The APS (Adaptive Preload System) adjuster was always coming loose on the e*thirteen TRS+ cranks that came stock on a 2017 YT Capra CF Pro. I emailed e*thirteen and they sent a new APS adjuster. Installed and had the same problem. The APS adjuster is hand tightened. The solution was to install 2 of the metal lock washers in the same orientation and apply blue Loctite to the threads of the APS adjuster. Crude but it works. Torque the crank bolt to 35 ft-lbs. To keep the crank bolt from also coming loose, I removed all grease from the crank bolt and crank threads and applied blue Loctite to the crank bolt threads. It’s a poor design. The APS adjuster needs a lock ring like the Raceface ones have which I show in the video.