MBE 900 – Section 1.9 Belt Pulley and Vibration Damper

Section 1.9
Belt Pulley and Vibration Damper

The vibration damper reduces torsional vibrations to a safe value.‪

Section 1.9.1
Vibration Damper Removal

Remove the belt pulley and vibration damper as follows:‪

1. Remove the poly-V belt from the alternator, idler, A/C compressor, and coolant-pump pulleys, as installed.
2. Remove the end cover from the flywheel housing and install the engine barring tool J-46392 . Refer to "1.13.1 Engine Barring Tool Installation" .
3. Using the 16-mm flywheel and main pulley socket tool J-46385 , remove the six multipoint socket-head bolts on the vibration damper. Remove the vibration damper. See Figure "Vibration Damper Removal" .
   

   1. Vibration Damper‪	3. Poly-V Belt‪
   2. Bolt, M14 x 1.5 (6 qty.)‪

   Figure 1. Vibration Damper Removal

4. Measure the shanks on the bolts. Replace the bolts if the shanks are stretched beyond the maximum length of 61.0 mm (2.40 in.).

Section 1.9.1.1
Vibration Damper Inspection

Inspect the vibration damper for damage. Replace the damper if the external surface is damaged, or if fluid leakage is apparent.‪

Section 1.9.2
Vibration Damper Installation

Install the vibration damper as follows:‪

1. Lightly oil the threads on six M14 x 1.5 bolts.
2. Install the vibration damper on the crankshaft. Tighten the six bolts in three stages. In each stage, use an alternating tightening sequence until all six bolts are tight. See Figure "Torque Tightening Sequence for Vibration Damper" . The tightening stages specifications are listed in Table "Tightening Stages, Vibration Damper Mounting Bolts" .
   

   Figure 2. Torque Tightening Sequence for Vibration Damper

   Maximum Shaft Length‪	Tightening Stage‪	Torque Value‪
   61.0 mm (2.40 in.)‪	Stage 1‪	50 N·m (37 lb·ft)‪
   	Stage 2‪	125 N·m (92 lb·ft)‪
   	Stage 3‪	additional 90 degrees‪

   Table 2. Tightening Stages, Vibration Damper Mounting Bolts
3. Remove the engine barring tool J-46392 from the flywheel housing and install the end cover. Refer to "1.13.2 Engine Barring Tool Removal" . Tighten the end cover bolts 25 N·m (18 lb·ft).
4. Install the poly-V belt on the pulleys, as removed.