Belt tension should be checked initially between the first 20 to 40 hours of engine operation.
Check the belt tension. Refer to the Operation and Maintenance Manual, "Maintenance Interval Schedule" topic for the proper intervals.
To check the belt tension, apply
To maximize the engine performance, inspect the belts for wear and for cracking. Replace belts that are worn or damaged.
For applications that require multiple drive belts, replace the belts in matched sets. Replacing only one belt of a matched set will cause the new belt to carry more load because the older belt is stretched. The additional load on the new belt could cause the new belt to break.
If the belts are too loose, vibration causes unnecessary wear on the belts and pulleys. Loose belts may slip enough to cause overheating.
If the belts are too tight, unnecessary stresses are placed on the pulley bearings and on the belts. This stress may shorten the service life of the components.
Remove the belt guard. Inspect the condition and adjustment of the alternator belts and accessory drive belts (if equipped).
If the belt does not require replacement or adjustment, install the belt guard. If the belt requires adjustment or replacement, perform the following procedure to adjust the belt tension.
- An engine which is equipped with a refrigerant compressor (air conditioner), the belt for the fan drive, the alternator, and the accessories have an automatic belt tensioner.
- If the engine is not equipped with a refrigerant compressor, the alternator is used to adjust the belt tension.
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| Illustration 1 | g06409177 |
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(1) Adjusting bolt
(2) Mounting bolts | |
- Slightly loosen mounting bolts (2) and adjusting bolt (1).
- Move the pulley to adjust the belt tension.
- Tighten adjusting bolt (1) and mounting bolts (2). For the proper torque, refer to the Specifications Manual, SENR3130, "Torque Specifications".
- Install the belt guard.
If new belts are installed, check the belt tension again after 30 minutes of engine operation at the rated rpm.
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| Illustration 2 | g01075753 |
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Exploded view of the drive assembly for a water pump belt (1) Mounting bolt (2) Square hole (3) Adjusting bolt | |
- Slightly loosen mounting bolts (1) and adjusting bolt (3).
- Adjust the belt tension with a square drive in square hole (2).
- Tighten adjusting bolt (3) and mounting bolt (1). For the proper torque, refer to the Specifications Manual, SENR3130, "Torque Specifications".
- Install the belt guard.
If new belts are installed, check the belt tension after 30 minutes of engine operation at the rated rpm.