We have a John Deere 4010 that doesn't start. We used to use it all the time. Since my dad died a few years ago we haven't been using it much, but we usually start it every 2-3 months and drive it around a little. In November, for the first time, it wouldn't start. The starter makes a whirring sound (kind of builds up) but the engine doesn't turn over. Battery fully charged. Can you offer suggestions to try?

Hi,
It uses a solenoid-shift starter, meaning it has the starter proper and a second smaller cylinder attached to it. That is the shift solenoid. It engages the electrical part and pushes the starter gear into the flywheel gear. It is not pushing or one or both of the gears are damaged.
Incidentally the 4010 is a nice CUT and you ought to "work" it more often. It happens to like to work. Also, put some diesel stabilizer in the fuel to keep the cetane level up.
Peace,
Clarke

Thank you. My brother and I only get back to the farm every couple months and we are the only ones to 'work' it now (pretty easy work giving kids rides or hauling junk around). Appreciate the insight. I will check into parts. Thanks again.