2003 Cheverolet Suburban

I own a 2003 Chevy Suburban with a clanking sound in the front left. The noise is very annoying and happens anytime go over small bump. I have had it in to the Dealer 3 times where they have greased front end, tighten bolts front end, and finally replaced the intermediate steering shaft with no avail. I am taking it back next week would like to find out more info. After asking around I found two of my sister in laws with same problem on their Suburbans 2003 and 2004 models. They also have taken their Suburbans in several times to different dealers with no fix.