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I want to hear from somebody, anybody, who has personally had an HB actually fail on a stock LS2/LS3. We are all out there replacing our HB's like *****'s, and more than half the people who own C6's don't even know what it is, where it is, or what it does. They just drive on, miles upon miles, and we never here of a single incident from anyone it personally happened to.
I'm not being contrary, but I have yet to read of one, single, failure on a stock LS2/3. Have we unnecessarily created a cottage industry of HB replacement???
Well said buck, and i'll be interested in some of the replies.....
Also. If the balancer is wobbling and the belts are chirping then the part has FAILED. Just because the pullies aren't flying out of the hoods doesn't mean they haven't failed. If the part is no longer working to spec it has failed. Wobbling too much is failing.
Catastrophic failures are very rare. Probably because then the belts start chirping the part is getting replaced before it does fail catastrophically.
Are you suggesting that a balancer with a 1/64th of an inch run-out and/or wobble has failed and should be replaced ??......
Would you be so kind to give us your def of "failed"....
This is an excellent comment!!! I struggle with this myself. We have two vettes in the family.
1st vette .. slight chirp when cold, wobble maybe a 1/16 inch. I'm not fixing it as it seems fine at 49K and same as several other 'vettes I've looked at.
2nd vette .. slight chirp always, very noticeable wobble - maybe 3/16 inch and 90K miles and didn't seem bad at the time. Then at 92K the outer ring moved backwards and hit the timing cover and almost ground through it and the oil pan.
If anyone has a way to test the HB like to know about it. Don't want to go through the 2nd case again.
Mine definitely failed. Noticed the belts chirping and after looking at the HB there was a very noticeable wobble. Had it replaced and the mechanic brought out the old part and you could see where the outer ring had walked backwards towards the engine. Much more and it would have been touching and causing additional damage.
As said...it failed and certainly needed replaced.
Also. If the balancer is wobbling and the belts are chirping then the part has FAILED. Just because the pullies aren't flying out of the hoods doesn't mean they haven't failed. If the part is no longer working to spec it has failed. Wobbling too much is failing.
Catastrophic failures are very rare. Probably because then the belts start chirping the part is getting replaced before it does fail catastrophically.
jared,
Your definition of failure is correct, though it is not the "catastrophic" failure I was curious about. One of the objects of my original question is to determine when the appropriate replacement action should occur.
My pulley was wobbling some, and I had it replaced. Others have experience wobble and chirping (which I did not). Still others have never even looked at the piece, or know what it is, and have not replaced anything. Obviously, some/many have a pulley that wobbles, but never fails. Replacing that item is a significant cost, possibly unnecessary. Is the "chirping belt" the definition of failure? I don't know but am curious about it, that's all.
This is an excellent comment!!! I struggle with this myself. We have two vettes in the family.
1st vette .. slight chirp when cold, wobble maybe a 1/16 inch. I'm not fixing it as it seems fine at 49K and same as several other 'vettes I've looked at.
2nd vette .. slight chirp always, very noticeable wobble - maybe 3/16 inch and 90K miles and didn't seem bad at the time. Then at 92K the outer ring moved backwards and hit the timing cover and almost ground through it and the oil pan.
If anyone has a way to test the HB like to know about it. Don't want to go through the 2nd case again.
Dutch, that is a great reply. Thank you for the info. As some have said, their pulley started wobbling prior to 20K, so they had it replaced. In some cases, it wobbled again, and was replaced again (with a factory part, ugh).
Would you be so kind to give us your def of "failed"....
Windy, that is exactly my point/question. Everyone says they had their "defective" HB replaced, some say it "failed" and was replaced. But, I would think there would be a quantifiable definition of allowable runout before the part has reached "failure". Up to this point, "wobbling" is the defining term....pretty vague.
IMO and its only my opinion OK, if a part that is supposed to run straight and true starts deflecting from that criteria enough so that's I can visually see it and I ask it to spin at over 6000 RPM's then I have to replace that part whether or not it fails catastrophically or not, I don't care what the definition of failure is, IMHO it has to be replaced. And it was Obviously your car to do with what you want
NSF
Would you be so kind to give us your def of "failed"....
Wobbling so bad I was not sure it would make it to the dealer. The chirp is so loud you have no doubt what it is. You could see the rubber had moved between the hub and the belt drive.
I had my C6 for two days and took it in for belts chirping and a engine vibration at 300 miles. They stated it was caused by " dry rotted " belts and they were replaced.
At 900 miles the vibration continued and the belt failed. This time was told it was a faulty pulley and belt. Again replaced.
I finally looked in to it my self and noted a significant wobble in the HB and took it in at 2k miles. Was told this was normal.
At around 7k miles heard a loud squeal smelled a burning smell and the belt failed. The HB had separated and walked back. New HB, I believe timing case cover, water pump and belts replaced.
Now at 63k miles no issues since.
I check it each time I change the oil and all is good so far.
Your definition of failure is correct, though it is not the "catastrophic" failure I was curious about. One of the objects of my original question is to determine when the appropriate replacement action should occur.
My pulley was wobbling some, and I had it replaced. Others have experience wobble and chirping (which I did not). Still others have never even looked at the piece, or know what it is, and have not replaced anything. Obviously, some/many have a pulley that wobbles, but never fails. Replacing that item is a significant cost, possibly unnecessary. Is the "chirping belt" the definition of failure? I don't know but am curious about it, that's all.
I have replaced mine. But I got my car with 108k on it and the thing wobbled and who knows for how long. I also knew going in that if where was wobble I would replace it first thing. Honestly if it is causing belts to chirp then it is moving too far out of proper alignment. Unchecked the chirping can turn into a failed belt. But that of course is my purely part-time amateur shade tree mechanic opinion. GM is probably the only one that can truly answer the exact run-out tolerances for the part.
Windy, that is exactly my point/question. Everyone says they had their "defective" HB replaced, some say it "failed" and was replaced. But, I would think there would be a quantifiable definition of allowable runout before the part has reached "failure". Up to this point, "wobbling" is the defining term....pretty vague.
Agreed Buck. I think what we may have here is a few people that don't really have that much engine experience rather that what they read here in this forum. Some seem to think that a very slight wobble is a "failed" part. I remember back in the day when I spent most of my time for many years turning wrenches that I saw many balancers. Some of them ran true as Jed Clampet. And some of them had a slight wobble. Back in the day we never even gave a slight wobble a second glance. Don't ever recall one flying apart either, but i'm sure one probably did on a very rare occasion. Now it does appear that some of these LS balancers may have a problem that needs attention, thats fairly obvious. but to think that the part is going to blow apart just because it has a slight wobble shouldn't necessarily mean that it has to happen.......
Dutch, that is a great reply. Thank you for the info. As some have said, their pulley started wobbling prior to 20K, so they had it replaced. In some cases, it wobbled again, and was replaced again (with a factory part, ugh).
Needless to say I did not replace it with a factory part.
I don't mean to hijack this thread, but I'd I like to know if the forum could discuss how to determine when and if the HB needs to be replaced. I think that we can all agree that "failure" has to be more than just a "slight wobble", but when ? I honestly didn't think my HB would fail, but then a loud "bang" about 50 miles from home.
On the other hand, as you say, we shouldn't replace the HB, because of a wobble. Quite correctly IMHO that is not the cause of the "failure". ( Although it might be a symptom when the wobble exceeds a certain amount.) This seems to be a growing problem with age.
Any ideas from anyone ??? When to replace the HB ?
Needless to say I did not replace it with a factory part.
I don't mean to hijack this thread, but I'd I like to know if the forum could discuss how to determine when and if the HB needs to be replaced. I think that we can all agree that "failure" has to be more than just a "slight wobble", but when ? I honestly didn't think my HB would fail, but then a loud "bang" about 50 miles from home.
On the other hand, as you say, we shouldn't replace the HB, because of a wobble. Quite correctly IMHO that is not the cause of the "failure". ( Although it might be a symptom when the wobble exceeds a certain amount.) This seems to be a growing problem with age.
Any ideas from anyone ??? When to replace the HB ?
Probably just a matter of personal choice depending on the experience of the owner. I bought my 06 seven years ago with about 12-k miles. It had about a 32nd of an inch wobble then, and its still the same seven years later. Granted I only put between 2-3-k a year on it, and it doesn't get ran hard on a regular basis but does get wound up from time to time. I marked it so I can keep an eye out for any twisting and/or separation (hopefully...LOL). I'm just gonna let it ride till I see a difference, or until I see it fly through the hood !!!!....LOLOL.....
I marked it so I can keep an eye out for any twisting and/or separation
...
DANG!!! Why didn't I think of that. <quickly I run out and put a white paint stripe on the HB> Thanks
Originally Posted by windyC6
Probably just a matter of personal choice depending on the experience of the owner.
Yes, but this gets us back to the argument of HB replacement being a "cottage industry".
I would like the community to in chime here and offer some concrete advice, if possible, as this problem seems to be getting worse. I like your comment and it might the best way to diagnose the HB, but any comments from the professionals out there would be appreciated. (My apologies, Windy, if you are a professional mechanic)
I guess this could go on and on and on
Why not just say the ole adage "its your car to do with as you wish" if you are happy with the "blank" then great live with it but why try to make it something it isn't.
The "Harmonic Balancer" nomenclature is sort of self explanatory to me. It is not intended to ever "wobble", that in itself is the indication of it starting to fail yet some want to deny it, so there we are, its your car so"""""""""".
We agree to disagree on this one. I'm out
NSF
I guess this could go on and on and on
Why not just say the ole adage "its your car to do with as you wish" if you are happy with the "blank" then great live with it but why try to make it something it isn't.
The "Harmonic Balancer" nomenclature is sort of self explanatory to me. It is not intended to ever "wobble", that in itself is the indication of it starting to fail yet some want to deny it, so there we are, its your car so"""""""""".
We agree to disagree on this one. I'm out
NSF
DANG!!! Why didn't I think of that. <quickly I run out and put a white paint stripe on the HB> Thanks
Yes, but this gets us back to the argument of HB replacement being a "cottage industry".
I would like the community to in chime here and offer some concrete advice, if possible, as this problem seems to be getting worse. I like your comment and it might the best way to diagnose the HB, but any comments from the professionals out there would be appreciated. (My apologies, Windy, if you are a professional mechanic)
OH MY !!! Don't do what I do. Some think it's idiotic to mark it. I just let them have their laugh though. I must admit that it is kinda hard to see if the marks have moved while the engine is running !!........HE HE....
I'm looking at a C6 to purchase. How do you know if the HB is wobbling? And to add to my stupidity...where is it??
If you stand on the passenger side of the car you can see a dial/arrow pointing to an indicator up on top of the engine. This will tell you if it's wobbling down below.
Obviously your car to do with what you want 
that is not the cause of the "failure". ( Although it might be a symptom when the wobble exceeds a certain amount.) This seems to be a growing problem with age.
Yeah me too. 
