I was looking for some information on how to rebuild the generator and came accross the fowlling. They say the bearings can not be replaced.....we'll see?

Charging System Description
Generator
The AD-230 and AD-237 generators are non-repairable. They are electrically similar to earlier models. The generators feature the following major components:

The delta stator
The rectifier bridge
The rotor with slip rings and brushes
A conventional pulley
Dual internal fans
The regulator
The pulley and the fan cool the slip ring and the frame.

The AD stands for Air-cooled Dual internal fan; the 2 is an electrical design designator; the 30 denotes the outside diameter of the stator laminations in millimeters, over 100 millimeters. The generator is rated at 105 amperes.

The generator features permanently lubricated bearings. Service should only include tightening of mount components. Otherwise, replace the generator as a complete unit.

Regulator
The voltage regulator controls the rotor field current in order to limit the system voltage. When the field current is on, the regulator switches the current on and off at a rate of 400 cycles per second in order to perform the following functions:

Radio noise control
Obtain the correct average current needed for proper system voltage control
At high speeds, the on-time may be 10 percent with the off-time at 90 percent. At low speeds, the on-time may be 90 percent and the off-time 10 percent

I believe GM sends alternators out to be remanufactured. So you know that the front & rear bearings are replaceable. I had two new alternators replaced under warranty on my '97 SE(the first two years I owned it). I know they didn't throw those alts. away, they're in some one else'* car right now making power.

I would assume it depends on the status of the alt. But if they are in bad enough shape to replace, as opposed to just fixing them up, I dunno that they would rebuild them.