After 150k miles I figured it was time to rebuild the trusty alternator. It is a BOSCH 90A model. It is really pretty simple,I just followed the instructions out of the Helms manual with the following exceptions: you need some type of puller to remove the bearing, The book shows a shop press, but a simple gear puller will work. Do not unsolder the stator wires to rectifier unless the alternator is malfunctioning.
I did the following repairs. I replaced both the front and rear bearings, I machined the commutator smooth on a lathe ( This could be performed by chucking the rotor in drill and machining it with a file ). The brushes/voltage regulator was also replaced. Being the Anal retentive mechanic that I am I also had to Bead blast the case and repaint everything, but hey that is me.
1: FRONT BEARING FEDERAL MOGUL 303 CC $11
2: REAR BEARING FEDERAL MOGUL 201 CC $8
3: REGULATOR/BRUSH GP- SORENSEN 26-5046 $18