Harmonic Balancer Torque Specsby David McGuffin
The harmonic balancer's purpose is to reduce engine vibration from the crankshaft's normal operation. When replacing your harmonic balancer, it is important to not only make sure the new harmonic balancer is identical in size to the old one, but also that the bolts are the same size and length. Although it is possible to reuse the old bolts, it is highly advisable to use new ones.
What is a Harmonic Balancer
The harmonic balancer is connected, via a drive belt, to the front of the engine's crankshaft. The harmonic balancer transfers vibration from the crankshaft through the belt and pulley system. The vibrations are then transferred to the inner hub of the harmonic balancer where an energy displacing element helps to absorb the vibrations. Without a properly functioning harmonic balancer, the engine will experience added stress on the crankshaft, leading to potential engine failure.
There are a variety of torque specifications for harmonic balancers. If the torque is not set properly, the engine vibration and running of the drive belt over the harmonic balancer can cause the harmonic balancer pulley to loosen and fly off the engine. Whistling noises may indicate looseness in the belt. Every car is different. A professional or a repair manual should be consulted for the correct torque for your vehicle.
Smaller Chevy models should have the harmonic damper bolt set to 60 foot-pounds. Larger Chevy vehicles should have a torque of 85 foot-pounds. Hemi426, smaller Chrysler and larger Chrysler motors should have a harmonic damper bolt set to 135 food-pounds. According to HotRodShack, each of the Ford 260, 302, 406 and 429-460 engines should have a harmonic damper bolt set between 70 and 90 foot-pounds.
1990s and Earlier
According to DorTorSpec, most Oldsmobile and Pontiac models in the early 1990s should have a harmonic balancer torque of 219 foot-pounds. The same manufacturers should have 110 foot-pounds for production years 1995-2000. Chevy and GMC Trucks between the years 1969 and 1996 should be set to 75 foot-pounds. All Jeeps between 1987 and 2000 should be set to 80 foot-pounds.
- sand car engine image by Clarence Alford from Fotolia.com