Alternator belts squeeling

[2deuce]

I've read alot about this subject, but I can't seem to stop the belt squeeling. I've put on new belts. Gotten them very tight, tight to the point of worrying about alt bearing failure. The squeeling will stop for a few starts, but comes right back and the belts are still very tight. I seem to be just stretching the belts. After the alternators come off of the high demand at start up the squeeling stops so I don't have it all the time. I'm wondering if I shouldn't rough up the alt pulleys with sandpaper or something since they are so smooth. Think that might work? or is there anything else that should be done?

Thanks

 

[Westech]

That what I would do.. sand the pulleys on both the engine and the alts. clean them up good and that should take care of your problem.

 

[jw4x4]

This works, too. Put some household cleanser (powder form such as Comet or Ajax) on the belts. I have done it VERY CAUTIOUSLY with the engine running. Put the cleanser in a baggie, trim off one of the corners. Be aware of where the fan is blowing so you don't get a face full. Let the cleanser pour out of the baggie onto the backside of the belts. It doesn't take very much. The squeeling will go away.

 

[Lawrence of Arabia]

Don't want to be Mr. Obvious but be absolutely sure you have good belt alignment. I just went through this and pulled my hair out. I had all the stock mounting hardware and the right alt. was still way off. Finally a mechanic buddy of mine put a little larger spacer between the alt. pulley and fan. This brought the pulley out and now no belt squealing.

 

[Armada]

Also make sure your alternators are properly aligned. If not, they will accelerate the wear on the belt by sideloading them. You may be missing a spacer on the mount or a bent bracket or something similar. Pic below shows a spacer missing. This caused the alternator to mis-align and create a belt squeal, even with a new belt installed.
The belts must also be tight. A new belt may be tight at first, but it will stretch after a short time and will need to be retightened. Usually the second tightening will be enough.

 

[Armada]

You beat me to it blckdblnckl! lol

 

[Ken_86gt]

One more thing to check, loosen all of the belts and check that everything rotates easily and smoothly by hand.

 

[2deuce]

Thanks to you all of you for the suggestions. I'm not missing the spacer and the belt looks aligned. I will try sanding. I stretched one belt completely out by tightening it over and over until it ran out of adjustment. The right side belt doesn't make as much contact with the pulley making it easier to slip. Thats the problem one.

Thanks again

 

[319]

The right side belt doesn't make as much contact with the pulley making it easier to slip. Thats the problem one.

Thanks again

Could have the wrong pulley on it.

 

[davo727]

One other thing that can squeal is if the sheet metal guard under the top radiator hose is hanging down a little the top of the left belt will come up and hit it and squeal. Just bend it up some out of the way.

 

[motormayhem]

One other thing that can squeal is if the sheet metal guard under the top radiator hose is hanging down a little the top of the left belt will come up and hit it and squeal. Just bend it up some out of the way.

Do you have a picture of this guard? What is it for?

 

[davo727]

It keeps the belt from rubbing a hole in the underside of the upper radiator hose.

 

[motormayhem]

It keeps the belt from rubbing a hole in the underside of the upper radiator hose.

Hmmm so that's whats missing on my truck and why I need a new radiator hose. Time to make one.

Thanks,
Miles

 

[davo727]

I will take a pic tomorrow and post it

 

[Milkman357]

I have same thing happening....

At start up, the heavy load seems to cause slipping. I was going to wait awhile and try Goodyear Gatorback belts...... I've had great luck with those belts in the past.

Great thread.....Now I can look at other issues too...

My M-1009 is pretty new to me..... So I kinda wondered if this was just a problem from vehicle sitting for a year before I rescued it. I have noticed the slipping is intermittent now....not at every start up anyway.

 

[john ford]

I have a similar problem, but my pulleys ( 3020-01-147-7935, 14067720, 15599204 ) need replacing and have been discontinued. I hesitate to order something like a 3 1/2" OD pulley with a 5/8 or 7/8 shaft, because the measurements are just off.

Anybody have 2 of these pulleys or any clues as to where I can find them? I'm trying to track down some businesses that have ordered them off those NSN lookup sites, but so far I've only found one place selling them for $95 each(!!).

 

[2deuce]

It appears that the passenger side alt pulley doesn't make quite as much contact with the belt as the left side, its a shorter belt on the right if I remember right. I did some sanding and it did help. I hope it lasts, if not I'll try sanding some more and get some cleaner on it too. One friend said to put some brake fluid on the belt that it softens them up so they grip. Also not to waste your money on those belt ease spray applications. I would like to see the pictures of the guard. I don't have it.

Thanks

 

[max1008]

Same problem here, Mine started squeeling constantly. I messed with tension with no avail. I pulled the plug on the alt and it instantly stopped squeeling. When i plug back in it starts up again. Im guessing that something inside is squeeling when the alt is energized. I guess its time for a rebuild?

 

[corelokt]

I used the gatorback belts and it did cure the issue.

 

[tankie88]

Mine does the same as soon as there is no load on the altenator it stops squealing.But it's only started since the onset of colder weather.Hmmmm.