POWER STEERING OIL PUMP AND A/C COMPRESSOR DRIVE BELT TENSION CHECK AND ADJUSTMENT


DRIVE BELT TENSION CHECK
caution
  • When checking the drive belt tension, make sure that the engine is cold.
  • Check the drive belt tension after turning the crankshaft clockwise one turn or more.
Check the drive belt tension in the following procedure.

Standard value:
Item
 When checked
 When adjusted
 When replaced
Vibration frequency Hz
 142 - 182
 163 - 182
 192 - 208
Tension N
 294 - 490
 392 - 490
 542 - 640
Deflection mm (Reference)
 9.9 - 13.4
 9.9 - 11.5
 8.0 - 9.2

<When the vibration frequency is measured: Recommendation>

1.Connect special tool microphone assembly (MB992082) to special tool belt tension meter (MB992081) of special tool belt tension meter set (MB992080).
2.Press the "POWER" button to turn on the power supply.
3.Check how the belt tension meter is set (Refer to GROUP 00 - Precautions Before Service - Belt Tension Meter Set ).
4.Press "Hz" button twice to change the display to the frequency display (Hz).

5.
caution
  • 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 is 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.
Hold special tool MB992080 to the middle of the drive belt between the pulleys (at the place indicated by arrow) where it does not contact the drive belt (approximately 10 - 15 mm away from the rear surface of the belt) so that it is perpendicular to the drive belt (within an angle of ± 15°).
6.Press the "MEASURE" button.
7.Gently tap the middle of the drive belt between the pulleys (the place indicated by the arrow) with your finger as shown in the illustration.
8.Check that the vibration frequency of the drive belt is within the standard value.
note To take the measurement repeatedly, fillip the drive belt again.
9.After the completion of the measurement, press and hold the "POWER" button to turn off the power supply.

<When tension is measured>

Use a belt tension gauge in the middle of the drive belt between the pulleys shown in the figure to check that the drive belt tension is within the standard value.

<When deflection is measured>

Apply approximately 100 N 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 is within the standard value.

DRIVE BELT TENSION ADJUSTMENT
If not within the standard value, adjust the belt tension by the following procedure.
1.Remove the air hose B (Refer to GROUP 15 - Intercooler ).

2.Loosen the idler pulley nut.
3.Loosen the adjusting bolt.
4.Temporarily tighten the idler pulley nut.
Tightening torque: 7.5 ± 2.5 N·m
5.Use the adjusting bolt to adjust the belt tension to the standard values.
6.Tighten the idler pulley nut.
Tightening torque: 50 ± 2 N·m
7.Tighten the adjusting bolt.
Tightening torque: 5.5 ± 1.5 N·m
8.
caution When checking the belt tension, turn the crankshaft clockwise one turn or more.
Check the belt tension, and readjust if necessary.
9.When the belt tension is adjusted by measuring the deflection, adjust it with a tool for vibration frequency measurement or tension measurement afterward.
10.Install the air hose B (Refer to GROUP 15 - Intercooler ).