Can the Alternator Bearing Be Replaced?
 

I have a 78 911 SC. The alternator works fine, but the bearing is starting to make a knocking noise. (I think its the bearing because I hear a knocking noise when the engine is running. When I take off the fan belt and run the engine for a few seconds, the knocking is gone). Is it possible to have the bearing replaced? That sure would beat $200 for another alternator. Thanks.

Brian:

I'm not sure about the Paris-Rhone or the Marchal, but I replaced the front bearing on a Bosch with good results. The only tricky parts were to get the pully off without damaging it, and to press the bearing out of the cast housing without cracking it, the rest was easy. It's a good time to replace the brushes and check the diodes too.

Tim