Belt Tensioner All engines use an automatic drive belt tensioner. On the 7.5L engine, there are two belts; one uses the automatic tensioner, while the alternator belt requires periodic tensioning. On all belts using an automatic tensioner, no adjustment is necessary because the tensioner adjusts for belt wear. To adjust the tension on the 7,5L engine alternator belt, loosen the adjusting bolts and rotate the alternator until the proper tension is on the drive belt and tighten the adjusting bolts. It is recommended that the belt tension indicator mark be inspected with the engine OFF at 60,000 mile (96,000 km) intervals. If the wear indicator mark is out of specification, the drive belt is worn or an incorrect drive belt has been installed. The 4.6L, 5.4L, 6.8L, all have one belt and one belt tensioner. Look at the diagram on top of the radiator or somewhere in the engine compartment.
It provides the proper tension on the serpentine drive belt.
Your Explorer has a serpentine belt tensioner which keeps the proper tension on the serpentine belt unless the tensioner has failed.
Check to make sure that the serpentine belt is ok, and that the ac clutch is working properly. Make sure that the serpentine belt has the proper tension.
It provides the proper tension on the serpentine belt so as it is not too tight or too loose.
Put the proper size wrench or socket on the pulley of the tensioner.Pull the wrench counter clockwise to release the tension on the belt.
Possible belt stretch or an idler not applying proper tension for some reason.
self ajusting idler wheel strong spring inside housing
Should automatically supply the proper tension for the serpentine belt - if not could be defective and require replacement
You have a mechanic check for proper belt tension. Trust me, in the long run this is the smartest, safest and CHEAPEST way to solve the problem.
Most cars now have a serpentine belt that drive the alternator, water pump, power steering unit, etc. The belt tension pulley is a spring loaded pulley that keeps the proper tension on all these units. It can be moved to release the tension in order to remove the belt.
If your vehicle has a serpentine belt that is used to drive the accessories ( alternator , air conditioning compressor , power steering , etcetera ) the serpentine belt has a spring loaded tensioner that is supposed to keep the proper tension on the belt ( if it is working correctly )
tension pulley is an automatic tensioner that keeps the serpentine belt at the proper tension it is a single pulley that is smooth (no grooves) usually turning clockwise with constant pressure loosens pulley for belt removal use caution pulley is spring loaded