ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – 001-052   Vibration Damper, Viscous

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Disconnect the batteries. Refer to Procedure 013-009 in Section 13.
• Remove the belt guard, if equipped. Refer to Procedure 008-001 in Section 8.
• Remove the drive belt. Refer to Procedure 008-002 in Section 8.
• Remove the fan and fan shroud, if necessary.

NOTE: Some engines use four damper capscrews while others use five damper capscrews.

Remove vibration damper.

Check the mounting web for cracks.

Check the housing for dents or raised surfaces.

Replace the damper if any of these defects are identified.

The viscous damper is filled with a silicone fluid. After many hours of use, the silicone fluid may become thicker and expand.

To determine if the damper thickness is correct, remove the paint from the damper in four locations on either side of the damper. Measure and record the thickness of the damper in four places.

Measure the thickness 3.175 mm [0.125 in] from the outside of the damper.

Replace the damper if its thickness varies by more than 0.25 mm [0.010 in].

Spray the damper with spot check developer, type SKD-NF, or equivalent.

Heat the damper in an oven (rolled lip side down) for two (2) hours.

WARNING  Wear protective gloves to reduce the possibility of personal injury when handling parts that have been heated.

Remove the damper from the oven and check for fluid leakage.

If there is leakage, replace the damper.

NOTE: Some engines use four damper capscrews while others use five damper capscrews.

Install the vibration damper.

Tighten the capscrews in a star pattern.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Install the drive belt. Refer to Procedure 008-002 in Section 8.
• Install the fan and fan shroud, if removed.
• Install the belt guard, if equipped. Refer to Procedure 008-001 in Section 8.
• Connect the batteries. Refer to Procedure 013-009 in Section 13.
• Operate the engine and check for loose parts.