I've had this same issue as well and thought too that the issue was with the steering column and mating gear assembly. Upon closer examination, the issue ( at least in my case) was that the tie rod ends had worn away the hole in the metal fins that turn the wheels when you turn the steering wheel. The original fit is nice and tight but over the years and with no grease, that hole gets enormous and the steering gets really sloppy. Eventually, it gets so sloppy that the steering column no longer mates with the gear assembly. It's a really crappy design by JD and for all of us that bought John Deere tractors (and paid quite a premium over the competition's tractors) because they were supposed to be indestructible and reliable for years, there ought to be some recognition by JD that this is caused by a design flaw and nothing else. That design will never stand up to the thousands of turns one will take over the years. They really phoned it in on this one. Shame on you JD.
NeverbuyaJDagain, August 2013