89 200 tqa - alternator belt keeps breaking

[Samir Shah <gofast1@home.com>]

Well, this afternoon the 200 lost its 5th alternator belt during my 5
month ownership tenure. Any idea why this keeps happening? Is there a
trick to this? 

This has happened with many different brands of belts - including an 
Audi branded Gates (Made in the USA), and Continental (made in Germany).
This last one lasted a whole month!

When I put them in, I need to use a lot of leverage to get it tight
enough that it does not squeal, which seems very unusual. I've put in a
new nut and bolt too.

I actually was under the car this morning, changing the cat, and checked
the belt - it was looser than when I had installed it a few weeks ago.
Am I supposed to retighten it in a week or so? Do they get loose with
break-in?

The alternator is a rebuilt unit that looks quite fresh. It spins
freely, and generates stable power. Does not make any funny noises
normally.

Luckily this happened with me in the car, and the baby had just been
fed. It'd be a real disaster if this happened to my wife when she had
the baby with her. I now carry 2 extra belts, + all needed tools to
change it, in the car, but I still don't feel confident enough about the
car to turn it back over to my wife. 

Thanks in advance. I am getting very stressed about this car. Samir.