Steering column noise/vibration

I have got an 05 Tahoe and at slow speeds, mainly when turning I get a clunking noise/vibration in the steering column... all most feels like I have a lose tire. There steering feels tight but there is something lose somewhere... I have felt this on other Tahoe and Yukons.... but mine seems pretty bad... any ideas on what this could be?

If you do a search, you will find many posts on this issue.
It is the intermediate steering shaft causing this.