Generator Drive Belt Tension Check
GENERATOR DRIVE BELT TENSION CHECKWhen using scan tool MB991958
Required Special Tools:
^ MB991668: Belt Tension Meter Set
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991910: MUT-Ill Main Harness A
CAUTION:
To prevent damage to scan tool MB991824, always turn the ignition switch to the "LOCK"(OFF) position before connecting or disconnecting scan tool MB991824.
1. Connect special tool MB991668 to scan tool MB991824.
2. Connect scan tool MB991910 to scan tool MB991824.
3. Connect scan tool MB991 910 to the data link connector.
4. Turn the ignition switch to the "ON" position and select "Belt Tension" from the menu scan tool MB991824 screen.
CAUTION:
^ The temperature of the surface of the belt should be as close as possible to underhood temperature.
^ Do not let any contaminants such as water or oil get onto the microphone.
^ If strong gusts of wind blow against the microphone or if there are any loud sources of noise nearby, the values measured by the microphone may not correspond to actual values.
^ If the microphone is touching the belt while the measurement is being made, the values measured by the microphone may not correspond to actual values.
^ Do not take the measurement while the vehicle's engine is running.
5. Hold special tool MB991668 (microphone) to the middle of the drive belt between the pulleys (at the place indicated by the arrow), about 10-20 mm (0.4 - 0.8 inch) away from the rear surface of the belt and so that it is perpendicular to the belt (within an angle off 15 degree angle).
6. Gently tap the middle of the belt between the pulleys (the place indicated by the arrow) with your finger as shown in the illustration, and check that the vibration frequency of the belt is within the standard value.
Standard value: 143 - 169 Hz
When using the tension gauge
Use a belt tension gauge to check that the belt tension is within the standard value.
Standard value: 490 - 686 N (110 - 154 lb)
Belt deflection check
Apply approximately 98 N (22 lb) of force to the middle of the drive belt between the pulleys (at the place indicated by the arrow) and check that the amount of deflection in within the standard value.
Standard value: 8.4 - 10.7 mm (0.33-0.42 in)