Replicator 2 making strange grinding noise - extruder gear worn out?

[Zhall]

Dragon,

I tried loading with the front fan and heat sync off so I could observe what was going on. There was no grinding during load/unload.

I tried printing without filament and the grinding persists, although it is not very frequent, only showing up on long paths that the extruder makes.

When I hold the side fan (not the main cooling fan) the grinding seems to get a lot quieter, my hypothesis is that that fan is rattling inside of it's case when not in use?

As for the bearing I haven't looked into that yet.

Edit: This only happens on large parts, I just did a whole build without it grinding once.

I noticed that if the filament touches the side of the extruder feed hole then the vibrating starts.

I think it is simply the fact that the guide tube doesn't stay in place during a big build, and the filament is vibrating against the walls of the extruder feed.