I reported in earlier posts that my belts on my '98 C5 were squeaking. I took it to a friend's shop and he found that the rubber in the harmonic balancer is all worn and wobbling. He said the belts are old and dry too. The job is going to cost $679 total, new belts and all. He said it's a 4 hour job to get the harmonic balancer changed. Does that sound about right?
What gets me is that I just had the car at the dealer and they replaced two tensioners. They said it needed new belts to stop the squeaking. Why didn't they spot the bad harmonic balancer? Can I get away with not replacing it? What happens when one fails?
Seems about right. It's a rats nest of pipes, hoses, belts, and god knows what in front of the LS1, and there's little to no room to get at anything. All the accessories probably have to come off of the front of the motor to access the harmonic balancer, and maybe even the radiator and cooling hoses, can't really tell from the pictures I've found. Regardless, there's a lot to be moved around just to get a hand down to the area of interest.
It's kind of hard to see from the top, maybe easier from the bottom. It's not something that usually fails. Before I'd let them work on it I'd check to see if there's any TSB's out on it. To be quite honest, I smell a rat. I've owned quite a few cars over the years (and most were GM, but not all...) and I've NEVER had a harmonic balancer go bad. Now, I'm not saying that it doesn't happen. It seems to be a common failure on newer Mercedes (went surfing the NG's via Google). Didn't see anything on LS1 HB's, so I doubt it a big failure item. Get a second or third opinion. What happens if it fails completely? As it wobbles it'll chew up the front of the motor including timing chain cover & seal, as well as maybe the lower pulley and serpentine belt. It could conceivably cause timing chain problems and maybe even early crankshaft failure.
He put it up on the lift and showed me. The rubber part in the center of the pully is all cracked and about an inch around the circumference there is no rubber at all that I can see. When the engine is running it is slightly wobbling. And it's in a real tight spot. He showed me on a Taurus how easy it is to get to it. But on the Vette it's inches from the front of what looks like the frame.
I doubt this is the case, it may be loose but no way the rubber is worn in the balancer. Just to let you know the LS1 has an oil filled crankshaft and if the bolt comes loose it will allow a black residue to form. Would have said something earlier but I block spamm.
The belts are old and dry after the first year, it's called flex and heat checking.
There is a new bolt that is used to reseal the crankshaft and lock the balancer back on the crank and as far as I know they don't cost hundred of dollars. More like an $80 fix.
Let me guess, because there isn't one?
The outer ring slips and the engine feels like the block is rotating around the crank.
Same here.
Don't think so but since I've never seen one fail on a car it's a guess at best. My best guess is that you would certainly feel it long before it did that much damage unless it happened on the track at wide open throttle.
Just to help your belief/disbelief in what I said I worked in the tool and machine design department for a tier 1 supplier for harmonic balancers from 1965 to 1968. We tested them to 20,000 RPM unbalanced before we got any failures. That was most always ring separation and not rubber deterioration and the rubber got very hot running like that when unbalanced.
Balancer problems have happened to C5s from time to time. And the C6 as well. It needs to be replaced ASAP. And the upgraded parts should be used. Some like to pin the new balancer since it's still pressed together and can still separate.
Let me know what youthink. Notice the gap, the cracking rubber and the way it's pushed in on oneside and hanging out on the other. If you need pictures with a higherresolution or a movie of it spinning let me know. Should I replace it? If I just replace the belts should the squeaking stop? When I spray belt dressing on the main belt the sqeaking stops for a little while but there's still a sort of rattleling sound.
To quote a regular poster.... As Dad had been suffering much itching and discomfort, moved his belly out of the way, fished around and finally found "Lil Dad", looked down and uttered....
I know what you're saying..but.. I had an annoying squeeky belt on my 2000 C5. Ultimately, it was quited down by replacing the crankshaft pulley. Hard to believe.. but it was "wobbly". Car had about 50K miles on it at the time.
Steve- The pulley is reaplaced from the underneath. The steering rack needs to come out to get at it. Procharger (ATI) has a kit to pin the pulley to the crank. You basically drill a hole in the pin of the crank which goes into the pulley and put a pin in it. In addition to being bolted on with the big bolt which by the way is not supposed to be reused. I'm telling you this because if you ever decide to supercharge your car(highly recommended), your mechanic would have to repeat what he is doing here. Four hours sounds right for the job.
So is the harmonic balancer the same as the crankshaft pulley? I have a photo of what they told me was the harmonic balancer at
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I mentioned replacing the bolt to the Chevy dealer and he said they never replace the bolt. He said it's a huge bolt and is very strong. It seems no one I take it to knows what they're doing. Not even the dealer.
The mechanic at my friend's shop (Midas Muffler) said it is wobbling, but I can't see or feel any vibration or wobbling. I only hear a squeaking and can see that the serpentine belt is chipped on the inside ridges. The Midas mechanic showed me the cracking rubber on the harmonic balancer as proof it was bad. The Chevy dealer said that the rubber gets little cracks in it and dries out within a year and is not symptomatic of a problem. It's the wobbling that is what I should be looking for. I have closeup pictures at
Did you just tighten the bolt to see if it had allowed it to "wobble"? If you note his pictures the bolt head is off center, my guess is that it's loose, not discentagrating. I'm sure replacing a good balancer and tighten the bolt will also correct the problem, but costs more than to tighten the bolt on the old one. Of course I'm still guessing but if I had gone to the trouble of taking the pictures I might have tried to tighten the bolt also. The rubber looked OK, although it did have a bigger than normal gap.
I took the picture by driving up the parking stop. It wasn't up high enough to check the bolt. Just high enough to stich my arm under the car. Great observation though. Thanks. I'll have it retorqued and centered if possible. Seems odd that it's possible that the mounting hole in the flywheel would be large enough to be that far off center?
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