WASHER-HARD 4512179 - Caterpillar

Rubber Damper
Your engine may be equipped with a rubber damper. The rubber damper uses a ring which is mounted in rubber in order to reduce vibrations in the crankshaft. Inspect the damper and repair or replace the damper for any of the following reasons:
There is deterioration and cracking of the rubber.
There is slippage of the outer ring from the original position.
The engine has had a failure because of a broken crankshaft.
Analysis of the oil has revealed that the front main bearing is badly worn.
There is a large amount of gear train wear that is not caused by lack of oil.Refer to the Service Manual or consult your Caterpillar dealer for information about damper replacement.Visconic Damper
Your engine may be equipped with a visconic damper. The visconic damper has a weight that is located inside a fluid filled case. The weight moves in the case in order to limit torsional vibration.Inspect the damper for evidence of fluid leaks. If a fluid leak is found, determine the type of fluid. The fluid in the damper is silicone. Silicone has the following characteristics: transparent, viscous, smooth and difficult to remove from surfaces.If the fluid leak is oil, inspect the crankshaft seals for leaks. If a leak is observed, replace the crankshaft seals.Inspect the damper and repair or replace the damper for any of the following reasons:
The damper is dented, cracked, or leaking.
The paint on the damper is discolored from heat.
The engine has had a failure because of a broken crankshaft.
Analysis of the oil has revealed that the front main bearing is badly worn.
There is a large amount of gear train wear that is not caused by a lack of oil.Refer to the Service Manual or consult your Caterpillar dealer for information about damper replacement.