise dissipates?(big word)

It depends. If the bearing in the clutch is worn out and it is causing the pulley to move (tilt off it's axis) a bit and contact the clutch face, it would be making the noise with the clutch in the "off" position. If it was a problem of too much space between the pulley and the clutch face to allow for a good lock between the two (it is an electro magnet) then the noise would go away when the clutch was in the "off" position. I have heard this noise (like it sounds in the video) most when water is sprayed on the clutch while it is in the "off" position and the clutch is turned on before the water dissapates (I thought I'd work a big word in as well). Usually when this occurs the noise goes away in a second or two when the clutch dries enough for a good hold.

Does this motor have separate ac belt like the 5.3? If so maybe slip the belt off the ac to help eliminate or verify it..

I'm not sure. You could do that if it did though.

Thanks for input. "Squeel" is probably a better word to describe noise. Seems sound is most likely coming from front (engine or wheels) or center ( tranny / driveline).

A/C is never on when squeel occurs. I live in seattle so a/c is rarely used.