So I finally got around to installing my cooler. Everything was going well until I installed the two bolts that hold the cooler itself to the support arm. I had tightened the top bolt to roughly 5 Nm when spin spin spin.
The lock nut had not even flattened!
The instructions do say not to overtighten,
but I can only assume mine was especially weak. I am usually not surprised when I strip things. This time I was! The only thing holding it together is a very small (1mm?) collar of aluminum. I had it welded back, threw some paint on it, and finished the install predictably.
The kit is great, and, as previously mentioned, the instructions are impressive. We're finally getting some rain here, so while I fired her up to check for leaks, I haven't taken her out. Thanks again, Mark.