Door Alignment After a Vehicle Impact

Purpose

A vehicle hits a garage door maybe twice a year in a small shop's book, and it is the call most likely to produce a repair that looks finished and is not. The visible damage is a dented section. The damage that matters is behind it: a bowed vertical track, a bent bottom bracket, a shaft knocked out of true, a cable jumped off its drum, and a jamb pushed off plumb.

This standard fixes the order of assessment so that alignment is measured before anything is straightened, the replace gate is applied to parts that cannot be trued, and the as-found condition is documented well enough to support a claim the shop did not create.

Scope

Covers assessment, alignment and disposition after a vehicle strikes a residential or light commercial sectional door, whether the door still runs or not.

Does not cover re-railing a door whose rollers have left the track, which the door off track recovery SOP owns, or replacing a damaged section, which the panel replacement SOP owns. Does not cover counterbalance repair; a spring or cable finding here routes to the cable off the drum correction standard or the torsion spring replacement SOP. Does not cover a vehicle still trapped behind a door that will not open, which the vehicle trapped inside response SOP owns.

Roles and responsibilities

Procedure

1. Stop the door from being operated, then de-energize the operator. Tell whoever is present not to press the button, unplug the operator and keep the plug where you can see it, working under the cord-and-plug provision at 29 CFR 1910.147(a)(2)(iii)(A). Acceptance: operator unplugged, plug in your possession, and everyone told out loud that the wall button is out of service. Wrong looks like a helpful customer running the door once to show you what it does. Stop rule: none, this happens first every time. Hazard: an impacted door can be held up only by a bent track or a jammed roller, so nobody stands in the opening while you do this, and nobody walks under the door to reach the plug.

2. Restrain the door where it stands before the vehicle moves. Clamp both vertical tracks under the bottom roller if the door is down, or support it on the rail and clamp above a roller if it is part open. Acceptance: locking clamps set on both tracks, and the door does not move when you push it. Wrong looks like a single clamp on one side, which lets the door rack and drop the free side. Stop rule: if the door cannot be restrained because the track is destroyed on one side, it gets propped from below with rated stands before anything else happens. Hazard: never move the vehicle away from a door leaning on it until the door is independently supported, because the car may be the only thing holding the door up.

3. Record the as-found state before you disturb anything. Photograph the full opening from outside and inside, then each damaged component close up with a tape in frame for scale. Acceptance: at least one overall photograph from each side plus one per damaged component, and a written list naming each component and its condition. Wrong looks like four photographs of a dented panel and nothing of the track, bracket or drum. Stop rule: do not begin any disassembly until the photograph set is complete, because once the track comes off nobody can prove what it looked like. Hazard: none at this step, the door is restrained and you are working with a camera.

4. Check the counterbalance and both cables before you assess anything else. Look for a cable off its drum, slack on one side against tension on the other, a gap in a torsion spring, and a bottom bracket pulled or twisted. Acceptance: both cables seated in their drum grooves and taut, springs continuous, both bottom brackets square and tight. Wrong looks like one loose cable and a technician who assumes the impact only bent sheet metal. Stop rule: any cable or spring finding stops the alignment work and routes to the counterbalance SOPs, because measuring track on a door whose weight is unsupported on one side gives a reading that means nothing. Hazard: the bottom bracket is under full cable tension even on a closed door, so no fastener on a bottom bracket is loosened at any point in this procedure.

5. Measure vertical track plumb and spacing at three heights on both sides. With the door closed and clamped, hold a level on each vertical track and measure the track-to-door-face dimension near the floor, at mid-height and just below the horizontal curve. Acceptance: the track-to-door dimension matches the track manufacturer's published figure for that door thickness and roller stem length, and the three readings on a given side agree within 1/8 in. Wrong looks like a track that reads correct at the top and 3/8 in wide at the height of the bumper. Stop rule: any side whose three readings spread more than 1/8 in is out, and the reading is recorded rather than corrected on the spot. Hazard: keep your hands off the track flange edges, which are sharp on a struck track, and wear cut-resistant gloves for this step.

6. Roll the shaft and sight the horizontal track before you decide anything. Turn the torsion shaft slowly by hand with the door restrained and watch the drums, then sight along each horizontal track from the header back. Acceptance: drums that turn without visible wobble, and horizontal track straight through its length with no dip at a hanger. Wrong looks like a drum rising and falling as the shaft turns, which is a bent shaft, or a horizontal track kinked where the door's top section pushed it. Stop rule: a bent shaft and a kinked track are both replacement parts, not adjustment parts, and neither gets straightened; write them on the list and stop assessing that side. Hazard: turn the shaft by hand only with the springs at rest and the door clamped, and never grip a shaft near a set screw or a drum with a bare hand.

7. Apply the replace gate component by component, and write the reason next to each. Work the list: sections, hinges, rollers, brackets, track, shaft, drums, cables, jamb, header. Acceptance: every damaged component carries a disposition of replace, realign or serviceable, with the observed cue written beside it. Wrong looks like a list that says "straighten track and panel". Stop rule: a creased or kinked end stile, elongated hinge fastener holes, a bent bottom bracket, a bent shaft and a kinked track are all replace, and the shop does not put them back in service straightened; if the customer declines a replacement on any of those, the door does not go back into powered service and that goes in writing. Hazard: none at this step; it is a decision made with a clipboard beside a restrained door.

8. Restore only after realignment, then prove the door three ways before you leave. Fit the replacement parts, reset vertical track to the manufacturer's dimension, remove the clamps, cycle fully by hand, then re-engage the operator and cycle under power, then run the balance and reversal checks. Acceptance: full manual travel with even effort and the bottom rail meeting the floor evenly, and under power the door reverses on beam interrupt and reverses to full open on a 1.5 in 2x4 laid flat, re-tested on a 1 in object per 16 CFR Part 1211 if it only just reverses. Wrong looks like a door that runs under power but binds by hand at the impact height. Stop rule: any of the three checks failing leaves the door disengaged and the customer told not to use it. Hazard: this step puts motion back into a door somebody drove into, so the bay is clear of people and vehicles first, and the force settings are re-verified rather than assumed, because a force turned up to push through the damaged travel will no longer reverse on a person.

The record this produces

• Photograph set from step 3: overall from both sides, plus one per damaged component with scale.
• Counterbalance findings from step 4: cable seating, spring condition, bottom bracket condition, each side named.
• Track measurements from step 5: three readings per side, with the manufacturer's published dimension they were compared against.
• Shaft and horizontal track findings from step 6.
• The disposition list from step 7: every component, its disposition, and the cue that decided it.
• Final verification from step 8: manual cycle result, powered cycle result, both entrapment test results with the object size used.

The adjuster reads the photograph set and the disposition list. The next technician reads the track measurements to know what was replaced and what was left. If the door is struck again, the dated measurements are what separate new damage from old.

Worked pass: 16 ft by 7 ft double, reversing SUV, one gate fails

Low-speed reverse into the right half of a double door. The customer says it still opens.

Step 1 unplugged the operator and the plug went in the technician's pocket before the homeowner could demonstrate anything. Step 2 clamped both vertical tracks under the bottom rollers; the vehicle had already been driven clear, which is noted because the as-found position was disturbed before arrival. Step 3 produced 11 photographs: two overall from outside, two from inside, and one each of the bottom section crease, the right bottom bracket, the right vertical track at bumper height, both drums, and the header.

Step 4 found the left cable seated and taut and the right cable slack with a full wrap off the drum. That routed the counterbalance work to the cable off the drum correction standard, and it also meant step 5's measurements taken as found would have been meaningless, so the cable was re-seated and tensioned under that SOP before the track was measured.

Step 5 failed on the right side. The track-to-door dimension read 1-3/8 in near the floor, 1-3/4 in at mid-height where the bumper struck, and 1-3/8 in below the curve. The spread of 3/8 in between the largest and smallest reading is three times the 1/8 in gate, so step 5's stop rule was taken: recorded, not adjusted. The left side read 1-3/8 in at all three heights and passed.

Step 6 turned the shaft with no visible drum wobble, so the shaft was serviceable. The right horizontal track sighted straight. Step 7 wrote the dispositions: bottom section replace, creased end stile; right bottom bracket replace, visibly twisted; right vertical track replace, out of plumb by 3/8 in at mid-height and not to be straightened; right cable replace, kinked where it came off the drum; rollers on the right side replace, flat-spotted; shaft, drums, horizontal track and left-side hardware all serviceable.

Note what the gate prevented. The right vertical track could have been pulled back to 1-3/8 in with a bar in about ten minutes, and it would have measured correctly that afternoon. A track bent past yield and pulled back carries a memory of the bend, the roller finds it under load, and the door binds at that height six months later on a service call nobody connects to a car. Step 8 ran only after the replacement track and section went in: the door cycled evenly by hand, reversed on beam interrupt, and reversed to full open on the 1.5 in 2x4 without needing the 1 in re-test.

References

• 16 CFR Part 1211, the CPSC safety standard for automatic residential garage door operators, which sets the entrapment protection requirements and the 1 in test object used in step 8.
• 29 CFR 1910.333(b)(2) for electrical work practices, and 29 CFR 1910.147(a)(2)(iii)(A) for the cord-and-plug provision relied on in step 1.
• Track and hardware manufacturer's published vertical track dimensions for the door thickness and roller stem length in use; these govern step 5's acceptance figure.
• See related: the door off track recovery SOP for re-railing, the panel replacement SOP for section swaps, the cable off the drum correction standard for step 4's routing, and the door balance test standard for the balance check in step 8.