1986 911 alternator question
 

I was hearing a grinding noise from my alternator. When I took the belt off it spun free sometimes and ground other times. I took it out and discovered that the black plastic cap from the end of the bearing had come out and was letting the bearing flop about. I put it back in and it spins free. what would cause the cap to come out? I am planning to get a new alternator. Am I wasting my money? This one is about 6 years old with 4k miles.

If the bearing is floating around, it's not right...
Bruce

Thanks Bruce I'll continue with my plan for a new one.