As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) HYDRAULIC BODY HAS A STEP UNDER THE TAPPET FACE THAT WAS NOT MACHINED PROPERLY. THIS CAUSES THE CAMSHAFT TO BIND AGAINST THE TAPPET FACE AT INSTALLATION DUE TO THE REDUCED CLEARANCE. THESE TAPPETS SL72877 WERE FOUND IN CAM KITS SL19340 DATED 04/23/2018. (TC# 20180907014)