Every so often a more mechanical than electrical device finds its way into my work area. A local machine shop had a pair of Makita GA-5020 angle grinders that had been used and abused and needed some work. One didn’t work and the other had some vibration issue. I found a nice exploded parts diagram and replacement parts available at eReplacementParts.com although shipping to Canada is a bit cost prohibitive. The one which didn’t power up needed new brushes, and the other seemed to run a lot smoother after the rebuilding and regreasing of the gearbox and bearings. I went over the switches as well for good measure, regreasing them and deoxidizing the plating.
Here are some before pics posted on after the other. The exteriors look like hell even after cleaning, but they cleaned up half decent on the inside.
Exterior:
Lower gearbox housing:
Upper gearbox housing:
Brushes:
Commutator:
Switch assembly:
Ball bearings:
