I just had this happen today. Got a clog, had to disassemble the extruder to get to it. I went ahead and installed the hardened steel extruder and the hardened steel nozzle to go with it, but I can not get any proper feeding now, and 99% of the time it’s failing to even load the filament. When I took it apart again to look at it, I saw that there were spots on the top of the hot end itself where it looked like the filament wasn’t able to feed into the nozzle properly. I noticed that the extruder gear now is loose (i.e. it goes back to front). When I pushed it back as far as I could, it let the filament load, but then I had horrid under extrusion and couldn’t get anything to even get past the initial layer. I made sure all the parts were accounted for when I did the replacement so I can’t for the life of me figure out what’s going on.
Hello, yesterday i wanted to replace my extruder gears with a hardened steel version.
So basicly i did the same as you did, with the exception of replacing my hotend.
I noticed 2 things:
1, the bearing in the small part of the gears was extremely worn, the bearing grinded like hell! I never saw a problem, so gladly i did the change before it got problematic.
2: i forgot to place the bearing on the big wheel (the one that should be in the smaller case you remove), and that gave me the same result of the gear going from front to back)
Ps, my machine has printed +/- 10 rolls of pla.