Sliding gate off track: what to do first, and why it happened

A sliding gate is held upright by its wheels on the rail and the guide rollers at the top. Once a wheel has left the rail, those rollers may be all that's holding the gate up, and a sliding gate is heavy: the motors that drive them are built for gates of several hundred kilograms.

1. Keep people, children and pets away from the gate and both sides of it.
2. Don't run the motor. Switch it off at its isolator or plug point if you can reach that without going near the gate. Driving a gate that's off its track can push it further over or damage the motor's gear.
3. Don't try to lift it back. It's heavier than it looks, it can swing as it comes free, and a wheel dropping back onto the rail can trap fingers.
4. Leave the motor engaged. Releasing it lets the gate move freely, which is the last thing a gate off its track should do.

If the gate is leaning or the property is open, call us straight away: the 24/7 emergency repairs across Gauteng are for exactly this. Until then, keep the car and valuables out of reach and keep watch on the gap.

Any of these can do it, and they tend to build on each other:

• Missing or low end stoppers. Centurion calls endstops mandatory, and they must stand taller than the wheel so the gate can't ride over them. ET's manual makes stoppers at both ends of the track a national safety standard requirement, and Gemini warns that a gate must never be able to overrun its track. A gate that overruns its limits with no stopper simply rolls off the end.
• Worn wheels and bearings. A wheel with a worn groove or a failing bearing wobbles and runs badly, and a wobbling wheel can climb out of the rail.
• Debris in the rail. Stones, sand and a lip of soil lift a wheel each time it rolls over them.
• A bent or uneven rail. Gemini's manual warns against bends where the wheels can jam and against any change in track height along its length. A rail knocked by a car, or one that has sunk where water pools, does both.
• Guide rollers that have failed or been set badly. The guides at the top keep the gate upright; if one breaks or binds, the gate leans and the wheels lift on one side.
• A gate that has been lifted. Someone trying to lift a gate off its motor can lift it off its rail too. That's what anti-lift brackets prevent.

A gate that has been dragging for a while will also have been making the motor work harder.

ET also points out that larger wheels roll more easily and hold their line better, and that fixed wheels on a gate that has bowed into a "banana" shape will bind. ET's installers are told to pull the gate with a scale before fitting a motor: the force to start it should stay under 40 kgf, and to keep it moving under 30 kgf. A gate that has crept above that is telling you something before it ever leaves the rail.

If your gate is still on its track but running badly, these are the safe checks that stop it getting worse:

• Keep the rail clean. Sweep out stones, sand and leaves along its whole length, and look for a lip of soil or paving at either end.
• Look at the water. Gemini asks for a furrow that carries water away from the track; a rail that stands in a puddle after rain sinks and rusts.
• Watch the wheels as the gate runs. A wheel that wobbles, squeals or doesn't turn is due for replacing.
• Look along the top. The gate should stand upright between its guide rollers without scraping either side.
• Check the stoppers are there at both ends, and that the gate stops before it reaches them under the motor.
• Don't grease the rail or the gate. Gemini warns that grease collects dirt and turns into a grinding paste.

Anything more, from changing a wheel to straightening a rail, means taking the gate's weight, and that's ours. What a regular service covers is on gate motor maintenance.

Getting the gate back on the rail is the quick part. A repair that lasts deals with why it came off:

1. Lift the gate safely with the right equipment and support it while the work is done.
2. Replace worn wheels and bearings, with wheels whose groove matches the rail.
3. Straighten, level or replace the rail where it's bent, sunk or worn, and clear the drainage.
4. Reset the guide rollers so the gate stands upright, and fit end stoppers and anti-lift brackets where they're missing.
5. Check the rack and the motor: the rack's gap to the gear, and the motor's limits and collision setting.

All our spare parts are genuine, and every repair carries our six-month guarantee on our repairs. Your exact price is set in a free quote before any work starts. No call-out fee when we do the work. If no work is done, a R650 call-out fee applies. More on sliding gates is on sliding gates, and on stopping a gate being lifted on anti-theft brackets.