The summer before he died, he'd brought home a thick, stained service manual for a John Deere 4020. Its spine was repaired with brown tape, and several pages carried pencil marks beside drawings of the engine. He had worked on a few of those tractors years earlier and liked the way the manual showed a machine as a collection of systems rather than a single stubborn lump of metal. The 4020 became our classroom for six weeks.
We traced how air entered a diesel engine, how fuel was delivered and timed, and how the six cylinders converted combustion into the slow, powerful rotation that moved a tractor through a field. We talked about lubrication, cooling, compression, and what could happen when a machine sat unused under an open exhaust for too many wet seasons. Grandpa drew little arrows beside the printed diagrams and made me explain them back to him. Some nights I was so tired I wanted to shut the book and go to bed. He would close it himself and say there was no point teaching a sleepy boy to make mistakes with expensive parts.
"These engines don't just forget how to run," he told me one night, tapping the diagram of a wet cylinder sleeve. "Sometimes people leave them where the weather can get in, and time does what time does. That doesn't mean you can buy every ruined one and bring it back. It means you ought to find out exactly what's wrong before you decide it's dead."
I liked the first half of that lesson more than the second. At twelve, I wanted the heroic version, the one where a clever kid saw what experts missed and brought a machine to life through determination. Grandpa wanted me to learn that determination without measurement could become a very expensive way of being wrong. He made me write dimensions and observations in a notebook. He never let me say "probably fine" when I hadn't checked.
After his funeral, I kept reading the manual because opening it made the evenings feel less empty. I read the same pages about wet sleeves and injection pumps until the diagrams were more familiar than my spelling homework. I watched repair videos at the library because our internet connection dropped every time the weather turned bad. I asked mechanics questions when they weren't busy and wrote down the answers whether I understood them or not. I didn't tell anyone I was looking for a tractor. I was looking for something to do with all the things Grandpa had taught me before I lost my chance to ask him anything else.
On a Thursday in October, while sitting on the library floor between two shelves of old farm magazines, I opened the county auction listings on a public computer. Most of the machinery was too expensive to consider. Some of it looked worse than the Case we already owned. Then a photograph loaded slowly onto the screen: a green tractor sitting beneath a stained tin roof, with a square white tag hanging from the steering wheel.
Lot seven. 1967 John Deere 4020. Non-running. Engine reportedly seized. Stored approximately twenty years. Sold as parts only. No guarantee of condition.