Drive Belt Tensioner: Testing and Inspection
DESCRIPTIONAutomatic drive belt tensioners (6B209) are spring-loaded devices which set and maintain the drive belt tension. The drive belt (8620) should not require tension adjustment for the life of the drive belt. The automatic drive belt tensioner can be checked as follows:
ENGINE RUNNING
With the engine running, observe drive belt tensioner movement. The drive belt tensioner (6B209) should move (respond) when the A/C clutch cycles or when the engine is accelerated rapidly. If the drive belt tensioner movement is constant without A/C clutch cycling or acceleration, a pulley or shaft is probably bent or a pulley is out of round. In rare cases, excessive drive belt rideout (uneven depth of grooves in drive belt (8620)) can cause excessive drive belt tensioner movement. This condition can be checked by replacing the suspect drive belt with a known good original equipment drive belt and repeating the observation.
ENGINE OFF
1. With engine OFF, check for proper routing of the drive belt. Service as required.
2. The automatic drive belt tensioner has drive belt indicator marks. If the indicator mark is not between the MIN and MAX marks, the drive belt is worn or an incorrect drive belt has been installed. Replace the drive belt as required.
3. Rotate the drive belt tensioner and check for a binding or frozen condition. Replace tensioner if required.