Drive Belt Tension Check
DRIVE BELT TENSION CHECK AND ADJUSTMENTGENERATOR DRIVE BELT TENSION CHECK WHEN USING SCAN TOOL MB991958
Required Special Tools:
^ MB991668: Belt Tension Meter Set
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991910: M.U.T.-III 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 MB991910 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 of ±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
NOTE: Because the frequency depends on the belt material, confirm Part No. shown on the reverse of the belt.
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 pounds)
BELT DEFLECTION CHECK
Apply approximately 98 N (22 pounds) 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 inch)