[Cableguy]

Welcome dflahe, I found a technical bulletin.
Make: CHEVROLET
Model: CHEVROLET TRUCK
Year: 2003

Service Bulletin Number: 031803
NHTSA Item Number: 10001891
Summary Description:
A CLUNK NOISE COMING FROM UNDER THE HOOD THAT ALSO CAN BE FELT IN THE STEERING WHEEL. *TT *JB
Service Bulletin Num : 031803 Date of Bulletin: MAR 18, 2003
NHTSA Item Number: 10001891
I hope this helps you. BTW It says something about replacing imtermediate steering shaft, check with dealer.

 

[Cableguy]

Feel a clunky thump in the steering in my 06 Tahoe. Could this bulletin apply to me as well?

MC

Quite possibly, check with your local dealer(maybe your next oil change). I thought I seen a few years envolved.