I know the subject of these pulleys has been addressed to death, but I think I have new issue. At least I haven't seen it mentioned before. Last spring I paid a reputable shop in my area to install a new balancer. New pulley, new belts, new bolt. Two weeks ago, I noticed the belts squealing like a stuck pig. I take a look at the new pulley and find that the bolt is not very tight (I could lossen tighten the bolt with an offset 24mm wrench with little effort). I call the shop back and tell them the problem. He takes it for another day and says everything has been checked out and re-tightened and shouldn't have any problems.
When I pull out of the shop, the belts are already squealing again. I thought it was possible due to the heavy rain that we had in the area and thought I would let everything dry out good, before I called him again.

Last night, i finally get a chance to look at it and run a straight edge across the tensioner pulley down to the balancer. I find that the balancer is 8mm off (closer to the engine) than the rest of the pulleys in the belt system. I call the guy again this morning and he says that is impossible, that the crank shaft has a shoulder on it for the pulley to seat against. Does the crank shaft have a shoulder for the pulley to seat against? Is it possible to seat the pulley too far back? When he did this work the first time, there were no problems with the alignment and I wonder what could have changed this time, when he re-tightened everything down.

 

Did they use a new bolt-they are 1 time use bolts.

 

Hi Doug,

They used a new bolt on the inital replacement. I'm not sure about the trip back in last week (I didn't ask) Since the pulley seems to be closer to the engine than it should be and not moving away from the engine, I didn't think it was a matter of the bolt backing out, but I am open to any advice.

This is the first time I have used this shop and they are the only local shop that specializes in sports/muscle cars, so i assumed they would knwo what they are doing. In any case, I sent started this thread to get as much information as possible before I take the car back in early next week.

Thanks,
Tim

 

Tons of threads on the balancer-advanced search is your friend.

 

I find that the balancer is 8mm off (closer to the engine) than the rest of the pulleys in the belt system.

You found your problem, you have failed another balancer.
I'll bet it was a stock replacment, this is one of the few parts I would reccomend to never use a stock one!

 

I had this problem too. The GM harmonic balancers have a tendency to creep towards the engine like that because the outer part breaks off the middle part. If your shop used a new GM balancer then there is a chance of it happening again possibly. I don't know if GM ever updated them not to do that. It's not really the shops fault and if it's been a year since they put it on then I don't think there's really any sort of warranty type thing. You can ask them to ask their supplier but you'd still be paying the labor for them to put a new one one.
I've heard aftermarket ones are better built. At the time mine went bad my shop had a barely used C5 one that I had them put on but I check it every so often to see if it's still in good shape. If it happens again I'll go aftermarket.


Here's a couple photos of what happens:






Good luck!

 

Thanks for the input guys. I didn't look to see if the outer ring was separating from the pulley body and moving. It has only been 6 months, since it was installed, so I didn't even consider that as a possibility. The shop ordered the pulley, belts and bolt from Napa. It looks to be the same basic design as the oem.

I will check it when I get home.

Thanks for the input!