Corvair Harmonic Balancer
Most new Corvair owners respond with a, “ what’s that?” when another states the car needs a new Harmonic Balancer. Of all the parts in a Corvair, it is by far the least understood and hardest to part to locate even though it is fully exposed. It sounds like a musical instrument. Many cars today have these.
All Corvairs made from 1964 onwards have this. The balancer is a damper. It consists of a solid metal inner piece that attaches to rear nose of the crankshaft and a solid metal outer ring in which the fan belt goes around. If you see the lower ring with the belt, the balancer is on the same ring but behind it. The Balancer is a safety device that protects your crankshaft. The outer and inner portions have a rubber spacer between them and tuned to vibrate at 205-225 cycles per second (CPS). As the engine operates it vibrates and oscillates and the balancer acts as a sponge damper to defer and soak these up vibrations. If not, the engine crankshaft would become very damaged and crack and ruin your engine. It sounds crazy, but it is there for a reason!
After many years, the rubber separator deteriorates and no longer holds the pieces together well. One symptom is a loud obnoxious sound, I mean a sound that forces you to look at the engine. Or, perhaps, a piece of it comes apart while moving and rips into your oil filter causing a big mess, or you are unable to time your engine with a timing light no matter how you try because the outer ring rotates separately than in sync with the balancer.