I destroyed another crank on my MTB today: It felt odd, so I checked the crank to spindle and it was solid, but it soon worsened, and I assumed it was my cheesy pedal failing - that is, until the pedal pulled out and I knew it was the crank.

- I thought precession would only tighten a pedal in a crank!

- Any ideas on what would cause the pedal to pull out of the crank?