After checking the accessory drive belt for looseness, crack, wear or tension, replace the belt if necessary.
Inspect the figures below show the various stages of belt wear to aid in belt replacement decisions. Condition of the belt ribs is best judged where the belt is bent over one of the larger accessory drive system pulleys.
Few cracks, some wear on ribs and in grooves. Replace is not required.
Several cracks per mm. Should be replaced before chunking occurs.
Separation of rib material from backing (chunking). Replace belt immediately.