See you have had a couple dozen hits on this post but no replies. Wonder if it could be others including myself aren't exactly sure what you mean. These models have a hydrostatic steering system. There is a valve assy attached to the steering column.
Here is something I found in an old service manual that might be of help.
Yanmar FX 24D
Yanmar RS 1300 tiller
Cub Cadet 3204
48" HD mower
Bolens 1257 w/36" tiller
"democracy" will cease to exist when you take away from those who are willing to work and give to those who would not." - Thomas Jefferson
May the most you wish for be the lest you get, but work for it. - Ray Briem
The problem with Socialism is, sooner or later you will run out of OTHER peoples money. - Margret Thatcher
Thank you for responding to my post. I am sorry my request was not as clear as it should have been. The information you sent is excellent! I now know that I need to disconnect the drive shaft to lower the unit out of the tractor. Any other advice you have will be appreciated. Thank you. Thom Mcknight
One thing to look at first is the bottom of the steering column and determine if you have a 4 or 5 port column. The plumbing is different on the two. With the 5 port system the hydraulic system use does not stop the ability to steer while in use. It appears the earlier models Jane the 4 port and later models have the 5 port. I converted my JD317 to JD318 power steering. The 5 port is much better.
Thank you for the information. With the help of a friend a new steering column has been installed. It wasn't the easiest repair, but it is finished with a column the does not leak and works perfectly. Thanks to all who advised.