You guys have been a great help with things. So here's another: suddenly the belt squeals loudly when I start it (1988 w/302 F250 4wd manual trans). It settles down to quietness after running for a little. I guess that means the serpentine belt needs replacing? I''ve read the service manual and it doesn't look that bad but what say you ? are there any special words to yell when doing it?

 

In my experience that means it's loose. A new belt might fix it, but I'd be looking at the tensioner.

 

Spray water on the belt. If it's misalignment, it will go away for a few minutes. If it's the belt tension, it will get louder.

 

The belt appears tight, and according to shop manual has an auto tensioner. Another posibility is the sound is the bearing in the tensioner? Are parts available?

 

You need to replace the belt ... And Deglaze all the pulleys.

Once they squeal they polish the pulleys ... then slip, causing squeal.

Just replacing the belt will cause it to squeal shortly.

Pull the belt, Test all rotating elements for smooth quite operation especially the tensioner pulley, Use Fine Scotch pad to THOROUGHLY remove the glaze from all pulleys to the depth of the grooves ... Clean each pulley with brake kleen or the like, install new belt.

If you do it right, the squeal will be gone, if not it'll be back.

Belt are designed to run on the V, not the top or bottom of them, when the belt wears it starts either riding on the top or bottom of the V thus slipping and polishing.

Next time DO NOT let you belt wear so far.

-Enjoy
fh : )_~