Help! Mercedes trapped in garage by broken garage door cable!
 

Call an overhead door company. The cable needs to be reattached and the spring re-tensioned. Unless you're brave and know what you're doing, this is not a DIY job. The spring stores enough energy to kill you.

As long as the other cable is still attached, there is no need to do anything with the spring. The affected cable drum can be disconnected from the shaft and the cable reinstalled. Then remove cable slack by rotating the drum independent of the shaft, then tighten the drum screw(s) back down.

Then you need to investigate the cause of the cable problem. Loose hinge fasteners area high-probability culprit.

There is nothing apparently wrong with the cable as presented. It just needs to be reinstalled. All you need to do is loosen the drum, attach the cable, remove the slack and tighten the drum back down.

I just helped my father in-law install a new spring on his garage door. The old one snapped and scared the heck out of my mother-in-law this week.

Nothing wrong with call in for reinforcements when you feel the need for backup.

-CTH

For anyone not comfortable with doing it, I agree. I've done it many times, it's not that tough, you just need to focus really well and have the right wrench at the ready. You can get a 36 steel rod, 1/2 inch dia at home depot, cut it in half and you have your tensioning tools. You turn the hub 90 degrees and then put the other rod in the next hole. The tightening nuts are square, a good Crescent wrench will do. Specialty wrenches are available.

The harder part is turning it the correct number of times. If there are two springs, I'd unwind the other one and count the quarter turns. You want both springs to have the same tension of course. One way to get the correct tension is to tighten each spring to say 10 or 15 turns each and see if the door will stay stationary at about 4 feet open. Or do that with one spring if it's a single. Tighten gradually until it will. IIRC about 25 quarter turns is about what they usually take.

If you do it yourself, make sure the plane that the tightening rods turns in is never aimed at your person.

When replacing ONE cable, there is NO need to do anything with the torsion spring. If we are going to "focus," why not focus on the actual job that needs to be done rather than promote all this fear-mongering about the torsion spring?

I'd have to see it in person to get an idea of what's going on but based on the fact of his saying that it won't open, I was thinking there must be some issue with the spring. If the full spring force is applied on one cable only, I would think one could muscle it up w/o too much trouble. It's been a few years since I replaced a spring and I recall having to thread everything up with no tension. But with one cable only, who knows, you might be right. I'd have to be there to know for sure.

These tend to come off when opening door too quickly, the drum struggles to keep up throwing the cable off.

Reinstalled mine after looking at the other side which was still attached, your design maybe different though.

Not recommending you do this yourself if uncomfortable with overall operation, it takes some working out as to what does what.

Personally, I hate springs and go to great lengths covering up with safety goggles and so on, this weekend put a new aux belt drive on my 124 - releasing the spring on that stood well to the side lol.

Going back to the door mechanism, mine had no lube on, might go back and grease the wires unless not advised.

If there is only one spring. You are not going to be involved with it. By replacing just one cable on one side.

Basically just loosen the pulley on the side with no wire. Attach the new cable on the bottom of the door fitting. Install the cable end fitting in the pulley and roll the slack out. . Then tighten the pulley bolt. Trying to get the wire as tight as possible with no slack. Ideally the tension should seem about the same as the other side.

If this is not achieved just raise the door a little and put a brick under the same side. Loosen the pulley again and take up a little slop in the wire. As long as you are not playing around with the spring in any way and there is only one. It should go safe and easy.

On the other hand if you have any self doubts a door guy can do it pretty fast. Maybe check with a few for prices as this is also a deal where many doing it are scammers.

Check the cable that broke for rust. If any do a visual inspection of the other one in place. After you or the door guy get finished. Rubbing a little grease into the wires will probably extend their service life.

Yes I have installed much heavier roll up doors. With very strong springs in comparison to domestic garage doors. You are not installing a door with the risks involved. By Just replacing a cable. The bolt that locks the wire pulley to the main shaft should be pretty tight. It could also have slipped a little causing this.

I agree that it can be done this way, but it is NOT that simple. If one cable has all the tension on it, just taking all the slack out of the other cable and tightening the set screws will not work properly. You will NOT be able to get the same tension on both sides, and the door will not go up and down evenly. Also, the loose cable will tend to come off the drum a lot easier. For those of us that have experience with overhead doors, it is no big deal to fix something like this. What cmac2012 says (post #7) is absolutely correct, but still may be above HuskyMan's pay grade. I suggest as others, and agree that HM should call a professional. He will find that the technician will remove the tension from the spring/s and start over.

EDIT: It seems while I was typing, the above post made by HM makes mine void. However, for others reading this thread, the cautions & warnings remain......Rich

That sounds plausible. If the door is down, the pulley on the other side, being still bolted tightly, is going to keep the spring safely tensed. There is a small learning curve on how the cable is attached and rolls off but it's not hard to figure. The only thing that concerns me is that the existing cable is going to be tight. Getting the other cable as tight with regular human muscles before cinching it down with the bolt might be tricky. If the spring is first slackened, then you can get both cables about the same tightness before retensioning the spring. But who knows, a slight difference in cable tension might not be a problem.

I have done a few springs, and cables. There should be a dab of paint on the spring, maybe white, red, yellow which indicates how many revolutions you put on the spring when tensioning. The supply store that you purchase the cable should tell you that number. No trial and error. Also a little white lithium on the spring and silicone spray on the cable and track while you are there.