Dayco 89477 Belt Tensioner Assembly

drivers and mechanics of heavy-duty vehicles know that front-end accessory drive components may last for quite some time but eventually do where and must be replaced to retain proper performance that includes both serpentine belts and belt tensioners in this video we're working on a 2004 Freightliner truck equipped with a Detroit Diesel series 60 14 liter engine this truck has over four hundred eighty-six thousand miles on it and is due for a look under the hood before beginning any work on the engine make sure you have taken the necessary safety precautions such as setting the parking brake removing the keys from the ignition and disconnecting the vehicles battery there are several ways to inspect a tensioner while the engine is running if you hear any noise coming from the tensioner it may be a good idea to check the tensioner with the engine shut off if the serpentine belt is trackin