I was talking to one of my mechanics, Stephen, the other day about my Piper airplane control yoke shaft binding when I moved the yoke in and out for pitch changes. The yoke grabs and lets go, and grabs and lets go — it’s quite frustrating. As I was describing the issue he smiled and said, “yoke chatter,” and I just laughed. Can you actually believe that there’s a name for this? Too funny, I thought, but how do you actually solve the problem?
Stephen said that there’s a variety of ways and one of the easiest is to purchase a can of spray silicone from your local hardware store. Other things like rubbing alcohol work well, too, but I like silicone because it both cleans well and lubricates. Spray some on a paper towel or rag and wipe it on the shaft. Do all sides, top and bottom, for the full length.
If you haven’t done this for a while it will be quite dirty and you’ll need to clean the shaft again until you know it’s clean. You will need to do this about every six months or so and don’t forget to do both yoke shafts!
One other thing. When you’re doing this move the yoke up and down, and left and right while the yoke is pulled out. If there’s significant wiggle it means that the bearing in the panel that the shaft goes through is worn out. Since most of our planes are decades old this happens a lot and I’ve had to replace those bearings three times in various airplanes. Also, I’ve only had to replace the left bearing because that’s the yoke that gets used most often. Since the left bearing wears more than the right bearing you can compare the wiggle for reference. You can also check yours against a friend’s plane. If in doubt, put it on your squawk list for your next annual inspection.