I also put chassis ears on the truck and you can definitely hear the noise in the T-case and rear axle. It sounds different but the intensity is about even.
I did not hear the noise in the frame, exhaust, or front axle and it was hard to tell if I heard it in the transmission.
Should have started with that.
It's a 2014 Sierra Denali 1500 with the 6.2. Crew cab, 5'8" bed, about 118,000 miles.
The noise I'm hearing can be heard at 2 and 14 seconds in the video.
I noticed the tach bouncing but was sure if that was normal for this truck or not. I'm climbing a slight hill in the video and the bouncing doesn't seem to be tied to the noise but it could be related.
Anyone know what this noise is? It's very intermittent. Seems to do it most often between 40 and 50 MPH cruising with maybe a slight up hill. Never does it on coast or heavy acceleration. Very hard to tell where it's coming from.
20190521_191545_001.mp4
2014 Sierra Denali 1500
Crewcab, 5'8" bed
6.2 Litter
3.42 axle ratio
about 118,000 miles