What is a harmonic balancer and what is its purpose?

A harmonic balancer? Is it something related to music? When I first heard the term, it sure felt like some sort of an instrument that Daft Punk might use to create the alien noises or the sound of the future as they like to call it. Turns out it was not! A harmonic balancer is a crucial component of the engine which helps the crankshaft last as long as possible.

To understand what a harmonic balancer is, it is important that you know how an engine works. When the cylinders in the engine are fired, the to-fro movement of the valve inside generates a torque which is then transferred to the crankshaft. The crankshaft, as we know, is the component in the engine which turns the torque generated into a rotational movement which is finally transferred onto the wheels of the vehicle.

Since the crankshaft is the one component that literally moves the vehicle, the forces acting upon it are also huge. Each time the valves in the cylinder move, the crankshaft twists but along with this, it has to experience various vibrations. These vibrations sometimes resonate with the vibrations in the crankshaft. The crankshaft is not designed to bear these resonating forces and might give in causing the vehicle to bear damages beyond repair. But that doesn’t happen, does it? Here is where the musical instrument comes in! Of course, the harmonic balancer is what I mean here by a musical instrument.

It is made of rubber and metal and is circular in nature. It is fitted to the free end (accessory drive) or the front end of the crankshaft to absorb the torsional and the resonating vibrations from the crankshaft. The device must be interference fit to the crankshaft for it to operate with maximum efficiency. It is connected to the crank pulley. It is the rubber inside the pulley which is responsible for absorbing the vibrations generated by the crankshaft and keep them at a safe level. This helps the crankshaft from failing. By dampening the vibrations, it literally becomes its lifesaver!

How long does a harmonic balancer last and when should you replace it?

This depends on how many miles you have been driving the car or how old the car has actually become. There is no fixed time for this but there are symptoms from which it can be inferred that the balancer needs a replacement.

As time goes by, the harmonic balancer attached to the crankshaft can go bad due to continuous contact with chemicals, from other elements and/or from old age. These are the factors that can cause the crankshaft to develop cracks and finally fail.

Some of the symptoms which can help you recognize that the crankshaft harmonic balancer is fading are:

• The engine sounds are louder than usual and you feel abnormal vibrations coming from the engine.
• The belt in the pulley might slip which will cause the vehicle to misfire or backfire.
• The ignition timing in the vehicle will be off.
• The vehicle might not start at all if the balancer is broken.

As soon as you get these symptoms, you need to call a mechanic or else replace the balancer yourself. I am guessing, if you were an expert you would not have been reading this piece at all. It is important that you replace the part as soon as possible because driving without it will cause severe damage to other components and the vehicle might become undrivable.

This will only burn a larger hole in your pocket so it is better to get it replaced rather than going for the naïve option of letting it be.

Replacing a harmonic balancer with a new one

Well if you really want to replace a balancer, there are both pros and cons to it. We will obviously start with the pros because we surely want to replace them, don’t we?

The pro is that a new balancer is easy to install. The con is that the balancer is hard to get off the crankshaft.

You will have to dismantle other components such as the bumper or the front fender and even the radiator. You will also have to go out and buy a harmonic balancer puller (a device used for safely removing a harmonic balancer without damaging other components in the car). They will cost you around $25 or so. There is no specific way of changing a harmonic balancer in a car as almost every engine is different. You should research out on how to exactly replace the balancer in your particular model.

First off, you will want to remove the belt from the crankshaft pulley and remove the mounting bolt off. Then the puller will help you to get it out of the crankshaft. Reinstalling is just the opposite of what you did while pulling it out which makes it easy. Once you know how to dismantle, you would know how to assemble!

Final Thoughts

It is really astonishing that cars are made with a thousand parts, each having a different function but damage in even one of them might make your life a living hell. You sure do love your car and I bet it is because of that reason you are even reading this article.

So, if there is even a small tingling feeling in your heart that the balancer in your car has some sort of damage, go get it checked out immediately. If you are confident about yourself, change it yourself with the help of the above mentioned steps because neglecting a small one like this might damage your car.