harmonic balancer needs replacing?

[delta5]

how can I tell, or what would be an indication that I need to replace the harmonic dampener on my series5 1725cc....im getting vibration at higher revs, yet all is running fine with the engine....or could it be engine mounts that are hardened?
any ideas?
david

 

[mikephillips]

You can inspect the rubber insert to see if it is failing and causing the pulley section to move relative to the center section. You can also see if the rim is broken or bent. But the only way to check the entire assembly though is to remove it. If it is the original you may have a crack in the center section where it slides over the crank snout, particularly in the keyway as this is increasingly common to find. The only way to see this will be with the balancer removed from the engine to see the entire length that goes into the chain cover.

 

[RootesRooter]

If the balancer's keyway had developed a crack that allowed the balancer to wobble on the crank you might get some vibration. The wobble may be visible and the nut holding it might be loose or even missing.

Still, its likely the vibration source is elsewhere. Motor mounts are a good place to start. I'd also check the bolts holding the engine-to-tranny and the oil pan-to-tranny support rods. Any chance the fan is damaged?