Inspect the alternator belt and the fan drive belts for wear and for cracking. Replace the belts if the belts are not in good condition.
Check the belt tension according to the information in the Service Manual, "Specifications".
Slippage of loose belts can reduce the efficiency of the driven components. Vibration of loose belts can cause unnecessary wear on the following components:
- Belts
- Pulleys
- Bearings
If the belts are too tight, unnecessary stress is placed on the components. Belts that are too tight reduces the service life of the components.
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| Illustration 1 | g06103789 |
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Typical alternator (1) Mounting bolt (2) Adjusting nuts (3) Mounting bolt (4) Belt guard (5) Alternator belt | |
- Loosen mounting bolt (1), adjusting nuts (2), and mounting bolt (3).
- Turn adjusting nuts (2) to increase or decrease the drive belt tension.
- Tighten adjusting nuts (2) and torque to
200 ± 20 N·m (148 ± 15 lb ft) . Tighten mounting bolt (3). Tighten mounting bolt (1). For the proper torque, see the Service Manual, "Specifications" module.Note: If new drive belts are installed, check the drive belt tension again after 30 minutes of engine operation at the rated rpm.
- Stop the engine.
- Use the 491-2178 Belt tension meter tool to check the tension with the alternator guard installed.
Note: The current guard design allows for inspection of the belt tension without removal of the guard.
- Loosen the mounting bolt for the pulley.
- Loosen the adjusting nut for the pulley.
- Move the pulley to adjust the belt tension.
- Tighten the adjusting nut to the proper torque.
- Tighten the mounting bolt to the proper torque.
For the proper torque specifications, refer to the Service Manual, "Specifications" module.
For applications that require multiple drive belts, replace the drive belts in matched sets. Replacing one drive belt of a matched set will cause the new drive belt to carry more load because the older drive belts are stretched. The additional load on the new drive belt could cause the new drive belt to fail.