Operation CHARM: Car repair manuals for everyone.

Drive Belt Problems

DRIVE BELT PROBLEMS

Loose Belts - Belts which are tensioned too loosely will slip on the pulleys when a load is placed on them (Fan clutch engages, engine speed increases).

Belts Tensioned Too Tightly - Excessive drive belt tension will place pressure on the water pump seals and bearings. This may result in a premature failure of the water pump.

Incorrect Belt Routing - Drive belts may be incorrectly routed in a way that reduces the total contact area between the belt and pulley. This allows the water pump or fan pulley to slip although the belt may have been tightened to the correct tension.




Belts Aligned Incorrectly - The drive belt does not line up straight between the drive pulley and operating pulley. This may result in premature belt failure or belt squeal.



Incorrect Belt Type - The drive belt should fit properly, the width of the belt should match the width of the pulleys.

SYMPTOMS
Loose/Incorrectly Routed Belts
- Vehicle overheats under low speed (less than 25 mph) or high load conditions:
- High temperatures.
- A/C operation.
- Climbing long steep hills.
- Belt squeal (resulting from the belt slipping on the pulley).

Belt Tensioned Too Tightly
- Repetitive water pump failure.
- Repetitive drive belt failure.

Incorrect Belt Type / Belt Alignment
- Belt chirping.
- Premature belt wear (edges frayed).

HOW TO VERIFY
With the engine "OFF" and the ignition key removed
- Check drive belt tension. Drive Belt

NOTE: As a general rule you should not be able to turn the pulleys by hand, if the pulley rotates and the belt slips, the belt is too loose.

- Check drive belt condition. The belts should not be frayed or glazed.

NOTE: Glazed belts have a shiny/glassy appearance along the friction surface, resulting from belt slippage on the pulley. Once a belt is glazed it may tend to slip even with the correct belt tension applied. Glazed belts should be replaced.

- Check the pulley alignment. Pulleys which are out of alignment may be the result of:
- Improper parts installed.
- Worn bearings or bent brackets.
- Improper arrangement of washers or shims.

NOTE: If a component has recently been replaced, verify the installation is correct