This is a know issue with GM. They went to a 5 bolt system instead of the 6 they used in the past. The bolts are also low quality causing them to break off. My mechanic has done numerous replacements on escalades over the years to drill out and replace these bolts. I was told years ago from the dealer that the ticking was a common noise and nothing to worry about. Well now that the bolts have been replaced the ticking is gone. It's a shame to save a few dollars on quality bolts it cost me almost $1000 to fix.