Can You Shorten a Sagging Garage Door Chain?

Chain-Drive Garage Door Openers

• Chain-drive garage door openers are an older type of opener. They were once a common choice because they are inexpensive and available everywhere. They are still made and sold today at home improvement stores and hardware stores. Chain-drive openers work with a shaft and sprocket-driven chain that pulls the door open. They are similar to belt-driven openers, but tend to be noisier. As time goes on, the chain may lengthen and sag a bit. Generally, a slight sag is not a problem, but if it extends too much over a period of time, you can adjust it can be easily. There are two methods to adjust the chain in this type of opener. Both methods must be done with the door closed and the unit disconnected.

Shortening the Chain

• The chain adjustment is located near the master link where the chain engages the cable. Here you will find a bolt with two or three nuts. One or two of these is for locking the unit, the other is for adjusting. Loosen the locking nut or nuts, and turn the center nut clockwise to remove the excess slack from the chain. The chain should hang no more than ½-inch down from parallel with the track.

Lengthening the Track

• The other method involves extending the track sufficiently to pull the slack from the chain. The adjuster is generally located at the top of the opener body. You turn a bolt to extend the length of the track. This method may cause the track to bend slightly, due to the rigid construction of the opener body mounting bracket. The mounting bolts may require loosening to release the tension on the opener body bracket.

Maintaining Chain-Driver Openers

• Regular oiling of the moving parts of your garage door opener will help to keep it functioning smoothly. Lightly spray the rollers, hinges and chain once each season of the year. During this task, check for any loosening of brackets or other parts and tighten as needed. Also check to see that tracks are aligned properly and adjust the mounting brackets if necessary.