Lessons learned--Not by me but by customers. Working for a dealer gives you a chance to see the differences in manufacturers and customers.
1. MM diesels Cracked heads One farmer learned the hard way not to shut the tractor off quickly after a loaded pull. He was out plowing, the wife brought lunch, without even lifting the plow or pushing in the clutch, he shut it off to enjoy the quiet and his lunch. A week later he had an issue with water pushing out the radiator. Replaced both heads as they were cracked from heat soak. MM used one head for two cylinders. Lesson learned
2. Local farmer brings combine in for service. Notice when he shut it down did so wide open. Asked him to move it. Noticed it6 started and immediately roared to wide open. Asked if throttle worked he replied "Yes". I asked him if he treated himself like the combine. He asked why. I then asked him if he went to bed while working full bore, and if he woke up and immediately started working hard. He got the hint. But he later did destroy an engine while leaving it "warmup".
3. Turbocharged Oliver had a decal on dash. Idle engine 5 minutes before shut down.