B5.9G, B5.9LPG – Troubleshooting and Repair Manual – 001-052   Vibration Damper, Viscous

The vibration damper controls the torsional vibration of the crankshaft. A vibration damper is engineered for use on a specific engine model.

It is not economical to repair a vibration damper in the field. Install a new or rebuilt vibration damper if the inspection indicates that a damper is defective.

The viscous vibration damper has a limited service life. The damper
must be replaced if worn or damaged.

There are two different design vibration dampers used on the B Series engines:

1. Viscous damper (A) for engines rated at speeds above 2500 rpm.
2. Rubber element damper (B) for engines rated at speeds below 2500 rpm.

NOTE: The rubber vibration damper (B) is available either with or without the crankshaft adapter.

Remove the drive belt.

Refer to Procedure 008-002.

Remove the four capscrews.

Remove the 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.

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 damper with solvent.

Viscous Damper

The viscous damper is filled with a silicone fluid. After many hours of use, the silicone fluid can 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 3.18 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 its equivalent. Heat the damper in an oven (rolled-lip side down) at 93°C [199°F] for 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.

Measure the vibration damper’s eccentricity.

Install a dial indicator as illustrated.

Rotate the crankshaft with engine barring tool, Part Number 3824591.

Record the dial indicator movement.

NOTE: If the eccentricity is not within specification, the vibration damper must be replaced.

Measure the vibration damper wobble.

Install a dial indicator as illustrated.

Push the crankshaft to the front or rear and zero the dial indicator.

Rotate the crankshaft 360 degrees with engine barring tool, Part Number 3377371, maintaining the position of the crankshaft.

Record the dial indicator movement.

NOTE: The B Series engines have two configurations for the crankshaft pulleys and vibration dampers. Determine which configuration is used and use the appropriate steps in this procedure.

One-Piece Pulley/Vibration Damper

Install the crankshaft vibration damper.

Install and tighten the crankshaft pulley/vibration damper capscrews.

Two-Piece Pulley/Vibration Damper

Install the vibration damper.

Install and tighten the vibration damper capscrews.

Install the crankshaft pulley.

Install and tighten the crankshaft pulley capscrews.

Install the drive belt. Refer to Procedure 008-002.

Service Tip: If difficulty is experienced installing the drive belt (the belt seems too short), position the belt over the grooved
pulleys first, and then, while holding the tensioner up, slide the belt over
the water pump pulley.