One in the family, same year, same problem. I don't know the answer to the
problem but your car isn't unique.

Sounds to me like you're correct... about the alignment problem... but
you failed to mention if you had checked that yourself ... and ruled
that out.

Professor
www.telstar-electronics.com

call Nemet Motors in Jamaica queens 1800 nemet ny
they have a great guy i talk to all the time about
how to fix stuff on my own without waiting on line
i give him a lot of business
call Wayne At Nemet Motors

I have had this problem before with other cars and trucks.

It is important that there are no alignment problems, and or the belt is
actualy worn or damaged. Make sure that there is no binding, or
resistance to turn. If there is too much resistance, the belt may be
slipping. Make sure that any bushings, and or bearings associated with
the pullies are defective. If so, replace anything that is defective.
Past this point, read another fix below.

It is possible that over the years, the belts have slightly worn down
the inside surface of the pullies. Now that they seat exactly to the
shape of the belt, and have no roughness in their surface in relation to
the belt, they will start polishing or glazing the belt surface. When
the mating of the two surface are exact, they can form a resonance
together, and the squealing will start. It sometimes can be worse on
humid or rainy days.

Remove the belt, and take some medium grade crocus cloth and sand the
inside of the pullies (pulley track) to take the shine out. After the
you finish sanding, make sure that the surfaces are clean by cleaning it
with some washer fluid, and a cloth.

It would be best to put in a new belt, but if you want to live with the
slightly glazed one, it may work okay. The glazed belt may polish the
surfaces back more quickly than a new one. For the cost of a belt, I
would put in a new one.

Mount the belt back to the proper tension. Start the motor. While the
motor is running, take a bar of Ivory soap (Ivory for some reason works
the best), and run it along the surface of the belt. Be extremely
careful that the bar does not get grabbed, and pull your hand with it!
This will put some residue on the belt, to act as a sort of dry
lubricant.

Does anybody out there have a 2005 Sentra 1.8liter that has loud squeaky
alternator belts?  I have one that I bought new 1 year ago that now has
25,000mi and squeaks like the belts are loose all the time.  The belts
are
at the proper tension.  I checked them. Took it to the shop and the
moronic
mechanic said that the belt was old and glazed.  (The car had a new
belt) I
told him that if the pullies are in line and running true, it shouldn't
make
noise anyway. - no friction-no noise!  Just a law of physics.

Anybody had the same problem?