2017 Silverado LT
CC
SB
5.3L
6-speed
3.42
68+ mph
4000 miles
So my Vibration wasn't as bad as some of the videos that I have seen posted where the water in the cup was shaking all over the place. It also did not make any audible shaking sounds, but I could feel it. I noticed it on my first long trip with the truck and thought it might be a bad balance on the tire or something.
I took it to the local chevy dealer and they ran the picoscope on it. They confirmed that it did have a vibration.
It had a 15.3 mg Tire 1 vibration @ 14.1hz. They replaced the steering gear bushings and said that I had a defective Passive Exhaust Valve and installed a new exhaust from the Cat back.
They ran the picoscope again and the amplitude was down from 15.3mg to ~3.5mg at 14.0hz.
I have only had one short highway trip and it feels a little better. I will report back when I get a good run at highway speeds.
Thanks to everyone who has contributed to this thread.