Engine Mechanical
Harmonic Balancer
A harmonic balancer bolts to the front of the crankshaft, damps twisting vibration and drives the accessory belt. We carry 42 harmonic balancers from $29 to $260 for Chevrolet engines from 1964-2020, from Dorman, Dayco, AC Delco and SKP, with fits for the Corvette, Impala and Camaro.
Shop harmonic balancer by vehicle
Why the balancer matters
Each firing pulse twists the crankshaft slightly. The balancer uses a rubber layer between an inner hub and an outer ring to absorb that vibration, which protects the crankshaft and bearings. On most engines it also carries the belt pulley and the timing marks.
With age, the rubber can crack, dry out or separate, and the outer ring can slip or wobble.
Warning signs
Look for a wobbling pulley, a belt that walks off or wears on one edge, cracked or bulging rubber between the hub and ring, and timing marks that no longer line up. Unusual vibration at certain engine speeds can also point to the balancer.
A balancer that separates can throw the belt and damage nearby parts, so replace it once you see clear signs of failure.
Choosing and installing
Match the engine size, year and belt style. Parts here are for serpentine belt systems, and some include a Woodruff key and instruction sheet. Compare the pulley grooves and diameter with your old part.
Use a proper puller and installer tool, not a hammer, as striking the balancer can damage the crankshaft thrust bearing. Use a new bolt where the maker calls for one, torque it to specification, and recheck ignition timing on engines with adjustable timing.
Harmonic Balancer questions
What happens if a harmonic balancer fails?
The outer ring can slip or separate, which can throw the belt, upset timing readings and allow damaging crankshaft vibration. Replace it at the first clear sign of rubber failure or wobble.
Is a harmonic balancer the same as a crankshaft pulley?
On many engines the balancer includes the crankshaft pulley. Some engines use a separate bolt-on pulley. Check the listing details and compare with your part.
Do I need special tools to replace a harmonic balancer?
Yes. A balancer puller and an installer tool are the standard way to remove and press it on. Hammering it into place can damage the crankshaft.