Bad alternator bearings

[edgephoto]

That doesn't sound like a bearing noise. I have seen the ring spin on harmonic balancer causing a belt squeal noise.

Original alternator and replacement make the exact same noise......chances are extremely small but not zero. I would look for another cause.

 

[bucket]

If this is the case, get a TuffStuff or Mechman alternator. Both made in the USA. I have both and they have both been great. Very good output at idle.

Or have one rebuilt by a local shop. Or semi-local... I know not every city has any rebuilders left.

 

[bucket]

With mine the tighter I put the belt, the more noise I had. Again, I had spent extra for the AC Delco and still got garbage. It lasted about 2.5 years and less than 5K before the noise became unbearable.

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My bearings were never rough. There was just lateral play and it was there when I first installed the alternator. No lateral movement in the new one from O'Reilly's.

I've got many many rebuilt alternators over the years and there's been crappy ones from pretty much every store. It's not a recent issue either, they've been iffy for at least 25 years.

On the first one bearing had noticble play and the pilot bolt got hit enough to burn me.

The second one felt smooth but I could see wobble in the fan

3rd one. I didn’t investigate much last the super loud noise.

The alternators all say ac del o on the case but came in plain cardboard box. At the end of the day my suspicion is a lot of this stuff all flows from the same sources.
I’d gladly pay more for a part that will last.

The last few years, I've mostly only bought the AC-Delco branded alternators. So far, they have been fine.

However iirc, they've all come in boxes that say AC-Delco all over them.

 

[idahovette]

Local rebuilders are the only way to go imo, you have someone local to yell at, plus they will almost always fix it.

 

[Memaloose]

Alternators are pretty easy to rebuild yourself. Get a manual for test specs, order your parts and reassemble, that way you know it's good.

 

[Sad Sack]

First thing to usually do on a squeal situation is to remove the belt, start vehicle. No squeal sound, your troubleshooting just got a heck of a lot easier.

 

[Grit dog]

I've got many many rebuilt alternators over the years and there's been crappy ones from pretty much every store. It's not a recent issue either, they've been iffy for at least 25 years.



The last few years, I've mostly only bought the AC-Delco branded alternators. So far, they have been fine.

However iirc, they've all come in boxes that say AC-Delco all over them.

I hadn’t replaced an alternator/starter etc in the last 25-30 years on anything until a couple in the last 5 years.
I got 3 bad alternators in a row, out of the box, from Napa a few years ago.
Next one that went out was different vehicle but original low miles. I opted to have that one rebuilt locally.
Did a little research on reman alternators after that 3 in a row incident and learned that most remans basically fix only the part that wore out in the core and not “everything”.
slightly off topic but the one I had rebuilt was for 06 Mustang. If not for the internet I may have never solved the issue. It charged fine but the car was throwing cam sensor codes and randomly running like ****. After replacing both cam sensors at different times, I learned that a bad diode in the rectifier causes a weird signal that presents as a cam sensor fault to the ECM! Whoda thunk it? Bad Alternator causing random misfires….indirectly.

 

[edgephoto]

You can take the alternator to one of the big box parts stores. They have testers that spin the alternator and check for output. In your case have them spin it. If it squeals you know you found the culprit, if it doesn't move onto something else.

My money is on something else. Bearings usually make a growling noise not a squeal.

These GM alternators are stupid simple. You can rebuild it yourself. Lots of YouTube videos on how to do it. Just hunt down good quality parts.

Where in MA are you? If not too far, I am glad to come by and give a hand.

 

[newguy11]

Those of you pointing out that the alternator is likely not the cause are correct.

I Put a $10 Facebook alt on and I still had the same problem. There is no way. The alt is the problem.

Alt belt appears new, it’s only 18 months old.

Removed all belts except alt belt and i still hear the squeal.

Belts rides nice in the alt pulley but may be low in the crank pulley ( 3 groove pulley)

Crank pulley bolts are all tight and there is no play in the pulley…

I’ll get to the bottom of this, it’s just a head scratcher at the moment

 

[newguy11]

First thing to usually do on a squeal situation is to remove the belt, start vehicle. No squeal sound, your troubleshooting just got a heck of a lot easier.

Belt removed : noise gone

Belt on with any degree of tightness squeals like a pig..

Take a look at these pic, anyone think the belt is riding to low in the groove?

This is the belt as it sits on the crank pulley.

The pulley without belt ( although rides in groove furthest from block

Belt as it rides over the fan pulley

 

[AuroraGirl]

Belt removed : noise gone

Belt on with any degree of tightness squeals like a pig..

Take a look at these pic, anyone think the belt is riding to low in the groove?

This is the belt as it sits on the crank pulley.

The pulley without belt ( although rides in groove furthest from block

Belt as it rides over the fan pulley

your pulley groove might be getting worn

 

[SquareRoot]

your pulley groove might be getting worn

.....

 

[AuroraGirl]

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[newguy11]

your pulley groove might be getting worn

Okay I can see this being a possibility.

Is this a fire the parts cannon situation? Grab a new pulley and belt and pray?

 

[AuroraGirl]

Okay I can see this being a possibility.

Is this a fire the parts cannon situation? Grab a new pulley and belt and pray?

no, get some more up close pictures of the pulley , maybe put a bit of white paint on the the thing with a paint marker so its contrasted