Welcome to the forum. It is a common problem for most of the older tractors. The steering gear is adjustable for taking out the free play in the wheel. You shouldn't need to remove it unless it is totally shot. There is a grease fitting as well. I recently got a 314 with the same problem. If you download the CTSM for the 140 from the manuals section of this forum it has the same steering gear. The procedure for adjusting out the slack is in the CTSM. The other problem areas are the front axle centre bushing which is available from JD
for a few $. Also the bushings in the steering linkage can be worn. The front wheel bearings are another common wear area as well as the tie rod ends. I replaced all this stuff on mine and it was adjusting the steering gear that finally tightened up the steering to like new.
If you turn the wheel you should be able to see the linkage and steering gear moving. Then you can see where most of the slack is.