Are you familiar with the term "torsional vibration"? Well, torsional vibration is simply a periodic vibration which would result from the twisting of an object around its axis. In your GMC truck or SUV, this vibration would be expected to originate from the crankshaft as the engine tries to turn it. Excessive torsional vibration, however, is unwanted because it may cause various damages not only to the crankshaft but to the engine itself. Thanks though to the GMC harmonic balancer because with it, you will no longer have to worry about torsional vibration and its effects.
Torsional vibration occurs because of the uneven distribution of power in the engine's crankshaft. As the engine fires, much of the power it produced is taken by the front end of the crankshaft. This causes the front end to move before the rear end does, resulting in a twisting motion. This front end twisting, and its eventual unwinding as power is removed, causes torsional vibrationa vibration that can be avoided by using a harmonic balancer.
The GMC harmonic balancer is a component that attaches to the front end of your GMC's engine crankshaft to prevent torsional vibration. Also called crank pulley damper or vibration damper, a harmonic balancer is actually made up of three parts: a steel inner part which bolts to the crankshaft; a steel outer part that have grooves for the belt; and a rubber disk or spring loaded discs, or both, in between the two steel parts. As the engine tries to turn the crankshaft, it ends up twisting the rubber part of the damper instead. Thus, twisting of the crankshaft is prevented and its smooth rotation is ensured.
The harmonic balancer can efficiently prevent excessive torsional vibration, although only if it is in good working condition. Once damaged or worn out, it would spell fatigue and fracture for the crankshaft, destruction for the couplings, and inefficiency for the engine. That's why it is important to check on the condition of the vibration damper of your GMC regularly. Once damaged or worn out, it is advisable that it be replaced immediately.