Hey mate. check the above thread. Take the brush holder out and check the length of your brushes (Not sure if yours will be the same design though). If they seem pretty low then either do as Stew is saying or find a place that does exhange holders with the new brushes(got mine for $25). I showed the alternator to the auto elec (for piece of mind) when I picked up the brushes and he said the bearings seemed fine and the slip rings weren't too bad if I sanded them a little.
The alternator has been going fine for the last few months and expect it to last the life of the car...