Apr 20, 2009· John Grinder Mixer, What Year For First? discussion in the Tractor Talk forum at Yesterday's Tractors. ... I have a JD400 grinder mixer that I use once a week to grind ear corn. I always thought it to be a early 60's vintage. The manual shows it with a 4010 hooked to it. ... This was 's first grinder mixer with their name on it. They ...