(Scroll down for video and photos.) When Dan, the owner of a nice A36 Bonanza called me and reported a “clunking noise” at the right main landing gear while moving the airplane by hand, I was stumped. So I did what I like to do when I have an airplane puzzler… I sent an email to my aviation friends, and I asked for ideas about what might be causing this clunking noise. I received great feedback and guesses about what might be causing the mystery noise. Wheel bearings? Brake caliper / linings? Landing gear bushings? Etc… But when Dan arrived at SHD to drop his airplane off for the annual inspection, it was no longer making the clunking noise. We agreed I’d check it out during the inspection. When the time came to put the airplane on jacks and remove the right brake caliper and wheel, I did not notice anything obvious. And then I noticed something. There was a tiny spot on the brake disc that I could catch a fingernail on. Check it out: (And by the way, if you are seeing these show notes in a podcast player like Pocket Casts, the following 11 second video may not appear; if this happens, scroll to the bottom and click the link for my website and you should be able to watch the video there.) I also made a more detailed video of this story and it’s on YouTube here: https://youtube.com/shorts/XuTnm-qQne0 Then I also noticed there was a groove on the brake linings that seemed to match the spot on the disc. Take a look: It appears there was some metal transfer between the brake disc and linings that created a raised “bump” and I wonder if this is what caused the clunking noise as the wheel was rotating during ground tugging. It’s the best explanation I can come up with. Both the left and right brake discs were worn below minimums, so I installed new ones along with all new linings. I installed APS “Blacksteel” discs and APS linings. In my opinion, the APS discs are of exceptional quality, and the APS brake linings are far superior to the Rapco linings I removed. If you’re interested in more info about APS brake parts, here’s the website: https://www.apsbrakes.com Listen to the audio for more details. Now, one more thing I forgot to mention when I was recording the podcast episode… when I removed the right brake linings, there were some strange, seemingly magnetized little pieces that were attached to the brake lining and backplate. Here’s what it looked like: Perhaps this tells a part of the story as well, but I’m not sure what it means. If you have a thought on this, send me an email to dean{at}airplaneownermaintenance{dot}com The post “259 – Bonanza Clunking Wheel Noise Solved!” appeared first at AirplaneOwnerMaintenance.com