After changing the alternator belt several times because it wouldn’t stop squealing, I ordered from the dealer a new adjusting bracket. I has a 90 degree bend at the top with a long bolt passing through a special nut in the middle that slides along a slot - you’ve seen the type. I notice that the bent part at the top was bent more than 90 degrees so even when the adjustment was all the way out, the belt would still squeal. After replacing the bracket and the belt, the noise went away. A year later now its back. What’s up with that? Is it just quality manufacturing(poor)?
It seems to be a common problem online.
The belts on my neighbors Frontier were squealing for a few seconds each time he started the engine. I tightened the belts for him 3 years ago, no problem since.