Crank Pulley Wobble
Thread Starter
Drifting
Joined: May 2005
Posts: 1,419
Likes: 2
From: "Cedar Valley" (Northeastern) Iowa
Crank Pulley Wobble
Friend just came back from Dealer getting his "air bag" defect fixed (was seat belt retractor) and having them check on a belt "chirp" issue.... They said the crank pulley is wobbling and has to be replaced. I thought this was fixed in 2006.
Does anyone have any information to add?
Thks,
Does anyone have any information to add?
Thks,
Thread Starter
Drifting
Joined: May 2005
Posts: 1,419
Likes: 2
From: "Cedar Valley" (Northeastern) Iowa
Race Director
Joined: Jun 2005
Posts: 10,909
Likes: 2,701
From: Phila Suburbs 2023 C8 & 2013 650ix
Crank pulley wobble can be caused by the center bolt coming loose and that was a problem with the first 11,039 cars in 05. The other problem is the rubber flexible coupling in the "crank pulley" (i.e. harmonic balancer)
becoming deformed. The deformation causes the center hub and outer hub to not be concentric and hence the wobble which causes the main belt to chirp. The only solution is to replace the harmonic balancer at a cost of around $1000 if not under warranty.
becoming deformed. The deformation causes the center hub and outer hub to not be concentric and hence the wobble which causes the main belt to chirp. The only solution is to replace the harmonic balancer at a cost of around $1000 if not under warranty.
Tech Contributor
Joined: May 2008
Posts: 2,843
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From: Howell Michigan
St. Jude Donor '09-'10-'11
Le Mans Master
Joined: Dec 2004
Posts: 5,492
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From: West coast CA
The harmonic balancer can be an issue on any of the LS engines. As Walt pointed out the rubber between the crank part and the pulley part fails causing the pulley part to wabble. There are examples in the C5 tech area that show the extreme failures which can include the front cover to be damaged and even the crankshaft nose. If you see any wabble have it corrected as soon as you can. Hope the dealer gets you fixed up quick.
Race Director
Joined: Jun 2005
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From: Phila Suburbs 2023 C8 & 2013 650ix
Even some brand-new crank pulleys have some visible runout on these engines.
And those are the ones most likely to give you a problem sometime in the future. And GM's poor quality control on this pulley gives them the opportunity to say that wobble is "normal". A good pulley runs true and at idle the ribs of the pulley look like they are stationary.
And those are the ones most likely to give you a problem sometime in the future. And GM's poor quality control on this pulley gives them the opportunity to say that wobble is "normal". A good pulley runs true and at idle the ribs of the pulley look like they are stationary.
Tech Contributor
Joined: May 2008
Posts: 2,843
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From: Howell Michigan
St. Jude Donor '09-'10-'11
Last edited by Eric D; Sep 12, 2009 at 01:07 AM.
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