I am the original owner of my 2007 Silverado Classic. Currently at 172k and running pretty much like new. I couldn't be happier with this truck.

However, in the past year or so, it's developed a weird sort of rattle that appears to be under the dash. It's more pronounced over small bumps and sounds almost like marbles bouncing around.

Today, I removed the instrument cluster and lower kick panel and took it for a short drive with my mechanic's stethoscope. It appears the noise is coming from the steering column itself. The noise is loudest when probing the steering column near where it is bolted to the support bracket, behind the dash.

I've checked all fasteners in this area, as well as inspected the steering column shaft that connects to the rack and pinion, with no looseness detected, with the universal joint also feeling rather tight.

Any insight would be appreciated.

 

Our 05 Suburban had an irritating clunk in the column. I believe it was repaired under a bulliten recall of some sort; long time ag, don't remember anything more about it

 

yup. good idea to review the bulletins for your vehicle

https://www.nhtsa.gov/vehicle