2000 MAX belt screech adj screw lossening w/driving

[Ddaggwood]

Hi, I'm getting a screeching sound from my belt after a alternator change. After I adjusted the tension screw on top of the pulley the noise stops. 15 / 20 after driving, noise again. When I check the adjustment screw it seems to have loosed and the noise is back. Changed the pulley first, didn't help. It seems the screw is coming loose while driving. Any idea?

[maxhopper]

Once you adjust the tensioner you have to tighten the nut on the pulley.

[Ddaggwood]

Thanks. Sometimes you just need to slow down. I know this, but was just over thinking it. Actually it seems when I replaced the pulley, I put the spacer behind the adjuster instead of in front of it. It kept the pulley from locking into place. Thanks again for your imput.