Good morning everyone, I am new here, just bought a ford **! serial number worn off so I don't know the exact year. Diesel select-o-speed, and PTO. I was using it pulling harrows for about two hours and all of a sudden a loud knocking noise so I parked it. It has been a few weeks and I finally was able to get around and drop the oil pan. The piston most forward in the engine has one side of the piston appears to be smashed in. If found some small metal shavings in the oil pan but nothing major which looks like it has come form the piston damage. Does anyone have any ideas of what might have caused this or could it just be wear and tear and perhaps time for this part to fail?