Silverado Rumbling

I have a 2007 Silverado 1500 classic, 4x2, AT, V6. Sometimes at 40-45 mph I hear a rumble…like it needs to downshift.

Sound familiar to anyone? Should I be concerned?

Noises are very hard to diagnose on the Net.

What I would do is go to a dealer and test drive another identical truck and see for yourself.

It’s under warranty right?

Investigating and diagnosing strange noises, vibrations, etc. is foremost in preventive maintenance. Always be concerned to some degree.