Looks like there is no locking nut on the threaded rod. It will come loose again .

Got it all hooked up and working, only issue i'm having when the door is going down, and is down..the tubing on the unit, or track i'll call it, bows up in the centre from pressure. With the door down, I can pull the emergency release cord , the tension releases and the plastic housing the turnbuckle sets in will move in the direction of the motor about an inch or two past the turnbuckle. I tried moving the bracket on the door, I tried tightening /loosening the chain . tried redoing my open / close points etc . No luck keeping that from bowing . Stumped!

Bought one of these POS today. You called it correct at the end when you pointed to the plastic housing the chain turnbuckle goes into and said there's the weak link. Why they wouldn't have spent $10 and made that out of metal? So when i'm tightening my chain on the turnbuckle, just as you do, it builds up pressure , or puts a twist in the cable and as soon as I stop tightening it it spins itself backwards and loosens. Instructions say once you get it to the desired tightness, pull the little little horse show clip out of the turnbuckle. Hard to do that when it keeps falling out on the floor on it's own when I'm tightening the chain ! Had to walk away for the night or there would be a garage door opener and a garage door down at the road for pick up on garbage day

The bottom of the chain at it's lowest point should be 1/4 to 3/8" above the bottom of the rail. Your chain is still too loose.

Nice man

dont show fingure man