Loud Noise Under Hood may be Loose Alternator Pulley Bolt

[ALF1]

At 210,000 miles on my 2003 XC90 2.5T AWD, I noticed a slowly growing noise / growl under the hood that I just could not identify. Eventually it became loud but unidentifiable. After a 600 mile trip it got very loud but nothing seemed amiss. Serpentine looked fine. Low mileage on the timing belt. Finally, while watched the engine run, I noticed that the pulley on the alternator shaft was occassionaly drifting axially in and out almost a half inch. I didn't realize that the pulley is bolted onto the shaft because the end of the pulley is covered with a thin black plastic cover and appears to be pressed on. I nursed the car home...too late...the pulley fell off as did the serpentine belt. Drove on battery until it went dead and then a tow. On inspection, I noticed that the end of the alternator shaft is threaded inside and out. The outside threads had been ground off....obviously the source of the loud noise. Yes, I replaced it with a reman alternator that came with an installed pulley. I also replaced the serpentine belt as it experienced grind points when the pulley came off. All is fine. No more loud noise, no more growl.

[cuhfs]

good info thanks!