The Elite Gauge allows you to easily check three different types of wear on a serpentine belt:
This is the most difficult wear to detect on a serpentine belt. It can come in the form of side or valley wear. Side wear is typically from misalignment and can be seen on one side only and will repeat on each groove across the width of the belt. Valley wear is caused by abrasion of the pulley and debris over time.
Signs of rib cracks are indications that the belt is near retirement. If rib cracks happen prematurely and before the expected life of the belt, it may mean that your drive has excessive heat. This may be caused by a bad bearing on the drive.
The thickness of the serpentine belt is the easiest visual clue to see if your belt is worn, but it can be deceiving. The grooves of the serpentine belt are worn from abrasion during typical use.
The Elite Gauge is the only tool you need to check the life of a serpentine belt.