Clean the threads and both male and female with degreaser. Use blue loctite and hold the ejector rod head with a piece of leather while turning cylinder by hand. Let it sit 24 hours and you should be good. If necessary use pliers with the leather on ejector rod head.
I usually used copper jaws in the vise to tighten those (and S&W) rods and rod heads. On the Colts with the ratchet screwed to the ejector rod, they were staked from the factory and never removed unless necessary for replacement.