Drive Belt: Testing and Inspection

ACCESSORY DRIVE BELT

VISUAL DIAGNOSIS





When diagnosing serpentine accessory drive belts, small cracks (1) that run across the ribbed surface of the belt from rib to rib, are considered normal. These are not a reason to replace the belt. However, cracks (2) running along a rib (not across) are not normal. Any belt with cracks running along a rib must be replaced. Also replace the belt if it has excessive wear, frayed cords, severe glazing or chunking.
Any belt with bumps, surface coming apart, or any other uneven indications along the flat surface of the belt must be remove and inspected and replaced if necessary.

NOISE DIAGNOSIS

ACCESSORY DRIVE BELT DIAGNOSIS CHART (part 1):

ACCESSORY DRIVE BELT DIAGNOSIS CHART (part 2):

ACCESSORY DRIVE BELT DIAGNOSIS CHART (part 3):

Noises generated by the accessory drive belt are most noticeable at idle. Before replacing a belt to resolve a noise condition, inspect all of the accessory drive pulleys for alignment, glazing, or excessive end play.