How to level garage door rails?

How does a garage door actually hold its own weight?

A garage door is not lifted by the opener — it is lifted by the spring, and the opener only guides it. A residential door weighs 85 to 400 pounds, and the counterbalance holds that weight so the motor only has to overcome friction. That is why springs and cables are professional work while sensors and remotes are not: one group holds the stored energy and the other does not.

Garage door safety covers the balance test and what an unbalanced door does to an opener.

What is the one-minute test everyone should be doing?

The reversal test, monthly, with a 2x4 laid flat in the door's path: it must reverse on contact. If it does not, stop using the opener until it is adjusted, repaired or replaced. It matters because this system fails silently — a door whose reversal has stopped working looks and sounds exactly like one that still does. CPSC recommends inspecting the door and opener every 30 days.

Children, pets and the garage door covers why the standard exists.

At what point should I stop and call someone?

• The door is very heavy by hand with the opener disconnected. The counterbalance has failed.
• You can see a gap in the spring coil, or a cable that is frayed, slack, or off its drum.
• The door sits crooked, higher on one side, or has come off its track. It is still under full tension.
• The door does not reverse on the board test. The entrapment protection is not working.

None of those is calling too early, and the rule worth teaching at home comes from that same federal text: “NEVER GO UNDER A STOPPED PARTIALLY OPEN DOOR.”

Questions that come up next

Does a door that reverses mean something is broken?

No — the opposite. A door that stops and goes back up when it touches something is the entrapment protection doing exactly what 16 CFR 1211 requires. The fault worth investigating is a door that fails to reverse.

Can I disable the photo eyes to get the door closed?

No. That removes the external entrapment protection required since 1993, and it is the protection that exists because of the CPSC child fatality record. If a sensor is genuinely faulty, replace it — it is among the cheapest parts on the door.

Is it safe to use the emergency release with the door open?

The federally required manual text says to use it only when the door is closed wherever possible, because weak or broken springs may allow the door to fall rapidly. A great deal of DIY content advises the opposite.

Should I replace one spring or both?

If the door has two, quote both. The second is the same age and has taken the same number of cycles, so it is next. This is one of the few upsells in the trade that is genuinely honest.

Common mistakes

• Adjusting spring tension to fix the balance. That is counterbalance work. The energy that holds the door up is in your hands while you do it.
• Running an unbalanced door until it fails. The opener is carrying load it was never sized for, so you replace two things instead of one.
• Testing balance with the opener still engaged. The opener holds the door and hides the fault you are testing for.