Weird belt squealing problem

[bgood]

Guys, I have a Alt belt that squeals during even moderate engine revs. I thought they only squealed when they were too loose or pulleys were shot.Mine is tight...really tight. And pulleys appear to be good as well. I have used belt dressing as well. The belt is new and drives my water pump with a nonclutched fan and free spinning alternator. The belt is a bit narrow (Bought new a week ago) and fits into the pulley grooves so far that the back of the belt is not exposed beyond the outer edge of the pulleys.

What gives? never had one that wouldn't stop even temporarily with belt dressing.

thanks again, Bill

[68 Stepside]

I don't know if I can help too much, but could it be a bad bearing in the alternator or water pump? Also, you said the belt is "really tight". If it's too tight, you'll kill your alternator bearing because of the sidewards pull on it. Just a few things to ponder, I'd also try a different belt, just to be sure.

Best of luck.

[70short/step]

I replaced my belts a while ago and the parts store gave me those narrow ones too. The didnt squeal before but now with the new ones they do. Dont know if its the narrow or if the cheap material of the belts. But I will go buy new Gates or Brand name one when I get the chance.
70short/step

[walker]

If you ran it with the wrong size (too wide) belt in it chances are that the pulley grooves are worn. It don't take much. Also, if you have A/C and your belt widths are not the same on both your belts then the crank is trying to spin that water pump at two different speeds at the same time, as one belt is riding high on the pully(traveling at X inches per minute) and one is rinding low(traveling at X-Y inches per minute). Hope that is somewhat clear, I couldn't think of a better way to expolain it. Again, it doesn't take much to cause the problem. I would try replacing both belts with the correct width and length belts. Might also try to buff your pulleys out with a scotch brite pad to give them a little tooth, nothing too aggressive.

[GMC AMI]

Hi Bill, I have had a new alt and a new belt and had the same problem at higher rpm's. My belt was a bit wide and I also put belt dressing as well. The new pulley was so smooth you could spin the pulley with belt on and motor turned off. I went to another alt and had no trouble since. This was only my case and it still could be water pump, so Isolate the noise first and you should
be able to correct. Good luck, Mike

[bgood]

I had a feeling the new narrow belt might have been the culprit.. I also am afraid that I may do damage to my alt bearings runnin this tight.
Walker, I understand the concept you are referencing, in my situation the crank has a two sheave pulley that drives my power steering with one belt and drives the water pump and alt with the other. The water pump has two sheaves that runs the a\c compressor off it. It sweals a little if I race the engine(1k rpms or there abouts) But really screams when the a\c clutch is energized so I'm covinced it is the new belt from crank to water pump and the flex fan and a\c pump(new installation) is just too much of a load for the little narrow sucker!. I'm wondering if I may need to go with a cooling fan with a clutch as well.?
I'm going to get a wider belt tomorrow first.

thanks again, Bill

[roger0080]

I have the exact same problem. No A/C. Just alt-water-crank and PS.

New NAPA belt (Gates I believe). Rebuilt Altenator (good bearings), I have replaced the pulley on the altenator from a diffrenent one -- dang thing squels if rev'd, or go over 60 MPH, then eventually over 55 MPH. Not over tightend, yet not slacking belt tension either. Ugh. I never had a problem until I put in a GM plain jane crate engine. Makes me think that it is an alignment problem (ie altenator now too far forward or back).

[68C15]

my guess is the belt is too narrow & sides are not doing the work. the bottom of belt is touching the lower portion of pulley. get a gates or goodyear grom NAPA or CarQuest.

[cheyenne10]

I finally traced one of mine to old clutch fan used on new motor, I see you are not running clutch fan. I replaced it with a spare used one and squeal went away. (this was after new alt. belts and PS pump on trial and error method)!! Cheap fix too after other upgrades.

It sounds like something is dragging on yours too.

let us know what you find.

[Bowtie67]

I just had the same problem on mine, new alternator and belt and would squeel like crazy when you first fire it up. The pulley on the alternator was a chrome unit and I put the old one from the older alternator on and evrything was peachy after that. had tried a couple different belts really tightened up the belt never helped. The pulley was too slippery for the belt to grab it.