Garage Door Slams Shut? Here’s What’s Wrong and How to Fix It
It’s the sound of a slammed garage door – the kind of loud, bone-rattling slam that vibrates in your garage and rattles the walls. Your heart jumps: Did I break the door? Crack the concrete floor? Dent the car?
A slamming garage door can be more than an obnoxious and socially-embarrassing occurrence when guests or neighbors are visiting. A slamming door is a loud and clear indication that a major failure has occurred in your garage door’s counterbalance system. Instead of slowly lowering under very controlled tension, your garage door is now free-falling under the full unleashed force of gravity – hundreds of pounds of mass smacking into the floor.
Why Is My Garage Door Dropping? Understanding the Problem
Your garage door’s spring system is designed to take the weight of the door off of the opener, so it only has to guide the door up and down rather than lifting it. If something breaks in that spring system, there’s nothing to resist the door’s fall and it falls freely under the weight of gravity. Once you understand the counterbalance system, it’s easier to diagnose what is broken: springs, cables, seized rollers, or opener adjustment.
Culprit #1: Broken or Worn Springs (The #1 Cause)
Torsion Springs: Located horizontally above the door opening. A break in the spring will be obvious with a loud bang and a visible 1-2 inch gap in the coil. When a torsion spring breaks, you will experience the most violent slam possible because the entire counterbalance system disengages simultaneously.
Extension Springs: Located parallel to the horizontal tracks on both sides of the door. A broken extension spring causes the door to hang unevenly and drop suddenly on one side as the remaining spring is overloaded trying to balance the door weight.
Culprit #2: Broken or Frayed Lifting Cables
Lifting cables: Stretch from the bottom corners of the door through a pulley to the spring mechanism. Cable failure is common when springs break. The cable will unwind from the pulley, become frayed and/or snapped. When a cable breaks or frays, the door will suddenly drop on one side causing an uneven and jerking slam even if the springs are not broken. Damaged cables are a common cause of slamming that may or may not occur with broken springs.
Culprit #3: Worn Out or Seized Rollers
Rollers that do not spin freely in the tracks may cause the door to bind up in the tracks then suddenly drop when the friction is overcome. They are an uncommon direct cause of slamming but can cause a jerky, stop-and-drop motion that is similar.
Culprit #4: Opener Travel or Force Limit Misadjustment
If the “down” force limit is too weak, the opener will not slow the door’s descent in the last foot or so before the door reaches the ground. Improper opener settings will not usually be a problem until after a spring problem has developed.
How to Fix It: Your Repair Options
If your garage door slams shut or down, you should correct the problem immediately to avoid injury or property damage. Here are some common repairs depending on the cause of your problem.
- Test the counterbalance: Disconnect your garage door opener and raise the door halfway by hand.If the door falls down quickly, your springs have broken and must be repaired or replaced immediately by a garage door professional. If the door holds its position by itself, the problem is probably with the rollers or the opener settings.
- Replace bad rollers: If your counterbalance test showed healthy springs, but your door has stiff or seized rollers, replacing them is an easy DIY job. Raise the door all the way up, remove the bolts holding the brackets, slide out the old rollers and replace with new nylon rollers with sealed bearings. Reattach the brackets with the new rollers in place.
- Adjust opener limits: If your door slams in the last foot or so before it reaches the closed position, you can adjust the limits on most garage door openers by using the adjustment controls on the opener motor unit. Test the door after each quarter turn adjustment to the “down” force and “travel” limit controls until the door closes properly.
- Call a professional: If your springs are broken or your cables are frayed, it’s time to call in a garage door repair professional. Broken torsion springs are extremely dangerous to work on, and special tools and training are required.
Preventative Maintenance: Stop Problems Before They Start
The most effective way to ensure your garage door isn’t slamming is to prevent problems before they start. This is accomplished through some routine maintenance. Here are the steps you should be taking to ensure you get the longest life from your garage door system:
Annual Lubrication: At least once a year, the roller bearings, hinges and springs should all be lubricated. A few drops of light oil on each hinge and a light coating of silicone or Teflon-based lubricant on the springs will do the trick. This will keep friction down and keep rust from forming.Do not lubricate the tracks themselves—the rollers will slip instead of roll, and cause more problems.
Visual Inspection: Spend a few minutes every few months visually inspecting your entire garage door system. Look for rust on springs and cables, fraying on the lifting cables, any loose nuts and bolts, and rollers that don’t spin freely. The sooner you catch wear, the sooner you can replace the parts on your schedule, rather than on an emergency basis.
Repeat the Counterbalance Test: Once or twice a year, you should repeat the counterbalance test we described above. This is the easiest and most effective method for catching spring fatigue before a total failure. If you find the door slowly drifting downward where it once held still, your springs are getting weak and should be replaced.
Get Your Garage Door Fixed Safely and Professionally
Nine out of ten times a slamming garage door can be put down to broken springs or damaged cables, and these are CERTAINLY NOT the kind of things you should be trying to repair or replace yourself! We are all for DIY – doing your own rollers replacement and opener adjustment is fine – but spring replacement is something completely different. Spring replacement is complex repair work that needs to be done by a professional with the right tools to keep the repair from becoming a serious injury.
Do you need garage door repair? Safe and effective spring replacement and garage door repairs are handled by the expert technicians at Two Brothers Garage Doors. Just give us a call today to set up an appointment and we’ll have your garage door in working order again.
Frequently Asked Questions
How do you prevent a garage door from slamming?
Perform regular checks on the condition of your springs by doing annual counterbalance tests, lubricate your springs and rollers, and replace broken springs before they fail completely so your door lowers safely and smoothly.
How do you stop a door from slamming shut?
Perform a counterbalance test and look for signs of spring failure, replace broken springs or call a professional to do it for you, replace seized rollers, or adjust your opener’s force settings depending on what’s causing the slamming.
Why does my garage door bang when I close it?
A slamming/banging sound typically means your springs are broken or are so worn out that they’ve lost their ability to counterbalance the door’s weight, and when you close it, they drop so quickly that they slam into the ground.
Why does my garage door slam shut?
Garage doors slam shut when the counterbalance system is no longer working properly to lower the door safely. This is often the result of broken springs or damaged cables, and the door falls due to its own weight instead of being gently lowered by the tension in the springs.
Learn why your garage door slams shut and how to fix it safely. Discover the causes, perform a counterbalance test, and know when to call a professional.
