By a wide margin, the most common garage door problem is broken torsion or extension springs. Springs absorb almost all of the door's weight and cycle every time you open or close — they're consumables with a finite life of around 10,000 cycles. The second most common issue is misaligned or dirty safety sensors, which prevent the door from closing. Worn rollers and hinges (causing noisy operation), frayed cables, remote battery failures, and motor gear strip-out round out the top five. Most of these are preventable with a yearly service that includes lubrication, hardware tightening, balance testing, and a safety check. Annual servicing is much cheaper than emergency repairs.

You should not replace garage door springs yourself. Torsion springs hold enormous stored energy — a single spring can exert hundreds of kilograms of force when released, and DIY replacements are responsible for serious injuries every year in Australia, including broken bones, lost fingers, and worse. The job requires winding bars, the correct spring rating for your door's weight, and an understanding of how to safely tension the spring without it slipping. A licensed technician will replace a single torsion spring for $250–$450 including labour and a quality spring, usually in under an hour. Extension springs are slightly less dangerous but still risky. Spend the money — it's not worth the hospital visit.

Replacing a garage door spring in Australia costs $250–$450 for a single torsion spring fully fitted, or $400–$700 if both springs need replacing (recommended, since they wear at the same rate). Extension springs are slightly cheaper at $180–$350 per pair. The price includes the spring itself, callout, and labour, and most jobs are done in 60–90 minutes. Heavier or oversized doors with larger-gauge springs cost more — sometimes $500–$800 a side for double doors with timber panels or insulated steel. Always replace springs in pairs even if only one has snapped; a mismatched pair causes the door to lift unevenly and shortens the life of the new spring.

Torsion springs sit horizontally above the door on a metal shaft and twist (torsion) to lift the door. They're more durable, balance the door more smoothly, and are now the industry standard on most modern Australian sectional and roller doors. Extension springs run vertically along the horizontal tracks on either side and stretch (extend) to provide lift. They're cheaper but wear faster, are noisier, and can fly across the garage if they snap without a safety cable. Torsion systems last longer (15,000–20,000 cycles vs 10,000 for extension), are quieter, and offer better balance — which is why nearly every new sectional door in Australia ships with torsion springs.