Phil, If the commutator had required attention I would have dealt with it. It showed no significant wear so I cleaned it and re-assembled it all. As I've said, this was several years ago and the car has had almost daily use since including long trips abroad, so whilst it may be "half a job" in your opinion, it does appear to have worked fine so far.... Surely this just goes to show how reliable a system the dynamo isphilthehill wrote: ↑Thu Apr 18, 2019 7:56 amWhen replacing the dynamo brushes the commutator segments must be parallel not uneven where the brushes have worn them (usually rectified in a lathe) and the commutator segments must be undercut. See BMC wksp man Fig. N5 for details.
Just replacing the bushes is only doing half the job.
By contrast, the brand new alternator fitted to my daughter's Minor didn't last nearly as many years or miles as my dynamo brushes before another new one was required.