Drive Belt: Testing and Inspection
DRIVE BELT (FOR THE GENERATOR, WATER PUMP, POWER STEERING PUMP (CHECK CONDITION)GENERATOR DRIVE BELT TENSION CHECK
Required Special Tools:
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: Vehicles Communication Interface (V.C.I.)
^ MB991827: MUT-III USB Cable
^ MB991911: Main Harness B (Vehicles without CAN communication system)
^ MB991668: Belt Tension Meter Set
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect special tool MB991668 to the scan tool MB991958.
2. Connect scan tool MB991958 to the data link connector.
3. Turn the ignition switch to the "ON" and select scan tool MB991958 "Belt Tension Measurement" from the menu screen.
4. 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).
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. 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
Use a belt tension gauge to check that the belt tension is within the standard value.
Standard value
Apply 98 N (22 pound) 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
GENERATOR DRIVE BELT TENSION ADJUSTMENT
<2.4L ENGINE>
1. Loosen the nut of the generator pivot bolt.
2. Loosen the lock bolt.
3. Turn the adjusting bolt to adjust the belt vibration frequency, belt tension or deflection to the standard value.
Standard value
4. Tighten the lock bolt.
Tightening torque: 23 ± 2 Nm (16 ± 2 ft. lbs.)
5. Tighten the nut of the generator pivot bolt.
Tightening torque: 44 ± 10 Nm (33 ± 7 ft. lbs.)
6. Tighten the adjusting bolt.
Tightening torque: 4.9 ± 1.0 Nm (44 ± 8 inch lbs.)
<3.0L ENGINE>
1. Loosen the tensioner pulley fixing nut.
2. With the tensioner pulley fixing nut temporarily tightened to 15 ± 5 Nm (11 ± 4 ft. lbs.), set the belt tension or defection amount to the standard value using the adjusting bolt.
Standard value
3. Tighten the tension pulley fixing nut.
Tightening torque: 49 ± 10 Nm (36 ± 7 ft. lbs.)
POWER STEERING OIL PUMP DRIVE BELT TENSION CHECK AND ADJUSTMENT
Check the drive belt tension by the following procedure.
Required Special Tools:
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: Vehicles Communication Interface (V.C.I.)
^ MB991827: MUT-III USB Cable
^ MB991911: Main Harness B (Vehicles without CAN communication system)
^ MB991668: Belt Tension Meter Set
Gently tap the middle of the belt between the pulleys (the location 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.
NOTE: Refer to for details on the method of measuring the vibration frequency using the scan tool.
Use a belt tension gauge to check that the belt tension is within the standard value.
Apply 98 N (22 pound) 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.
Standard value
<2.4L ENGINE>
<3.0L ENGINE>
if the tension or deflection is outside the standard value, adjust by the following procedure.
<2.4L ENGINE>
1. Loosen the tension pulley fixing nut A behind the tension pulley.
2. Adjust the belt deflection amount using the adjusting bolt B.
3. Tighten the fixing nut A.
Tightening torque: 44 ± 10 Nm (33 ±7 ft. lbs.)
CAUTION: Check after turning the crankshaft one or more rotation clockwise.
4. Check the belt deflection amount and tension, and readjust if necessary.
<3.0L ENGINE>
1. Loosen the tension pulley fixing nut and bolt.
2. Adjust the belt tension using the adjusting bolt.
3. Tighten the fixing nut and bolt.
Tightening torque: 44 ± 10 Nm (33 ± 7 ft. lbs.)
CAUTION: Check after turning the crankshaft one or more rotation clockwise.
4. Check the belt deflection amount and tension, and readjust if necessary.