I've got steering wheel moan in my 2004 GMC Sierra. It happens only when turning the wheel to the left and/or returning it back to center after a left turn. PS fluid levels have been checked and are fine. I did the steering clunk fix (zerg fitting and grease) some time ago and am sure it's not the intermediate shaft 'clunking' as it's prone to do. I talked to a mechanic who basically said, 'don't worry about it', however it grates on my nerves and I want to identify and fix the problem. The sound seems to come from column, itself. Any thoughts as to where/what I should be looking at for this?