[BrianG]

If you get a metal spur, you MUST get a hardened pinion. Not only is the metal hardened, but the shape/angle of the teeth match that of the steel spur. I can't tell for sure, but it looks like your current pinion is the regular steel type Mike used to carry a while back.

And as a bonus, the hardened type works with the plastic spur too.

Looks like you need a new pinion anyway no matter what you use for the spur.

Although, I would fix what the underlying issue is or you'll just keep eating spurs/pinions.