How to replace the harmonic balancer

Harmonic balancers fail when the motor causes excessive vibration and the alignment marks are misaligned.

The purpose of the harmonic balancer is to dampen the harmonic oscillations that all motors produce. On many engines, the harmonic balancer is built into the crank pulley. They don't often fail, but excessive engine vibrations and misaligned timing marks are some of the symptoms of a bad or faulty crankshaft harmonic balancer.

While the steps below are the same for most engines, there are many different engine designs, so please refer to your vehicle's factory service manual for detailed instructions for your specific vehicle. In this example, we will discuss how to change the harmonic balancer on a typical rear wheel drive V-engine.

Part 1 of 1: Replacing the Harmonic Balancer

Necessary materials

Breaker (½" drive)
Combination wrench set
Paul Jack
Gear puller
Jack stands
New harmonic balancer
Screwdriver Set
Socket set (½" drive)
Tape key
Torque wrench (½" drive)
Attention: The type of puller depends on the design of the harmonic balancer.

Step 1: Prepare the car. Jack up the vehicle high enough to access the harmonic balancer located at the front of the engine and attached to the crankshaft.

Step 2 Remove the accessory drive belts.. Many modern vehicles have an automatic spring-loaded belt tensioner that can be rotated to loosen the belt.

Depending on the design, you may need an open end wrench or ratchet. In older and some newer vehicles, it is necessary to loosen the mechanical tensioner.

Attention: Use your mobile phone to take a picture of the belt pad for future reference.

Step 3: Remove the harmonic balancer bolt.. Remove the harmonic balancer bolt using a strap wrench to secure the balancer.

Hold it still by loosening the bolt with a socket and a ratchet handle or a broken bar. It will be very tight, so pull hard.

Step 4: Remove the harmonic balancer. Using a puller, place the hooks in an area that is not easily broken, such as the edge of a pulley section.

Some vehicles have threaded bolt holes in the balancer that can be used to attach a puller. Tighten the center bolt with a ratchet or a broken bar until the balance bar is free.

Attention: Most harmonic balancers are kept from rotating on the crankshaft by a key. Don't lose the wooden tree key; you will need it for reassembly.

Step 5: Install a New Harmonic Balancer. Align the key slot in the new balancer with the key for the key and carefully slide the balancer onto the crankshaft.

Make sure the keyway stays in the correct position. Install the center bolt and tighten it until the required torque is reached.

Step 6: Install the straps. Turn or loosen the belt tensioner to reinstall the belt.