Regular inspection of all drive belts, tensioners and accessories should be recommended once the vehicle passes 60,000 miles. And when the belt is worn and ready for replacement, which is typically around 90,000 miles, the pulley and tensioner should also be replaced. That’s because the drive works as a system. Replacing only the belt will often result in short belt life because the tensioner likely has worn springs or the pulleys’ bearings are worn and causing a slight misalignment. Even the pulleys themselves can wear and cause reduced belt life and/or noise. Replacing the entire front end accessory drive system will result in another 90,000 miles of trouble free driving.