I disliked the stock tailwheel steering linkage as soon as I looked at it. It's a steel tube, with a flat tab welded on each end that you're supposed to drill to the arm on the tailwheel caster and the rudder drive horn. The problems with this are:
1) Once you drill the holes it's not adjustable for alignment.
2) You can't tighten the bolts very tight or it squeezes the tab against whatever you're bolting it too, so it doesn't pivot. You have to leave the bolts slightly loose, which will cause it to rattle around and enlarge the holes over time.
3) The rudder drive horn and caster arm aren't quite parallel, so you have to bend the steering linkage for the tabs to mate up.
I gave it a try anyway, and I didn't really like the results. I got the alignment as straight as I could and drilled the holes, but I was mainly concerned about items 2 and 3. I messed around with trying to bend the linkage slightly to get the tabs to mate up nicely, but it still didn't work that well. I could either leave the bolts quite loose, which resulted in really sloppy steering, or I could snug them up, which created an excess of friction in the rudder.
I didn't like it, so I took it off and considered making my own linkage with some aluminum rod and rod end bearings, but I found that I could just buy exactly what I needed for not much more that I would've spent making it:
http://www.ansoneng.com/sample-page/products-summary/6-pneumatic-tailwheel-to-suit-sonex/
I ordered the tailwheel linkage and it arrived ready to install:
I had to enlarge the mounting holes from 3/16" to 1/4", and then it bolted right up. I got the alignment as close as I could by eyeballing it, and now I'll be able to make adjustments later if necessary. Much better! I definitely recommend doing something like this for anyone else reading this. Either make your own or just order one from Peter Anson. The price was well worth the headache saved, and even coming all the way from Australia the shipping was pretty cheap and fast.
While I was looking at the tailwheel I also took care of service bulletin #SNX-SB-008, which replaces the machine screws that attach the steering arm to the top of the tailwheel caster. I just removed the screws, drilled out the holes, and installed the longer screws and prevailing-torque nuts called for in the bulletin. Details here: https://www.sonexaircraft.com/service-bulletins/
