From looking into this it seems that the 245 was fitted with the older mechanical type of steering and hydrostatic. If you have the older type then it is likely that the play will be in the rocker shaft tooth mesh items 52 and 17 in the diagram. There is no adjustment only replacement. You may also have wear in the top bearing of the steering column. Normally this can be adjusted after removing the steering wheel. In older tractors it is not uncommon to have to cut the steering wheel off.
Let us know which type you have.
DavidP, South Wales