serpentine belt noise

1998 GMC SIERRA
98,233 MILES • V8 • 4WD • AUTOMATIC
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MELLORIK
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I have an aweful squeeling from the serpentine belt on my truck. It started intermittantly, and has now graduated to 98% of the time. I have replaced the belt, tensioner, waterpump, idler pulley, and alternater. I even tried belt dressing which was probably stupid. I did notice that when it starts squeeling, the voltmeter drops below 10. Help!!!! This is driving me batty. Any ideas????????
Dec 16, 2010 at 9:55 PM
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WRENCHTECH
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Your right, the dressing was stupid. That ruined your new belt and it will have to be changed again. You likely have more than a belt problem. In order for it to slip badly enough for the alternator not to charge, it would have to be very noticeably loose. I would suspect you have a pulley problem in one of the driven components that you will have to look for.
Dec 17, 2010 at 1:06 AM
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MELLORIK
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What kind of pulley problem? Most everything is new, even the tensioner pulley. How tight does the belt need to be? This auto tensioning pulley seems pretty phony to me, I can push the belt in more than an inch with very light finger pressure. Should it be that loose?
Dec 17, 2010 at 7:43 PM
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WRENCHTECH
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If you can push that an inch with light single finger pressure, then something is seriously wrong. You likely have it routed wrong or hae the wrong belt. https://www.2carpros.com/images/external/78221790.gif
Dec 17, 2010 at 9:25 PM
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MELLORIK
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It turns out it was the remanufactured alternater purchased 3 months ago. once up to operating temp, the bearing would seize up. This is what I figured from the begining, but no one would listen. This was the last straw between my family members and this particular parts house(we have an RV dealership, 2 Logging companies, contractors, and 4 different auto racing teams) Of course they won't make good on it because they don't believe this could happen. We have been using them exclusively for more than 40 years. They have new owners for the last 18 months. Oh well, Thanks for your help!!!!!!
Dec 19, 2010 at 5:26 PM
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WRENCHTECH
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What? Since when does any parts store verify failures? If I bring an alternator back and tell them it's defective, the only thing they check is the purchase date. You definitely need a different supplier
Dec 19, 2010 at 6:00 PM