Harmonic balancer failure
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 46
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From: Houston Tx
Harmonic balancer failure
Noticed a small oil leak on my 2006 and started looking for the culprit. I was very surprised to find that the outside ring with the assesory belt and AC belt drive had slipped back to the block approximately 1/2 inch and has cut something (haven't gotten it apart yet) that has caused the oil leak. The photos aren't great, but you can see the pulley up against the block and the belts riding on the edge do the pulleys.
I have done some looking on the Forum and elsewhere and am probably going to do the repair myself even though it is pretty involved.
Thoughts on after market balances? I notice that GM has discontinued their unit.
Anybody ever seem this type of failure?
Thoughts on what the pulley cut to cause my oil leak?
I have done some looking on the Forum and elsewhere and am probably going to do the repair myself even though it is pretty involved.
Thoughts on after market balances? I notice that GM has discontinued their unit.
Anybody ever seem this type of failure?
Thoughts on what the pulley cut to cause my oil leak?
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
I think everyone has seen that failure... very common
You can either go high end, i.e. IW / ATI for a new balancer or cheaper and use part number C2501 from summit. I think powerbond has some options too but I've heard they are back ordered quite a ways
I did the C2501 a year and a half ago and it's been fine, even with a supercharger. You'll have to replace the front timing cover seal and maybe even the front timing cover depending on whether the balancer wore into the cover.
Obviously don't run it anymore like that. The AC belt came off on mine and managed to break the AC clutch connector in the process, so I had to replace the AC clutch too, which was a royal pain. Hopefully yours just needs a new balancer/seal.
You can either go high end, i.e. IW / ATI for a new balancer or cheaper and use part number C2501 from summit. I think powerbond has some options too but I've heard they are back ordered quite a ways
I did the C2501 a year and a half ago and it's been fine, even with a supercharger. You'll have to replace the front timing cover seal and maybe even the front timing cover depending on whether the balancer wore into the cover.
Obviously don't run it anymore like that. The AC belt came off on mine and managed to break the AC clutch connector in the process, so I had to replace the AC clutch too, which was a royal pain. Hopefully yours just needs a new balancer/seal.
Last edited by schpenxel; Apr 5, 2016 at 01:07 PM.
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 46
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From: Houston Tx
Thanks for the feedback. I was thinking ATI, but I bet when I compare prices, I'll be looking at the Summit unit. I would think that any reputable after market would be better than came on the car.
Safety Car
Joined: Jul 2009
Posts: 3,755
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From: Baton Rouge LA
St. Jude Donor '14, '16
Racer
Joined: May 2010
Posts: 277
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From: MO
Ive owned two vettes and had to replace the balancers on both. Did the first vette myself and paid a shop to have the 2nd done. Went with ATI ones and never looked back. Anyone that hasnt seen this failure, hasnt drove the vehicle as it was designed 
Last edited by Spoolin8; Apr 5, 2016 at 02:30 PM.
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 46
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From: Houston Tx
Just ordered the Summit unit, installation tool and bolt. My car has 152000 miles which sounds like a lot on the original h-balancer. I noticed the slight wobble, but Chevrolet says "don't worry about it". Wished I had fixed it before it rubbed a hole in my timing chain cover.
Safety Car
Joined: Aug 2005
Posts: 4,279
Likes: 82
From: North Strand, NMB, SC; Retired x 2 (US Army: 70-90 AD) (US Army: 91-16 DAC); yea, I'm old.
I just replaced the balancer on my '05 after 141,000 miles...I had my dealer do the work since I get 12 months and unlimited mileage on the part; if it fails, the dealer picks up the check.
I have put 2,200 miles on it since the work was done and my road trips left for this year will total somewhere in the neighborhood of 8,000 miles. If it takes another 140,000 miles before it needs replacement, I can live with that...
I have put 2,200 miles on it since the work was done and my road trips left for this year will total somewhere in the neighborhood of 8,000 miles. If it takes another 140,000 miles before it needs replacement, I can live with that...
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Racer
Joined: Feb 2016
Posts: 472
Likes: 39
From: St. Louis Missouri
Had mine replaced at 72,000 with the ATI. Put another 2k on it since and everything seems to be working out fine. I had a mechanic neighbor tell me to go with the ATI. He said they make the best so I took his word for it.
Le Mans Master
Joined: Oct 2008
Posts: 8,891
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From: Whitby Ont.
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
It's a coin toss IMO. Chain/gear looked fine on mine at similar mileage. Oil pressure didn't change significantly with a new pump (used a stock volume/stock relief spring though so that's at least partially why)
Instructor
Joined: Mar 2016
Posts: 118
Likes: 14
From: Honolulu HI
I just replaced the balancer on my '05 after 141,000 miles...I had my dealer do the work since I get 12 months and unlimited mileage on the part; if it fails, the dealer picks up the check.
I have put 2,200 miles on it since the work was done and my road trips left for this year will total somewhere in the neighborhood of 8,000 miles. If it takes another 140,000 miles before it needs replacement, I can live with that...
I have put 2,200 miles on it since the work was done and my road trips left for this year will total somewhere in the neighborhood of 8,000 miles. If it takes another 140,000 miles before it needs replacement, I can live with that...
Instructor
Joined: Mar 2016
Posts: 118
Likes: 14
From: Honolulu HI
are there any noticeable performance symptoms the car may have before the harmonic balancer fails? most of you guys seem to have the problem 100k+ miles but jus saw a comment about it failing at 4k miles as well. my car has 71k miles, anything to worry about? or does it jus happen randomly lol.
Le Mans Master
Joined: Oct 2008
Posts: 8,891
Likes: 981
From: Whitby Ont.
are there any noticeable performance symptoms the car may have before the harmonic balancer fails? most of you guys seem to have the problem 100k+ miles but jus saw a comment about it failing at 4k miles as well. my car has 71k miles, anything to worry about? or does it jus happen randomly lol.
IMO, the h/b failure is blown way out of proportion, same as LS7 heads, just over hyped, sure it happens, so do flat tires and squeaky roofs and hvac. don t worry about it, check it every 5 yrs and drive it and enjoy.
Last edited by walleyejack; Apr 6, 2016 at 08:19 AM.
Racer
Joined: Feb 2016
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From: St. Louis Missouri
