The steering linkage on my John Deere RX75 Riding Mower needs to be tightened.

The steering wheel moves - but does not catch on the steering gears.
The tires do move (if I do it by hand) - occasionally the gears will catch a little and the tires do move.

http://www.flickr.com/photos/40794180@N03/3756285728/

http://www.flickr.com/photos/40794180@N03/3756286216/

Hi,
Hate to be the bearer of bad tidings, but you will need to reolac the steering shaft (part #AM101716) and steering gear (part #AM103950) to fix this, No adjustment exists. You should think about the bushings on both as they may well have worn allowing too much play. They will be a pittance pricewise, and are shaft bushing (part #M81463) and gear bushing (part #M73163.)
I do not guarantee you will like the price; maybe you can get a discount since they do not have to look up the part numbers.
Note: During reassmbly, should you do it DIY, you MUST have someone hold up on the assembly while you fasten the steering wheel back on or it will all fall down. Make sure not to have much up and down play in the shaft either.
Peace,
Clarke