Squeak sound from belt

[cashville]

I got a noise on idle, and specially on acceleration that is coming from the belt (i've tried a method which is using a candle wax on the belt, the noise went away for a minute but it came back, so I know for sure it's coming from the belt or some part related)
Before replacing the serpentine belt, I would like to try other methods to see if i can remove the noise, because the belt doesn't seem that worn out. Maybe the noise is coming from the pulleys.. Anyway I can isolate the noise with some tests, so I know the right parts to order?

[Joe]

Had the same problem. Replaced the belts but in end it was the pulley. Try lubricating them first.

[cashville]

Where exactly on the pulleys, should WD40 be used? I'm guessing not where the belt moves, because it's not supposed to get greasy there...

[[__--MUD--__]]

Seriously candle wax? Try a can of brake cleaner next time.

Just put on a new belt. If that doesn't solve it, its most likely your idler tensioner pully.

candle wax...never heard of that one before.

[cashville]

It works to remove the noise, but it's just temporary.
I didn't get a new belt yet, because delivery will take 2 weeks, and I don't want to wait 2 weeks to change the belt, and then find out it was not a belt problem, but rather a pulley.

[[__--MUD--__]]

where are you where its going to take 2 weeks??

if your pulley is ****, your most likely going to need a new belt from it slipping anyway.

There is a spring tool to test the tension on the belt.

Hose the pulleys and belt (both sides) down w/ brake cleaner and see what it does. That will actually clean dirt/grease off.

[cashville]

I'm from Europe, it will have to be shipped here from the USA.
But what I'm going to do, is get my belt out today and find one that matches it, I'd like to go OEM, but it's probably not going to be possible to get it locally.

Thanks for the photo of the repair manual, I actually took a look at it yesterday after making the thread, and it explains very clearly on what should be done to diagnose the problem. I'll try to solve this today if possible...

[guruerror]

Originally Posted by [__--MUD--__]

Seriously candle wax? Try a can of brake cleaner next time.

Just put on a new belt. If that doesn't solve it, its most likely your idler tensioner pully.

candle wax...never heard of that one before.

I remember my grandfather used to have a big stick of waxy material (like a fat candle) that he used to call Dum Dum (or something like that) that you would touch against the belt while it the motor was running and the squeal would go away. I tried to Google it, but must have the name wrong, or it was just a nick name for the product that they used around the shop. He used to work for MACK truck and would bring various kinds of random, industrial-brand products home from time to time.

I've also read of people spraying squeaky belts with Turtle Wax Super Protectant...supposedly works better than candle wax.

[PaHumBug]

I was in the same boat but convinced myself (with the help of a mechanic) that it WAS the idler so I replaced that, but it still squeaked. Replaced both belts and squeak went away. The belts are cheaper to replace so you may as well start there.

[[__--MUD--__]]

Atleast on my vehicles, when ever I have gotten a squeel...it was from the smaller belt that the AC pump was on.

[cashville]

Yeah, I'm going to start with the serpentine belt, since that one is easy, and while at that I will check the pulleys to see if they are stiff in place or if they move a little.
Since the AC belt has to be done from under the truck I will leave that one alone for now, and change the serpentine only. When using the candle on the serpentine belt it went quiet for a minute, so supposedly it won't have to do with the AC Belt, since that one didn't get any candle wax on to get quiet.

[[__--MUD--__]]

Originally Posted by guruerror

I remember my grandfather used to have a big stick of waxy material (like a fat candle) that he used to call Dum Dum (or something like that) that you would touch against the belt while it the motor was running and the squeal would go away. I tried to Google it, but must have the name wrong, or it was just a nick name for the product that they used around the shop. He used to work for MACK truck and would bring various kinds of random, industrial-brand products home from time to time.

I've also read of people spraying squeaky belts with Turtle Wax Super Protectant...supposedly works better than candle wax.

When you say wax...I just think of the friction and heat generated on the belt and pullies. Wax is kinda slippery, its not tacky. I dont get what the hell thats going to do other than goo up the belt. Holding a bar of that against the belt on a running motor is a good was to loose some fingers.

[cashville]

Originally Posted by [__--MUD--__]

When you say wax...I just think of the friction and heat generated on the belt and pullies. Wax is kinda slippery, its not tacky. I dont get what the hell thats going to do other than goo up the belt. Holding a bar of that against the belt on a running motor is a good was to loose some fingers.

It will help to shut up the squeak noise, so you can isolate the problem.
I stuck a pen on the candle so I wouldn't loose any fingers

[guruerror]

Originally Posted by [__--MUD--__]

When you say wax...I just think of the friction and heat generated on the belt and pullies. Wax is kinda slippery, its not tacky. I dont get what the hell thats going to do other than goo up the belt. Holding a bar of that against the belt on a running motor is a good was to loose some fingers.

Yeah...the world is a dangerous place. LOL!

Back in the day there was a bit more room under the hood to reach around...I agree that it may be a little more risky on modern vehicles.

[cashville]

Ok, just removed the belt, and it doesn't show any kind of abnormal wear, it seems to be pretty new, I cleaned it up with a dry rag. I started rolling the pulleys and checking if they moved like they shouldn't, and the alternator pulley when moved around, squeals. I'm guessing the noise is coming from that pulley, it seems pretty identical to the one I was hearing...
Anyone knows what specific alternator bearing fits the H2 alternator, so I can oder it?

[guruerror]

Poke around here if you're looking for OEM numbers: http://parts.nalleygmc.com/default.aspx

[cashville]

I'm going to try to get some bearings for this locally, will post after I have replaced the bearings.

[[__--MUD--__]]

If the bearings are shot, you might as well get the entire thing rebuilt or just put in a new alt.

[PaHumBug]

Just get an aftermarket high output alternator, that's what I did and if I remember it was relatively cheap. Now you have a great excuse for an upgrade!

[pdxrealtor]

Originally Posted by PaHumBug

Just get an aftermarket high output alternator, that's what I did and if I remember it was relatively cheap. Now you have a great excuse for an upgrade!

+1.... bearings in an alternator?? Where's your head man. I can't wait for stuff to break on my truck so I can upgrade!


Bearings,................ on an alternator??

This is all in good fun.... In all seriousness I hope you get it fixed using whatever method is best for you.

PS. wouldn't silicone spray work on the belts.. for testing? Candle wax just seems extreme.