Well its loose so if you or someone else has the tools, need to figure out which is loose and snug it up or perhaps the belt is going bad? - again check.
but in the meantime you can take a bath soap bar and VERY CAREFULLY rub some on the inside of the belt, this will stop the squeal short term. Luck.
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2001 Limited 4WD - 346+K - SunfireRed\Thunder Cloud; - 265/75/16 Michelin A/T2s - Fat Pat's 1.5" BL - StopTech ANGLED rotors - In series 699 trans cooler, New Yota1 transmission, All new OEM suspension front to rear.