Replacing the brushes/rubber bumpers on the alternator.
Remove the tool tray, FI computer and battery to get access to brush holder at the back of the alternator
Remove the 2 screws and pull the brush holder
Since the alternator is accessible, it is recommended to pull it from the engine and check the rubber bumpers (#9 ).
Remove the 3 screws (#5) and pull the
alternator away from the engine.
This is an example of broken bumpers:
Part list for the alternator: