N14 Base Engine Troubleshooting and Repair Manual – 001-052   Vibration Damper, Viscous

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

Clean the vibration damper with solvent.

Inspect the vibration damper mounting area for cracks.

Check the housing for dents or raised surfaces.

Replace the damper if any defects are identified.

Record the vendor identification, date code, and part number.

Using the date code, determine the type of bearing material in the damper.

• Date codes followed by a “P” represent dampers with teflon bearing material.
• Date codes that are not followed by a “P” represent dampers with nylon bearing material.

Determine if the vibration damper is a cast type or fabricated type.

Fabrication vibration dampers are the most common type and can be identified by a weld bead on the front center section of the damper where the housing joins the mounting flange.

Remove the paint on both sides of the damper in four locations spaced 90 degrees apart.

Measure and record the thickness at two points on each of the four locations.

• Measure the thickness at 3.18 mm [0.125 in] from the outer lip.
• Measure the thickness at 25.4 mm [1.0 in] from the outer lip.

This procedure will result in a total of eight measurements.

If the variations between any of the eight measurements exceeds 0.25 mm [0.010 in], or if the thickness at any point exceeds the maximum thickness dimensions indicated below in the table, the damper must be replaced.

Replace the small vibration damper with a large vibration damper, if the small vibration damper fails inspection or the engine experienced a camshaft nose failure.

Spray the rolled lip of the vibration damper with crack detection developer, Part Number 3375434, or equivalent.

Heat the damper in an oven, rolled side down, at 93°C [200°F] for two hours.

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

Remove the damper from the oven and check for fluid leakage around the rolled lip.

If the vibration damper has leaks, it must be replaced.