When turning hard one way or the other and you hear a POP, more than likely a ball-joint issue. Many techs will check alignment and fix what they see at that time. When you have a out of center steering wheel issue the front end alignment needs to me completely redone from the start. Simply getting one side back into alignment does not fix all issues!! The problem with all vehicles shops these days the techs are required to go by the appropriate vehicle service manual which tells them step by step what the troubleshooting/repair procedure is. They are not allowed to deviate from the manual even though at times common sense tells them to do so! This is because GM, Ford, RAM, etc is footing the bill for a warranty repair and will not pay them to do something that is not in the manual. Most dealer mechanics are also paid "By the job". If it takes a mechanic 1 hour to complete what the book says takes an hour, he is paid for 1 hour. If it takes him 2 hours he is still paid for 1 hour. On the other hand if it takes him 30 minutes to complete it, he is still paid for 1 hour. All that being said, "Most" dealer mechanics will rush through jobs to get as many jobs completed in a day which in turn puts more money in his and the dealers pocket. So, what all that means is "Most" dealers could care less if the job gets the problem fixed or not. If it does great, if it doesn't the manufacturer will pay them to work on it again!! However, a "Non-Dealer" shop will do whatever it takes to fix the issue because once they are paid they don't want the vehicle back to be fixed again on their dime!! Sorry for the rant but having repeat issues with vehicles over the years, and knowing a GM Service manager, I know this to be fact!