Symptoms of a Bad or Failing Crankshaft Harmonic Balancer ...
The crankshaft harmonic balancer is a device connected to the front of an engine''s crankshaft, usually built into the crankshaft pulley. Its purpose is to absorb and reduce harmonic vibrations from the engine as the crankshaft rotates, as harmonic vibrations at high engine speeds can cause accelerated wear and damage to the components.