Harmonic Balancer

[coxfmly]

What is the normal life span for a harmonic balancer? would it be worth changing if i'm in the area (removing radiator this weekend). I seem to have a harmonic imbalance at 65 mph. this is a very specific "vibration" that comes on at 65 only. 64 is fine as well as 66 mph. I've checked the universal joints, drive shafts, rear end and have had the tires rotated and balanced. If I change it out, is there a special one or type i should buy? thanks

[Subzilla]

Assuming they were the original, I changed both of mine at about 230k miles because of rubber condition. I wouldn't replace one just on mileage but rather a visual inspection of the rubber between the inner and outer rings. Check for cracking, bulging, separation, chunking off... Any of these, you should immediately replace it. But if you have the dampener off and it's got some miles, you might as well repace it. I purchased from Team Chevy in Scottsbluff, NE (800-658-4017) and saved many buckos from the local stealership.