A harmonic balancer is a heavy iron, steel or aluminum circular disk about 6 to 8 inches in diameter that is pressed onto the snout of the crankshaft. On the 454ci Chevy engine, it is located on the lower-front of the engine. Its purpose is to dampen internal vibrations (harmonics) of the engine when the crankshaft and other internal components are rotating. Without it, the engine would vibrate severely. In the case of the 454, the crankshaft is not internally balanced. It requires a balancer (and flywheel) which has additional weight placed in one area of the circumference of the balancer. Be certain to use the correct one.
Remove the radiator fan shroud, and loosen and remove all accessory drive belts. Remove the drive pulley located on the front of the balancer. Remove the balancer bolt. Attach the balancer removal tool to the old balancer with the three supplied bolts, and thread the center pulling-bolt toward the crankshaft.
Clamp a Vice-grips adjustable pliers to the flywheel to lock the engine (prevent it from turning over). Use a long wrench to screw the pulling-bolt of the balancer removal tool into (toward) the engine. This will force the arms of the tool to pull the balancer off of the crankshaft snout.
Once removed, install the new balancer onto the crank snout but do not force it any further than you are able to by hand. Thread the balancer installation tool into the crank snout bolt-hole thread. Once seated, begin turning the sleeve and nut in a tightening direction. This is a slow process, so be patient.
Continue pressing the balancer into place until it is far enough on the snout that it either seats completely against the rear radius of the snout, or it has been pressed far enough for the drive-belt pulley to align with the other accessory pulleys.
Remove the installation tool from crank snout and replace the belt-drive pulley. Reinstall the accessory drive-belts and tighten. Replace the radiator fan shroud, and remove the Vice-grip adjustable pliers from the flywheel at the rear of the engine.
