Harmonic Balancer Wobble

Tech discussions on the L77 6.0L V8.
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yargnits
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Harmonic Balancer Wobble

Post by yargnits »

I popped the hood today to show a friend the engine in my Caprice and noticed the harmonic balancer/lower pulley has a substantial wobble to it. I went to a nearby GM service center and had them look at it. They told me that it wasn't considered a repair under the drive-train warranty because it being a pulley, means its an accessory. :shock: I said it was not just a pulley and that the engine would not run (correctly) without it. He said I could take should take it up with Chevy. I didn't have time to move up the chain of command today so that's a battle for another day.

My questions to you guys is; Do you think a wobbling harmonic balancer should be covered under the drive-train warranty?

See the video of my balancer here: https://youtu.be/RWVFn5j61bs" onclick="window.open(this.href);return false;
Dave B - Yargnits
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smwalker
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Re: Harmonic Balancer Wobble

Post by smwalker »

THe way it has always been explained to me is powertrain is components inside the block/case. Everything external not covered. To me though a harmonic balancer if far from an "accessory" as it is integral to the operation of the engine.

That being said if they refuse it so be it as that gives you an opportunity to get a aftermarket unit that is far superior to the stock ones that have a pretty high failure rate from what i read on the G8 boards.

I feel a pretty good wobble in mine at a certain idle but mine does not look as bad as yours.
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
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yargnits
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Re: Harmonic Balancer Wobble

Post by yargnits »

I've been out of town these last couple days and I'm going to talk to the dealer and have them replace it IF it's under warranty. I think it should be covered after reading the G8 board. If they refuse I'll look into replacing it myself. I'm not sure it there's enough room to make it easy. I see SLP has an underdrive balancer/pully for the G8. I wonder if it will fit our cars and is it really worth it. Otherwise Summit lists a few units for our cars.
Dave B - Yargnits
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elc32955
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Re: Harmonic Balancer Wobble

Post by elc32955 »

There was a tech services bulletin for bad harmonic balancers both on the G8 and the Caprice. Mine was replaced under warranty. If your dealer refuses to replace it under the warranty, tell him that this is a known defect on these cars, it's been covered under warranty in the past, and request they escalate this to the zone office. Also make sure to tell them if they do not honor their powertrain warranty that a complaint will be filed with GM by you in light of this TSB. Do NOT put up with the dealer's BS on this for a second. Here's the TSB text...
#PIP4750E: Belt Squeak Noise And/Or Crankshaft Balancer Appears To Wobble - (Feb 10, 2012)

This PI was superseded to update recommended field. Please discard PIP4750D.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern: Some customers may complain of a belt squeak noise and/or a crankshaft balancer appears to be out of
balance or wobbling while watching it with the engine running. In most cases, the wobble is an optical
illusion because the design of the balancer gives the appearance that it is moving more than it actually is.

Recommendation/Instructions: If this concern is experienced, follow the steps below:
Notice - An inaccurate reading may be obtained by measuring the face of the balancer instead of the rear of
the drive belt groove. Please follow this diagnostic or repair process thoroughly and complete each step. If the condition
exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Subject: Belt Squeak Noise and/or Crankshaft Balancer Appears to Wobble
Models: 2010-2012 Chevrolet Camaro SS
2011-2012 Chevrolet Caprice
2009-2012 Chevrolet Corvette
2008-2009 Pontiac G8
with 6.0L 6.2L Engine (RPOs L76 L77 L99, LS3, or LS7)
1. Push the crankshaft all the way to the rear of the engine.
2. Using a magnetic base, attach a dial indicator so the measuring tip is contacting the rear of the
drive belt groove.
3. Rotate the crankshaft 360 degrees and note the total amount of crankshaft balancer run out.
• If the balancer run out is 0.40mm (0.0157”) or less, do not replace the balancer because the run
out is in specification.
• If the balancer run out is greater than 0.40mm, replace the crankshaft balancer and perform step
3 again to confirm that the run out of the new balancer is in specification.
4. If the customer has complained of a belt squeak, also replace the drive belt.
Good luck!
Eric
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
Navy Lifer
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Re: Harmonic Balancer Wobble

Post by Navy Lifer »

In the dealer service & parts organization, GM document ID for this bulletin is 2762265.

If a dealer can't or won't acknowledge the problem--just tell them to look it up using that number.
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yargnits
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Re: Harmonic Balancer Wobble

Post by yargnits »

I have an appointment on Wednesday. I hope they have the part in stock so I get it back right away. I'm willing to pay for a decent replacement if they'd let me, but they'll still with the GM part that will probably go bad in a few hundred miles.
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Re: Harmonic Balancer Wobble

Post by CrashTestDummy »

Yep, that's the dilemma. Do you have them replace it, and who knows what else they'll mess up, with something that might still fail later on, or do you try it on your own, with a nice, but not cheap, SFI-compliant under drive balancer/pulley?
Gene Beaird,
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elc32955
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Re: Harmonic Balancer Wobble

Post by elc32955 »

Well, most service departments can at least change the tensioner pulley without getting things too bad off. Mine was changed at around 11,000 miles by the local dealer about 3 1/2 years ago. I just hit 75K the other day and the revised part is doing fine, no issues.
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
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yargnits
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Re: Harmonic Balancer Wobble

Post by yargnits »

That's encouraging news. My car is just at 10k now. Maybe it's just a bad original part and the replacement will last.

Now that I'm back home, I gave it a closer look and there is some room in there to work. I'll still let the dealer have a shot at it.

In seeing the video, would you guys keep driving it until it heads to the dealer?
Dave B - Yargnits
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elc32955
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Re: Harmonic Balancer Wobble

Post by elc32955 »

Mine was at least that bad if not worse. I wouldn't AutoX or track it like that, but routine stop-n-go shouldn't be a problem for a few days I would think. Final decision is yours though :)
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
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