SpinMonster

I had a C6 come into my friend's shop that has a slight wobble to the balancer. Its brand new. It makes no vibration, no noise from the belt, and runs perfect. Its a fraction of a mm of a wobble. Barely detectable.

For reference, I looked at my 2005, it has the exact same wobble, no issues. I looked at my hummer (LS engine in there too) and it had a worse wobble although still barely detectable. My Hummer has silky smooth revs and is not modded in any way. There is no vibration in the driver's seat nor when I put my hand on top of the engine with someone revving it.

Did anyone else have this issue? I've read about dampers failing with the rubber separating from the metal but other than belt squeal, there isnt a vibration.

I've seen two C5's this week and both have that exact same wobble none had a vibration. Is it a GM normal?

5 cars with a wobble and no belt noise or vibration cant all have bad harmonic balancers.

Did anyone have this issue and did you have a vibration or belt noise?

redls3

i looked at mine the other day and noticed a slight wobble also, ihave an 08 ls3.

im swapping for the Ati pulley next week

pinebluffhand

I made a post about mine before I read yours. My 05 is wobbling pretty good but runs smooth with no issues. But I think I will replace it just to feel better about it

Walt White Coupe

As noted, slight wobble is very common. It only becomes a problem when it causes your belt to chirp. You will never feel a vibration because of the wobble.

torquetube

As far as I can tell, _everyone_ has this issue.

My original one wobbled a little, then after a while it wobbled a lot, so I replaced it. The new one wobbles a little.

What would be helpful is an official run-out specification so we could stop using words like "a little" and "a lot."

Maybe you could put a test indicator on your collection of LS2s and we could start compiling a run-out database.

REVAK

My 06 C6 , slight wobble, approx. .025" - .035". No noise or problems.
01 LS1 , no wobble, 98 LS1 ,no wobble. Seems to be more common in the later LS engines . Not sure what year it started to occur.

marc8090

It is very common, but not ALL have it. My mom's 09 wobbles, my 08 appears to have absolutely zero runout while spinning.

Speedforhire

I had an issue with my 2010 base coupe. Here's the GM TSB#2489214...........(from my service receipt).........after the third visit. I could not locate any info on the net related to the number.

QCVette

It is pretty common in the C5's too.

I had one fail (wobble and chirping) at only 30k miles. I replaced it with a Powerbond and no wobble at all.

SpinMonster

I checked two C5s and both had it.

I know UD pullies like a powerbond dont have the wobble but are they acting as a vibration dampener? The GM use of the two piece with rubber is to absorb vibration. A solid unit without rubber is just a weight. I know nothing of the science behind it but since I havent seen a car without the wobble, I am led to believe that its a byproduct of the design. I know they fail making noise but I was more concerned with bearing damage if they dont do their job of absorbing vibration. I can see an out of balance engine running a solid pulley having more issues.

One thing to keep in mind is that GM considers our engines to be balanced if they are +/-70grams which is rediculous. Unless I have an aftermarket forged motor that is properly balanced, I wont run a solid pulley. I think high rpm use would be best served with a $435 ATI superdamper as opposed to a 250 dollar solid piece.

Thanks everyone for posting. Manners and pooling the experience base is what makes this forum the best around.

QCVette

I put a Powerbond on mine, but not the underdrive one. I used the standard size. It is not a solid piece. It has an "rubber" section to help absorb torsional vibration just like the OEM one.

CWHPARTS

Very common problem we replace 3 or 4 dampners each month c5 and c6 ls3 dosnt seem to be as bad as ls1 or ls2

DrivnXcitment

73,000 miles on my 05 Z51, and it has had a wobble the whole time. Glad to hear that it seems to be normal. Note: I have had 0 issues with my engine. I have had her since new.

djdngdoug

My belt began chirping today. Should I replace the damper immediately? Thanks.

djdngdoug

Seems most people agree ATI is the way to go on this. Does anyone know the part number and where to get it? thanks!

phylrick

I replaced the balancer with a SLP 05-06 C6 HARMONIC BALANCER/UNDERDRIVE PULLEY Part No. SLP-100225. Cleaned faces carefully and ended up with .001" runout.

Got mine from http://www.lethalperformance.com/.....cost $211

djdngdoug

Thanks for the info!

berk4422

I had a friend with the same problem look at mine, he said it was fine. You probably got a lemon, you should sell it and should buy a BMW Z.

ed_judo

Replaced mine at 55k, started making noise and it was wobbling. No wobble at all and noise is gone.

good luck!






s/c C6 A&A kit

djdngdoug

HAHA! Gee, wonder who that friend was! You are a nut!