i probably didn't write clearly. i only broke those cast aluminium pieces that actually hold the bars. they didn't break while running. they would slip down the eat stays. so when tightening they shattered. the 2nd one i tried to tighten less & it would slip. when i tightened. it broke. changed to a u-joint repair kit. i can tighten all i want. i'm 3rd generation radial air plane mechanic. well ok, i'm not a licensed mechanic but i didn't need once since i worked in the shop that is licensed.