What are the symptoms of harmonic balancer problems?
05-22-2015, 09:21 AM
#1
Racer
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What are the symptoms of harmonic balancer problems?
Can someone knowledgeable please describe what the symptoms of harmonic balancer problems might be? Thanks in advance.
05-22-2015, 09:33 AM
#3
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For the first 11,000 or so 2005's, the problem was the center bolt not being torqued properly and that bolt could back out allowing the balancer to come off the crank shaft.
All other problems have to do with "wobble". When looking at the balancer with the engine idling the "ribs" on the balancer should look stationary. Regardless of what some may say there is no "serviceable limit" for wobble. If the wobble is too severe the belts will start to "chirp" in a quick rhythm. And the chirp is not subtle, it's embarrassingly loud. A dealer will first try to change belts. New belts will stop the chirp for around 100 miles and it will come back as loud as before. Then they will replace the balancer.
Just looked at video above. That is a "slight" wobble and many cars will do that. No chirp, no need to replace.
All other problems have to do with "wobble". When looking at the balancer with the engine idling the "ribs" on the balancer should look stationary. Regardless of what some may say there is no "serviceable limit" for wobble. If the wobble is too severe the belts will start to "chirp" in a quick rhythm. And the chirp is not subtle, it's embarrassingly loud. A dealer will first try to change belts. New belts will stop the chirp for around 100 miles and it will come back as loud as before. Then they will replace the balancer.
Just looked at video above. That is a "slight" wobble and many cars will do that. No chirp, no need to replace.
Last edited by Walt White Coupe; 05-22-2015 at 09:48 PM.
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bigjeff1222 (07-22-2021)
05-22-2015, 10:41 PM
#6
Two things to look for when the belt starts to make noise.
The outer pulley is bonded to the inner steel section via a piece of rubber with glue on both sides. So watch the outer pulley to make sure that it tracking cleanly with the inner steel section, and is not moving all over the place in and out against the inner metal section instead as in the photo.
Look close and you can see the rubber section between the outer pulley section, and the inner steel section that bolts to the crank. when the rubber cement fails, it causes the outer pulley to move in and out against the inner metal section bolted to the crank.
The second part is the HB center bolt is a one time use stretch bolt, and it had problems coming loose in the the early C6 vets. Here the rubber bond between the two parts of the HB is fine (HB fine), but with the bolt coming loose, the entire HB starts walking out on the crank instead.
As for the solution to the loose bolt problem, it's replaced with a new bolt and washer, and it correctly torqued and loctite in place so it does not come loose again.
Now to rub salt in the wound, it either case of replacing the bolt, or replacing the HB with a ATI unit that does not have the same rubber glue problem,
car needs to be jacked up, engine supported, front cradled dropped down, and the steering rank removed before you can get to work on the HB or bolt. So it becomes a $1K job in labor real quick to work on the HB.
The outer pulley is bonded to the inner steel section via a piece of rubber with glue on both sides. So watch the outer pulley to make sure that it tracking cleanly with the inner steel section, and is not moving all over the place in and out against the inner metal section instead as in the photo.
Look close and you can see the rubber section between the outer pulley section, and the inner steel section that bolts to the crank. when the rubber cement fails, it causes the outer pulley to move in and out against the inner metal section bolted to the crank.
The second part is the HB center bolt is a one time use stretch bolt, and it had problems coming loose in the the early C6 vets. Here the rubber bond between the two parts of the HB is fine (HB fine), but with the bolt coming loose, the entire HB starts walking out on the crank instead.
As for the solution to the loose bolt problem, it's replaced with a new bolt and washer, and it correctly torqued and loctite in place so it does not come loose again.
Now to rub salt in the wound, it either case of replacing the bolt, or replacing the HB with a ATI unit that does not have the same rubber glue problem,
car needs to be jacked up, engine supported, front cradled dropped down, and the steering rank removed before you can get to work on the HB or bolt. So it becomes a $1K job in labor real quick to work on the HB.
