Drive Belt Diagnosis

DEFINITIONS
The following are symptomatic noises of the drive belt system:

CHIRPING
The following items are indications of chirping:
- A high pitched noise that is usually heard once per revolution of a pulley or a belt.
- It is most common on cold, damp mornings.
- Verify this condition by squirting water onto the belt. The noise will momentarily stop.

SQUEAL
The following items are indications of squeal:
- A loud screeching noise that is caused by a slipping belt (this is unusual for a belt with multiple ribs).
- The noise occurs when a heavy load is applied to the belt, such as an air conditioning compressor engagement, snapping the throttle, or slipping on a seized pulley.

WHINE
A high pitched continuous noise that may be caused by a failed bearing.

FAINT CYCLE RUMBLING
A low frequency noise heard once per revolution of the drive belt.

PILLING
The following items are indications of pilling:
- The random accumulation of rubber dust in the bottom of the multi-ribbed belt grooves.
- A small amount of pilling is normal.
- Operation of the drive belt system will not be effected unless the buildup exceeds one third (1/3) of the belt groove depth.

Drive Belt Diagnosis:

Drive Belt Squeal:

Drive Belt Whine:

Drive Belt Rumbling:

Drive Belt Vibration (Part 1 Of 2):

Drive Belt Vibration (Part 2 Of 2):

Drive Belt Falls Off:

Drive Belt Diagnosis:

Multiple-ribbed type drive belts wear evenly with their pulleys. Unusual wear indicates a correction is needed. The following diagnostic tables will aid in diagnosing drive belt system conditions.