Belt squeak - harmonic balancer?

[CO MJ]

My belt is squeaking with a pretty regular chirp, maybe 200bpm. Seems pretty consistent with the rpm of the actual belt, one chirp per rotation.

I recently replaced my alternator because the pulley nut loosened and wore itself off the shaft. I went ahead and replaced the belt with a new goodyear 102.5" belt. The exact same thing happened with a new alternator, I'm wondering if maybe my belt was too tight. Replaced the alternator again.

I also recently replaced the AC compressor, no problems with the new one yet. I also replace the idler pulley. I do not feel any play in the water pump pulley or the fan pulley.

In the pic below is my harmonic balancer. The rubber ring doesn't look awful, but it is starting to stick out. You can also see a spot where the belt has rubbed against the timing cover, but this may have happened while my alternator pulley was failing. I do not see any movement in any of the pulleys or belt at idle or when given throttle, and there is a good 1/8" between the belt and the timing cover.

 

A mist of windex cures the squeak immediately, which also makes me think it is not the harmonic balancer. I don't really have a way to check alignment of my pulleys, but I also the shaft of my power steering pump is not flush with the pulley, it sits a few mm offset inside the pulley. Can these pulleys shift over time? I can't imagine this moving out of alignment, I had no squeal before the first alternator pulley failure. 

I do not hear any noises that seem out of place with a stethoscope, I'm pretty confident my belt is the right tightness, and tightening further does not alleviate the symptoms. I'm really at a loss as to what to do next aside check pulley alignment, but that's pretty hard to verify if my harmonic balancer is out, and you can't even hold a straight edge on it because of the protruding rubber.

[AZJeff]

It’s hard to tell from your photo, but I think I see cracks in the rubber.  That would suggest a new balancer is in order

[pizzaman09]

I design elastomeric parts for helicopters for a living.  That harmonic balancer doesn't look to hot to me.  Actually is looks a lot more worn out than the one I replaced on my Comanche last week.  I am not sure it's the source of your chirp but it does appear to be worth replacing.  It's not too bad of a job, just rent the harmonic balancer removal and install tool set from your local parts store.  Also don't forget to take the washer off that's under the main bolt, I fought that for 30 minutes...

[CO MJ]

51 minutes ago, pizzaman09 said:

I design elastomeric parts for helicopters for a living.  That harmonic balancer doesn't look to hot to me.  Actually is looks a lot more worn out than the one I replaced on my Comanche last week.  I am not sure it's the source of your chirp but it does appear to be worth replacing.  It's not too bad of a job, just rent the harmonic balancer removal and install tool set from your local parts store.  Also don't forget to take the washer off that's under the main bolt, I fought that for 30 minutes...

 

Agreed, I think that will be a this weekend job. Swapped out an old belt I had, no more squeak. Found a small tear in the newer belt, not sure if that could have caused the squeak or not but all seems to be well now.

[75sv1]

Harmonic balancers are about $50 to $70. Replacing main bearings, well a lot more. Then there's replacing the crankshaft. Also, look at the backside on the harmonic balancer. Was in one thread were the guy's front looked good. He latter said the rear elastomer was real bad. Yes, I've had one go bad. I added it parts to replace on 'new' used vehicles. 

[cruiser54]

[howeitsdone]

[AZJeff]

On 4/21/2023 at 6:20 AM, cruiser54 said:

 

Who is your helper, there, Cruiser?   And did she find the issue using that stethoscope?

[cruiser54]

My granddaughter. She's almost 11 now. Great helper. Even uses power tools.