Had a service guy from local jd dealer come over today to install the block heater. It does fit as you guys described, aft and slightly below the alternator. It's a steel plug, 1/2" square recess. I would not have gotten it out myself. This service guy has done several, he says they are always tough. He tried everything, including a breaker bar with me hanging on it while he tapped the plug with a pneumatic hammer chisel thing. We tried liquid wrench. He twisted a snap on 1/2" extension. The final solution was heat. He got out a Steinel heat gun, got all the wires out of the way, set it on hi, braces it in position focusing at the plug, and we talked airplanes for ten minutes. Then he started applying force again and snap! It came out. It had evidence of green loctite in the threads. All done. The plug is pretty beat looking, so it's a trophy. It was starting to rust a bit. Tractor is a 2009. Changed coolant to latest technology.