Which of these conditions does your sample look like ?

New silicone fluid is a clear / colourless fluid.
Fluid colourless to light shades of yellow / brown, and free from particles. Usually indicates no internal damage. Fluid viscosity will determine suitability of damper for further service periods.
Fluid dark brown or black in colour, usually with particles in the fluid. As a general rule, dampers with fluid in this condition have suffered internal mechanical damage and have restricted remaining service life.
A damper with gelled / solidified fluid is unsuitable for service and it should be removed from service as soon as possible as it is no longer protecting the crankshaft from torsional vibration.

Most diesel engines are fitted with one or two viscous shear type torsional vibration dampers attached to the crankshaft, at the opposite end to the flywheel.


The crankshaft damper is fitted to control the torsional vibrations developing in the crankshaft induced by the combustion process in the engine. The viscous damper, by reducing oscillations in the crankshaft to a low amplitude, keeps the material stresses arising from these vibrations within permissible design limits and prevents premature failures of the driven equipment due to fatigue.