i hate to say it but one of the pix, looks like that ring is reverse-threaded
hard to tell though
and if you have moved it all in any direction, that is the correct direction…
if that makes sense
FORGET THAT
now i cannot tell
and if i am wrong, trying to go the wrong way, just makes things worse
wle
In the first post picture, there appears to be a split ring between the collar ring and the emitter reflector that lines up with the half moon at the 8:00 position. Follow clockwise from there the ring is exposed and then is pinched under at about the 2:00 position, where it is hidden under the lip until it is seen coming out again.
In another picture a split in a complete ring can be seen, but then it is obscured later.
Try turning it clockwise (reverse direction) to see if it will move, it might have left hand threads and you have been trying to tighten the collar and the split piece was squished out.
What appears to be a gap in a split ring in the first picture is simply where he has gouged the aluminum. You can see it easily in the first picture in the second set. I’m sure he’s been putting nails and one end of his pliers in that half moon hole and he has gouged up the threads badly.
It would be nice if you could use an impact wrench to break it loose. Worked on many of my car projects where a breaker bar would not budge the bolts. But I guess if you’re tenacious enough, you could make a special tool and attach it to an impact wrench (if you have one). This is the one I bought from Harbor Freight:
