Ron, it may be time for a new belt, but your local auto parts store
should have spray cans of belt dressing.  I had same problem recently on
my '84 as belt installed a while back had stetched a bit and was
slipping.  A couple of shots of belt dressing solved the problem.

John

On Thu, May 11, 2017 at 9:02 PM, The Bus Depot wrote:

> The alternator belt on my '87 Westy screeches horribly at idle, and
> sometimes when you first pull out from a stop. (It stops if you gun
> the
> engine, or while driving at almost any speed.) Replaced the belt and
> the new
> one started doing the same thing after only a few hundred miles. The
> belt
> tension is correct. The mount looks okay and nothing seems visually
> wrong
> with the geometry. The alternator does not seem to be binding. One of
> the
> pulleys had a bit of surface rust but sanding it off made no
> difference. No
> hot spots when viewed with an infrared heat detector. Running out of
> ideas.
> Any thoughts?
>
> Ron Salmon