What Makes a Garage Door Grind

What causes it

These are the causes we find most often, in roughly the order we check them.

1. 1

   Stripped nylon drive gear in the opener

   Sectional openers drive through a nylon gear meshed with a steel worm. Once the teeth wear round, the worm chews the remains and you get a coarse grinding from the opener head with little or no door movement to show for it.

   What you can check

   Stand under the opener while someone presses the button. If the grinding clearly comes from the plastic housing rather than from the tracks, and there is white plastic dust on the floor below, the gear is the answer.

   What we do

   We fit a new gear and sprocket kit with fresh grease, then check the door balance, because a heavy door is what wears a gear out in the first place. Where the kit costs more than half a new unit we give you both prices and let you choose.

2. 2

   Rollers with seized or collapsed bearings

   Steel rollers with unsealed bearings pick up dust and salt air. Once a bearing seizes, the roller skids along the track instead of rolling, which grinds, scores the track surface, and puts extra load straight onto the opener.

   What you can check

   Open and close the door and listen for a grinding that travels up the track with the door rather than staying at the motor. Look for bright scoring inside the track and for rollers that are not turning as the door moves.

   What we do

   We replace the rollers with nylon-tyred units on sealed bearings, which run quieter and do not need regular oiling. Where the track has been badly scored we replace that section rather than leave a rough surface to chew through the new rollers.

3. 3

   Loose or stretched chain jumping the sprocket

   A chain-drive opener needs its chain at the manufacturer's tension. Once the chain stretches it rides up the sprocket teeth and skips under load, which sounds like a hard mechanical grind and sends a shock through the whole rail.

   What you can check

   Look along the rail with the door closed. The chain should sit roughly 5mm above the base of the rail at its midpoint. A chain sagging well past that, or slapping the rail as the door runs, is overdue for attention.

   What we do

   We re-tension the chain to specification, replace it where the links have worn oval, and fit a new sprocket where the teeth are hooked. If noise matters, and a bedroom over the garage is common in newer Perth builds, we quote a belt-drive conversion.

4. 4

   Grit and debris in the roller door guides

   Roller doors run their curtain edges inside two steel guides. Sand, leaf litter, insect nests and rust flakes build up in the channel and the curtain edge rasps its way past. It grinds loudest near the bottom, where the debris collects.

   What you can check

   Shine a torch down inside both guides. You will usually see a line of compacted grit or rust scale. Run a dry cloth down the inside of the channel and see how much comes out on it.

   What we do

   We clean out both guides, check the guide spacing against specification, and lubricate with a dry silicone rather than an oil that will simply hold the next lot of sand. Guides spread by an impact are straightened or replaced.

5. 5

   Loose track bolts and brackets

   The vertical tracks are lagged into the timber jamb and the horizontal tracks hang from the ceiling. As the timber dries and the fixings work loose, the whole assembly moves under load and the components grind against each other.

   What you can check

   With the door closed, put a hand on each vertical track and try to move it. Any noticeable rattle or play means loose fixings. Look for shiny halos around the bolt heads, which is a reliable sign of movement.

   What we do

   We re-fix the tracks with the correct fasteners into sound timber, add packers where the jamb has shrunk, re-plumb the verticals and re-level the horizontals. It usually removes half the noise on its own and stops the door working slowly out of alignment.

6. 6

   Failing motor bearings or a dry rail

   The motor's own bearings dry out after ten to fifteen years and begin to howl or grind under load. A rail that has never been greased makes a similar dry scraping as the trolley drags along it.

   What you can check

   Listen while the opener runs with the door disconnected at the emergency release. If the motor still grinds with no load on it at all, the noise is inside the unit rather than in the door.

   What we do

   Where the motor is serviceable we replace the bearings and re-grease. On sealed consumer units that is not economic, so we quote a replacement opener and, if you want, move you to a quieter DC belt unit with soft start and soft stop.