How to Troubleshoot a Loose Chain on Your Garage Door

Do you have a garage door chain that is loose and knocking against a rail? This is one of the most common issues with garage doors that operate with a chain drive opener. Garage door chains become slack from everyday use because of the vibrations created by the motor and the weight of the door.

Tightening up the chain is therefore an important part of regular maintenance. A loose chain isn’t just noisy, it also forces your opener to do more work, making the whole system less efficient. It can also cause your door to jump the track.

A technician will adjust your garage door chain during a regular maintenance appointment, but this is also something you can do yourself if you’re handy. Here are some tips on how to do that from the garage door experts at Creative Door!


How to tighten your garage door chain

Tightening your garage door chain is a simple matter of turning the right nut. The one you’re looking for is attached to a bolt found at the spot where the trolley, or carriage, connects to the rail.

The trolley is responsible for pushing or pulling the opener arm along the chain so as to open and close the garage door. There’s usually a piece of rope hanging from it, which is used to disengage and re-engage the opener.

Step one: disconnect the power supply and disengage the opener

Before you start working, you need to take some safety precautions. First, make sure your garage is closed. Next, disconnect the power supply. If you’re not sure how, remember that most openers connect to a ceiling outlet. You can also check your owner’s manual.

Disconnecting the power supply is essential. You’re going to be up on a stepladder while tinkering with the trolley. You could be in serious danger if the garage suddenly began opening while you’re working.

Finally, detach the garage door from the opener. If you have a square rail opener, pull down on the red manual release rope. If you have a T-rail opener, pull the manual release rope down and then back toward the opener.


Step two: locate the adjustment bolt

Climb up on a stepladder and take a look at the trolley assembly. There should be a bolt on one side. It’s a threaded fastener that’s about five to seven inches long on which two nuts are screwed. One is for locking and one is for adjusting. The locking nut and the adjustment nut are separated from each other by a divider, with the locking nut being closer to the opener. Tightening the adjustment nut increases tension in the garage door chain.

Step three: loosen the locking nut, then tighten the adjustment nut

Using an adjustable or half-inch wrench, start by loosening the locking nut slightly. Then tighten the adjustment nut, which will, in turn, increase tension in the chain. The chain should be tightened until it sits, at its midpoint, about a quarter-inch above the rail for a square rail and a half-inch above the rail for a T-rail. It’s important that you don’t over-tighten it, as this will cause the chain rollers to wear out prematurely. In fact, as a rule it’s better for the chain to be slightly loose rather than tight.

Once you’ve adjusted the chain to the proper tension, tighten the locking nut. You should use two wrenches for this, one to hold the adjustment nut in place and the other to turn the locking nut.


Step four: reconnect the power and then re-engage the opener

Plug your opener back in, then re-attach it either by pulling the manual release rope back toward the opener until the trolley snaps back into place or simply by opening your garage door with the wall button, which will cause the trolley to snap back into place automatically. When you re-engage the opener, you may notice that the chain begins to droop a bit. This is normal: the chain will regain its tension when the door is in the open position.

Step five: perform a test

Open and close your garage a few times to make sure the issue is resolved. If the chain is still knocking against the rail, tighten up the adjustment screw a little more.

You shouldn’t have to worry about your chain’s tension for at least a year. However, if your chain is frequently going slack, this is a sign that either it or your opener needs to be replaced. Chains and openers are both vulnerable to gradual wear and tear. You can check out our selection of garage door openers available at your local Creative Door location.

Garage Door Repair Services in Western Canada

If your garage door chain needs to be replaced, tightened, or if you require any other garage door maintenance or repair work, count on the technicians at Creative Door Services. For more information or to schedule a service call, reach out to us  today, or contact one of our eight branches across Western Canada.

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