I just bought a G0704 from Grizzly, and I've read a lot of notes that talk about breaking plastic gears in the headstock. I figured the best way to prevent this was to order a spare with the mill. So, I talked to technical support and they had me order part P0704209 GEAR 37T, which appears to be the gear that is driven by the gear on the motor shaft. It was, and still is, backordered.
I then noticed in a YouTube video, someone was replacing a different plastic gear, the double one that slides to change speeds. I believe the part number is P0704212, GEAR 42/62T.
So my question to any and all that have broken a gear in a G0704. Which one did you break? Part 209 or part 212?