Harmonic Balancer...Need a Professional opinion!!
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Joined: Dec 2008
Posts: 52
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From: LaCrosse Wisconsin
Harmonic Balancer...Need a Professional opinion!!
My 2000 C5 harmonic balancer has a wobble. I have been told so many different things that I don't know who to believe. A Service Advisor at a
Chevrolet Dealership told me that even the new Vettes have a wobble and that it's normal. Another told me that it should spin true and straight......WHO IS TELLING ME THE TRUTH?!?!? It's a $600.00 repair at the dealership
HELP!!!!!
Chevrolet Dealership told me that even the new Vettes have a wobble and that it's normal. Another told me that it should spin true and straight......WHO IS TELLING ME THE TRUTH?!?!? It's a $600.00 repair at the dealership
HELP!!!!!
Last edited by stunter steve; Jul 30, 2009 at 02:50 PM. Reason: update
Drifting
Joined: Apr 2008
Posts: 1,510
Likes: 15
From: Ga
They are not susposed to wobble. I replaced mine with an SLP and an ARP Bolt. If it's bad, go aftermarket.
My 2000 C5 harmonic balancer has a wobble. I have been told so many different things that I don't know who to believe. A Service Advisor at a
Chevrolet Dealership told me that even the new Vettes have a wobble and that it's normal. Another told me that it should spin true and straight......WHO IS TELLING ME THE TRUTH?!?!? It's a $600.00 repair at the dealership HELP!!!!!
Chevrolet Dealership told me that even the new Vettes have a wobble and that it's normal. Another told me that it should spin true and straight......WHO IS TELLING ME THE TRUTH?!?!? It's a $600.00 repair at the dealership
HELP!!!!!
Burning Brakes
Joined: Aug 2006
Posts: 1,217
Likes: 5
From: Stark County Ohio
It is NOT supposed to wobble. Delaying replacement is at your risk if you decide to delay.
If it is a very, very slight wobble AND you keep an eye on it to see if it gets worse, you may be able to postpone the replacement.
Inspect it weekly. If you even think it’s getting worst, replace it ASAP.
I have read on this forum from a couple of members that the NEW OEM replacement balancer they had installed at the dealership had a very slight wobble. (very slight – whatever they mean by “very slight”).
I would change it with other than the OEM. Many on this site have used the “Powerbond” under-drive pulley and are happy with it. Personally I don’t like an under-drive pulley on a street car. I think Powerbond also makes a factory diameter balancer, but I am not sure. Powerbond is a quality piece and is relatively inexpensive.
OEM balancers are NOT keyed to the crankshaft and rely ONLY on the friction of a press fit to keep from spinning on the crank. Pin the balancer – see below.
You may want to consider pinning the crankshaft to engage the keyway in found in most aftermarket balancers. ATI makes a fixture that is easy to use placing a pin perpendicular to the crankshaft to engage the keyway in the balancer.
-
If it is a very, very slight wobble AND you keep an eye on it to see if it gets worse, you may be able to postpone the replacement.
Inspect it weekly. If you even think it’s getting worst, replace it ASAP.
I have read on this forum from a couple of members that the NEW OEM replacement balancer they had installed at the dealership had a very slight wobble. (very slight – whatever they mean by “very slight”).
I would change it with other than the OEM. Many on this site have used the “Powerbond” under-drive pulley and are happy with it. Personally I don’t like an under-drive pulley on a street car. I think Powerbond also makes a factory diameter balancer, but I am not sure. Powerbond is a quality piece and is relatively inexpensive.
OEM balancers are NOT keyed to the crankshaft and rely ONLY on the friction of a press fit to keep from spinning on the crank. Pin the balancer – see below.
You may want to consider pinning the crankshaft to engage the keyway in found in most aftermarket balancers. ATI makes a fixture that is easy to use placing a pin perpendicular to the crankshaft to engage the keyway in the balancer.
-
Melting Slicks
Joined: Feb 2007
Posts: 3,266
Likes: 8
From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
I'm not a professional but I can tell you my balancer does not wobble and if it showed even the slightest sign I would replace it immediately. I've read a couple threads here on the subject where delay led to completely replacing the engine. It seems the crank and balancer get chewed up and metal spreads throughout.
Former Vendor
Joined: Jan 2007
Posts: 1,584
Likes: 17
From: Lubbock Tx
It should not wobble. It's common enough that some dealers may tell you it's normal, but it's not. Replace it, and you may as well go underdrive while you are at it for a little extra power. If you are uncomfortable with underdrive, we stock not only the 25% u/d powerbond and the stock size powerbond, but in-between those we have in stock a 10% underdrive.
Race Director
Joined: Apr 2009
Posts: 10,581
Likes: 252
From: SE TEX
Shouldn't wobble. BEWARE!!!! If you replace it with an underdrive and you haven't done any mods to your car before it is the start of something that can only be described as 'mod madness'!!!!
Mine started as this, but its so close to the cam so I did that as well. And headers with the LS6 intake. That was just the start. 5 years ago.... Now I have a forged 402, D1 Procharger, A&A fuel system and I still NEED more
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Burning Brakes
Joined: Jul 2004
Posts: 1,172
Likes: 71
From: MA
Like all parts, there are tolerances with balancers. So the question is, what is an acceptable runout? Your dealer is saying yours is within tolerances. I would ask the dealer for documentation regarding acceptable runout and have him measure yours for comparison. Also, if you are looking at it at the edges, it may appear to wobble. Try looking at the ribs when evaluating runout. When a balancer starts to fail, the rubber ring that bonds the rib area to the balancer hub starts to rupture. Run your finger around this to feel if it is starting to rupture.
Melting Slicks
Joined: Apr 2009
Posts: 2,479
Likes: 36
OK.........now you guys have me worried!
How can a harmonic balancer which has a circumferentially bonded rubber section not have a slight wobble to it? I have looked at a minimum of ten C5 Corvettes and every single one had an OEM harmonic balancer with a very slight wobble. Mine included. Every single knowledgeable Corvette owner I spoke to told me that a very slight wobble cannot be avoided because of the rubber. If this is such a serious defect, why is it that no one that I have spoken to, including several GM dealers consider it an issue?
My harmonic balancer when looking at it from the rib area does appear to have a very slight wobble. I have to look at it a very long time before I start to notice. I considered it absolutely normal runout but now I am hearing that any wobble, no matter how slight can lead to catastrophic engine failure.
What do I do now? A GM dealer told me that even if they change it, a brand new OEM balancer may also have a slight wobble.
How can a harmonic balancer which has a circumferentially bonded rubber section not have a slight wobble to it? I have looked at a minimum of ten C5 Corvettes and every single one had an OEM harmonic balancer with a very slight wobble. Mine included. Every single knowledgeable Corvette owner I spoke to told me that a very slight wobble cannot be avoided because of the rubber. If this is such a serious defect, why is it that no one that I have spoken to, including several GM dealers consider it an issue?
My harmonic balancer when looking at it from the rib area does appear to have a very slight wobble. I have to look at it a very long time before I start to notice. I considered it absolutely normal runout but now I am hearing that any wobble, no matter how slight can lead to catastrophic engine failure.
What do I do now? A GM dealer told me that even if they change it, a brand new OEM balancer may also have a slight wobble.
Advanced
Joined: Mar 2008
Posts: 84
Likes: 0
From: Laplace Louisiana
Belt will let u know
I noticed mine wobbling when I bought the car the person I bought it from told me that it was normal so I drove it for about 6 months then it started chewing up belts. I can tell you this, if the belt starts riding out of the tension groove at high rpm's, "dont wait" change it.. I went with a summit under drive, haven't had any problems!
Tech Contributor
Joined: Jan 2007
Posts: 19,471
Likes: 1,171
From: Dyer, IN
OK.........now you guys have me worried!
How can a harmonic balancer which has a circumferentially bonded rubber section not have a slight wobble to it? I have looked at a minimum of ten C5 Corvettes and every single one had an OEM harmonic balancer with a very slight wobble. Mine included. Every single knowledgeable Corvette owner I spoke to told me that a very slight wobble cannot be avoided because of the rubber. If this is such a serious defect, why is it that no one that I have spoken to, including several GM dealers consider it an issue?
My harmonic balancer when looking at it from the rib area does appear to have a very slight wobble. I have to look at it a very long time before I start to notice. I considered it absolutely normal runout but now I am hearing that any wobble, no matter how slight can lead to catastrophic engine failure.
What do I do now? A GM dealer told me that even if they change it, a brand new OEM balancer may also have a slight wobble.
How can a harmonic balancer which has a circumferentially bonded rubber section not have a slight wobble to it? I have looked at a minimum of ten C5 Corvettes and every single one had an OEM harmonic balancer with a very slight wobble. Mine included. Every single knowledgeable Corvette owner I spoke to told me that a very slight wobble cannot be avoided because of the rubber. If this is such a serious defect, why is it that no one that I have spoken to, including several GM dealers consider it an issue?
My harmonic balancer when looking at it from the rib area does appear to have a very slight wobble. I have to look at it a very long time before I start to notice. I considered it absolutely normal runout but now I am hearing that any wobble, no matter how slight can lead to catastrophic engine failure.
What do I do now? A GM dealer told me that even if they change it, a brand new OEM balancer may also have a slight wobble.
Race Director
Joined: Apr 2009
Posts: 10,581
Likes: 252
From: SE TEX
My opinion would be to determine whether it is the rubber that is making it look like it is wobbling or the actual pulley itself. If its just the rubber you should be ok for a while at least but if it is indeed the pulley I would change it ASAP.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
There are TWO different damper failures:
- The bolt backs out and causes the entire damper to walk forward.
- The rubber between the outer damper ring and the hub becomes un-bonded and the outer ring moves forward or aft. If it moves forward, it contacts the rack and damages it. If it moves back it chews thru the timing chain cover and destroys it.
If you see the rubber between the hub and outer ring protruding out in different areas, that isn't good either.
Put some white paint (stripe) on the front of the damper so that it marks the outer ring and hub. If the white paint stripe doesn't line up after driving it you will know that the ring is no longer bonded to the hub.
None of my cars have ever wobbled.
- The bolt backs out and causes the entire damper to walk forward.
- The rubber between the outer damper ring and the hub becomes un-bonded and the outer ring moves forward or aft. If it moves forward, it contacts the rack and damages it. If it moves back it chews thru the timing chain cover and destroys it.
If you see the rubber between the hub and outer ring protruding out in different areas, that isn't good either.
Put some white paint (stripe) on the front of the damper so that it marks the outer ring and hub. If the white paint stripe doesn't line up after driving it you will know that the ring is no longer bonded to the hub.
None of my cars have ever wobbled.
Le Mans Master
Joined: Jan 2007
Posts: 7,364
Likes: 6
From: Rocky Mount Virginia
There are TWO different damper failures:
- The bolt backs out and causes the entire damper to walk forward.
- The rubber between the outer damper ring and the hub becomes un-bonded and the outer ring moves forward or aft. If it moves forward, it contacts the rack and damages it. If it moves back it chews thru the timing chain cover and destroys it.
If you see the rubber between the hub and outer ring protruding out in different areas, that isn't good either.
Put some white paint (stripe) on the front of the damper so that it marks the outer ring and hub. If the white paint stripe doesn't line up after driving it you will know that the ring is no longer bonded to the hub.
None of my cars have ever wobbled.
- The bolt backs out and causes the entire damper to walk forward.
- The rubber between the outer damper ring and the hub becomes un-bonded and the outer ring moves forward or aft. If it moves forward, it contacts the rack and damages it. If it moves back it chews thru the timing chain cover and destroys it.
If you see the rubber between the hub and outer ring protruding out in different areas, that isn't good either.
Put some white paint (stripe) on the front of the damper so that it marks the outer ring and hub. If the white paint stripe doesn't line up after driving it you will know that the ring is no longer bonded to the hub.
None of my cars have ever wobbled.
Former Vendor
Joined: Feb 2007
Posts: 857
Likes: 0
From: DFW Texas
I just had this issue with my C6. The rubber seal that connects the 2-piece HB started to deteriorate.
I would replace it ASAP. Going aftermarket sounds like fun...
Lets us know if you have any questions.
Corvettes of Dallas
I would replace it ASAP. Going aftermarket sounds like fun...
Lets us know if you have any questions.
Corvettes of Dallas
Tech Contributor
Joined: Aug 1999
Posts: 16,376
Likes: 404
From: Should this thoughtful, valuable contribution meet with no acknowledgement or 'thanks' this post----
My 97 had it. During the warranty period I tried to get the dealer to replace it...they said it was normal. At the same time I had the squeaky belt syndrome for years having gone thorough 3 pulleys and belts under warranty. Once it went off warranty I still had the problem with the AC belt now acting up. The solution? New balancer!!!! Bastards; cost me $700 to replace it despite the fact I complained about it from day one....
