| Table 1: | Chirping |
| Table 2: | Drive Belt Squeal |
| Table 3: | Drive Belt Whine |
| Table 4: | Drive Belt Rumbling |
| Table 5: | Drive Belt Vibration |
| Table 6: | Drive Belt Falls Off |
| Table 7: | Excessive Wear in Either Outside Groove of Drive Belt |
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. |
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.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Check for misalignment of the pulleys. Are any of the pulleys misaligned? | -- | ||
2 | Replace any misaligned pulleys. Is the chirp still present? | -- | System OK | |
3 | Check for bent or cracked brackets. Are there any bent or cracked brackets? | -- | ||
4 | Replace any bent or cracked brackets. Is the chirp still present? | -- | System OK | |
5 | Check for any loose or missing fasteners. Are there any loose or missing fasteners? | -- | ||
6 | Tighten any loose fasteners and properly install any missing fasteners. Refer to Fastener Tightening Specifications . Is the chirp still present? | -- | System OK | |
7 | Check for a bent pulley flange. Is the pulley flange bent? | -- | ||
8 | Replace the pulley flange. Is the chirp still present? | -- | System OK | |
9 | Check for severe pilling, exceeding 1/3 of the belt groove depth. Is there severe pilling? | -- | -- | |
10 | Replace the accessory drive belt. Refer to Drive Belt Replacement . Is the chirp still present? | -- | -- | System OK |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Check for a misaligned pulley. Is there a pulley misaligned? | -- | ||
2 | Check for incorrect belt length. Is the belt length correct? | -- | ||
3 | Repair or install new parts as necessary. Is the repair complete? | -- | System OK | -- |
4 | Check for a malfunctioning drive belt tensioner. Is the tensioner malfunctioning? | -- | ||
5 | Check for correct pulley size. Are the pulleys the correct size? | -- | ||
6 | Check for siezed bearings. Is there a siezed bearing? | -- | System OK |
Step | Action | Value | Yes | No |
|---|---|---|---|---|
1 | Check for a worn accessory component bearing. Is a bearing making the noise? | -- | System OK | |
2 | Install new parts as necessary Is the repair complete? | -- | System OK | -- |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Check for severe pilling. Is there severe pilling of more than 1/3 of the rib depth? | -- | System OK | |
2 | Clean the drive belt pulleys. Are the drive belt pulleys clean? | -- | ||
3 | Install a new accessory drive belt. Is the repair complete? | -- | System OK | -- |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Check for loose or missing fasteners. Are there loose or missing fasteners? | -- | ||
2 | Tighten or replace as necessary. Refer to Fastener Tightening Specifications . Is the repair complete? | -- | System OK | -- |
3 | Check for damaged fan blades. Are the fan blades damaged? | -- | ||
4 | Replace as necessary. Refer to Cooling Fan Motor Replacement - Electric in Engine Cooling. Is the replacement complete? | -- | System OK | -- |
5 | Check for a bent fan clutch or coolant pump shaft. Is the fan clutch or coolant pump shaft bent? | -- | ||
6 | Replace as necessary. Refer to Water Pump Replacement in Engine Cooling. Is the repair complete? | -- | System OK | -- |
7 | Check for bent or cracked brackets. Are there bent or cracked brackets? | -- | System OK | |
8 | Replace the brackets as necessary. Is the repair complete? | -- | System OK | -- |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Check for a misaligned or a bent pulley. Are the pulleys misaligned? | -- | ||
2 | Replace any misaligned or bent pulleys. Does the drive belt continue to fall off? | -- | System OK | |
3 | Check for a bent or a cracked bracket. Are any of the brackets bent or cracked? | -- | ||
4 | Replace the damaged brackets. Does the drive belt continue to fall off? | -- | System OK | |
5 | Check for loose or missing fasteners. Are there any loose or missing fasteners? | -- | ||
6 | Replace any missing fasteners and tighten to specifications. Refer to Fastener Tightening Specifications . Does the drive belt continue to fall off? | -- | System OK | |
7 | Check for a misaligned power steering pump pulley. Is the power steering pump pulley misaligned? | -- | ||
8 | Align or replace the power steering pump pulley. Refer to Power Steering Pulley Replacement in Power Steering. Does the drive belt continue to fall off? | -- | System OK | |
9 | Check for a damaged drive belt. Is the drive belt damaged? | -- | ||
10 | Replace the accessory drive belt. Refer to Drive Belt Replacement . Does the drive belt continue to fall off? | -- | System OK | |
11 | Check for a malfunctioning drive belt tensioner. Is the drive belt tensioner malfunctioning? | -- | ||
12 | Replace the drive belt tensioner. Refer to Drive Belt Tensioner Replacement (Accessory) . Does the drive belt continue to fall off? | -- | System OK | |
13 | Check for a worn or wobbling idler pulley. Are the idler pulley bearings worn? | -- | -- | |
14 | Replace the idler pulley. Does the drive belt continue to fall off? | -- | -- | System OK |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Check to see if the ribs in the drive belt match the grooves in the pulley. Do the ribs in the drive belt match the grooves in the pulley? | -- | -- | |
2 | Replace the accessory drive belt. Refer to Drive Belt Replacement . Is the repair complete? | -- | System OK | -- |
General Instructions
- Use the service manual, owners manual or the lable located on the drivers side inner fender to illustrate the correct way to route the drive belt over the pulleys.
- Each rib of the drive belt should rest inside a corresponding groove the pulley.
- When installing a new drive belt, observe the indicator on the tensioner.
A new drive belt should fall within the specified range indicated on the tensioner.
