FYI - In my experience I have found that on our fleet of Prevost coaches, we are replacing A-arm bushings ONLY, around 400,000 - 450,000 miles based upon the unit and it is always been noise related, not performance related. So, when it does its "creaking", we find that it is noticeable, not so much when driving but when people are coming in and out of the coach or in regards to driving, when you are in a turn at 50 - 60 mph on the interstate (slight lean to the left or right). In our experience at Russell Coach we have found when replacing the A-arm Bushings, a front end alignment is required. Parts, alignment and labor, we are spending somewhere in the neighborhood of $900 - $1,300. We put approximately 75,000 - 85,000 miles a year on each unit. Any questions, feel free to call Rob Russell directly at Russell Coach 865-525-3888