Belt produce a squeaking sound, it typically indicates that the belt surface coefficient of friction is greatly reduced, had excessive wear. If the vehicle load, and may wish to observe with the drive belt, you will find a belt, the belt tensioning device or on a belt tensioner or elastic anomaly of resistance increase. Most automatic belt tensioner at the bottom between the tensioner arm and, somewhere along the slide has a set of belt length signs of wear. The logo consists of a pointer and two or three tokens, it indicates the reference of the belt tensioner. If the pointer is outside this range, then the belt probably stretching too far, it should be replaced. Automatic belt tensioner is not installed in the car, a standard at the position between the two pulleys belt elongation measuring gauge. If a difference from the standard values, it is best to replace belt.