High-pitched noise when accelerating/decelerating at low RPMs (2024 Silverado 2500)

[switters]

Hi all, I just bought a 2024 Silverado 2500 6.6 Allison gas with 11,000 miles. It's making a strange, high-pitched whining sound at lower RPMs when accelerating/decelerating. It's hard to explain, but my wife and my friend immediately noticed it when they got in the truck. I made an audio recording, which you can listen to here. Unfortunately, the sound is way less clear on the recording than it is in person, but you can hear it, especially between 3-5 seconds. I'm going to take it in to the dealer, of course, but I thought I'd post here to see if anyone has ideas of what might be causing it. Thanks. 

Edited August 25, 2024 by Chris Kresser

[BuckWallace]

Is it similar to this?

 

 

Edited August 25, 2024 by BuckWallace

[switters]

Thanks, Buck. It's hard to tell with the recordings. I'd say mine sounds different (more noticeable), but I can't be sure. 

 

What I can say is that I went to a Chevy dealer yesterday and drove both a 2500 and 3500 with the gas Allison transmission. Neither sounded like my truck. They were both relatively quiet (for 3/4 and 1 ton trucks, at least) and smooth. This tells me it's not normal. 

 

 

[BuckWallace]

Yeah, it's hard to tell from the clip but it does seem a bit more high-pitched. Let us know what you figure out at the dealer.

[Tuishimi]

Was there ever any resolution to this?