2012 Chevrolet Sonic - Harmonic Balancer

What is a Harmonic Balancer?

The harmonic balancer, also known as the crankshaft damper or engine vibration damper, is a component mounted on the front of the engine's crankshaft that helps absorb and reduce engine vibrations for smooth operation. As the engine runs, it generates vibrations that can cause the crankshaft to twist and flex. The harmonic balancer absorbs and dampens these forces, preventing them from causing damage to other engine components and minimizing wear and tear on the crankshaft bearings. In some vehicles, the balancer may also be attached to a crankshaft pulley to run the accessory belt drive, and power components like the alternator, power steering pump, and air conditioning compressor. Harmonic balancers are typically designed with an inner ring that includes the keyway and shaft opening for the crankshaft, a weighted outer ring, and a rubber insulator between the two. In some cases, they may also have marks that are used to help time the engine properly. Over time, the harmonic balancer may suffer wear, including damage to the rubber insulator that may cause it to fail. If the balancer fails, the first sign will be engine vibration. You may also notice worn belt edges or squeaking noises while the engine is running. Repairing a problem with the harmonic balancer promptly can help save on more costly damage to other vehicle systems like the transmission, alternator, or power steering pump. Harmonic balancers also usually have to be pressed on and off of the engine, and the specialty tools to service most harmonic balancers are available in our Loaner Tool program. When you need to repair your harmonic balancer, shop O'Reilly Auto Parts, where we carry replacement harmonic balancers, crankshaft seals, and specialty harmonic balancer tools to assist in removal and installation.