Ive seen the TSB, and I know what parts need to be replaced, but I was wondering if anyone (including Nissan/Infiniti) has ever said exactly what breaks?

I have my seat out right now and took the forward/backward motor out of the drive assembly. It looks like the brushes are not replaceable, so it makes me wonder if we are replacing 200.00 worth of parts just for new brushes?

Im going to clean off the armature shaft where the brushes run, as its pretty dirty (presumably from the brushes wearing away). Not sure if this will fix the problem though. There does look like there is a decent amount of brush left, but Im just not confident cleaning the armature will fix it (at least for an extended period of time)