What can make a alternator go

I have an 02 Montero Sport ES 3.0L 2WD, I dont know if it would be the same problem but I recently had this done. I have 118K miles on it: the cam shaft and o-rings were leaking and causing the oil to drip into the alternator and short them out. I have purchased 4 alternators over the course of the 5 years that I have owned this vehicle and went through 3 mechanics to finally figure out the problems. It cost around 1700$ to fix.

WOW! $1700... these alternators are easy to replace...buy an aftermarket 85 Amp...(not the stock 70Amp)... replace once...about $200...look around or buy from Autozone (lifetime warranty)...I taught my daughter how to replace...loosen belts, disconnect, two bolts...yippee skippy... I've owned 5 Monteros... common problem