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Three Reasons for Harmonic Balancer Replacement

A harmonic balancer is not just there to spin the rest of the pulleys on the engine. It’s designed to help smooth out the engine’s harmonics to a level that allows little vibration into the cabin of the car. Made up of just three parts – the hub, which is usually keyed and bolted to the engine, the rubber damper, and the outer ring – the balancer is tuned through sizing, balance and other factors to dampen the power pulses of the engine and provide smooth operation. If it needs to be replaced, its likely one of the following three reasons.

1. There’s an oil leak from the front crankshaft seal. The balancer has a machined smooth surface that the front crank seal rides on. The seal is a double lip spring-loaded silicone rubber seal that allows crank rotation while keeping the oil in the crankcase where it belongs. With time, wear and dirt intake, the seal may begin to leak. It will almost always cause a groove to be worn into the machined area of the balancer so both the balancer and the seal will need to be replaced to repair the leak.

2. When the rubber that binds the two parts of the balancer together is exposed to oil or other contaminants, it will deteriorate, and the balancer will not function properly. It may also deteriorate from environmental conditions like high heat, dirt roads or even ozone damage. If this is the case, the car will have unexplained vibration, especially at idle and high speeds. A close inspection of the rubber will tell the story but harmonic balancer replacement may be necessary.

3. The engine is rebuilt or remanufactured. You do not want to go through the expense of rebuilding an engine and then refit it with an old worn-out balancer. Start any new engine with a fresh balancer for a quality rebuild that will run smoothly and last a long time.

Dayco’s OEM replacement balancers feature the strength and durability of bonded dampening rubber at a price point attractive to techs and engine rebuilders. Many offshore-made balancers use inexpensive gray iron castings. Dynamically balanced at the factory, the PowerBond™ by Dayco balancer uses only strong SG iron for maximum strength and durability. Most OEM balancers use press inserted dampening rubber that can be prone to spinning and dislocation in high torque serpentine belt applications. The bonded dampening rubber in Dayco’s OEM design is four times the strength of press inserted rubber balancers