High Tension Work

Three Parts Hold All the Energy

A sectional garage door weighs somewhere between 130 and 400 pounds depending on material and insulation. You lift it with one hand because a spring is doing the work, and that spring has been wound up to store exactly that much energy.

Three components carry it. The torsion springs hold it, the lift cables transmit it, and the bottom brackets anchor it to the door. Everything else on the door is along for the ride.

Torsion Spring Replacement

A torsion spring lives on a shaft above the opening, wound to seven to nine turns on a standard seven foot door. Those turns are held only by two set screws biting into the shaft through a cast winding cone.

Replacing one means putting a proper winding bar into the cone, taking the load, loosening the set screws, and unwinding a quarter turn at a time, alternating bars, never letting go of the load. Get the bar seating wrong and it comes out of the cone under full tension.

We replace springs in matched pairs even when only one has snapped. The second has done the same number of cycles and is on the same clock. A standard spring is rated for 10,000 cycles, which is roughly seven years on a normal household. We fit 20,000 cycle springs as standard because the price difference is small and the second call-out is not.

Lift Cable Replacement

The cable runs from the bottom bracket up to a grooved drum on the torsion shaft. Both sides have to wind in step or the door climbs crooked.

Near the water in Long Beach, cables corrode from the inside of the strand outward. The exterior can look perfectly sound while the core is going, so the standard advice to look for visible wear understates how far along one can be. Rust weeping out from between strands is the tell, and by then it is well advanced.

Cables are replaced as a set with the drums re-timed and the door balance tested afterwards. A properly balanced door will sit still when you stop it halfway with the opener disconnected. If it drifts up or drops, the spring is not matched to the door and we adjust rather than leaving it.

Bottom Bracket Replacement

The bottom bracket is the small steel plate at each bottom corner. It holds the bottom roller and it anchors the lift cable, which means it is under full spring tension every moment the springs are wound, door open or closed.

They fail three ways: cracking around the bolt holes, corroding through in the coastal ZIPs, and elongating their holes so the cable end shifts. Replacing one starts by taking tension off the springs in a controlled way. Only then does the bracket come off. Doing it the other way around is how a bracket becomes a projectile, and it is one of the most common serious injuries in this trade.

Off Track and Crooked Doors

If a cable has parted, one side stops being lifted and the door goes up at an angle, then jams hard. Stop operating it. Every further press loads the track sideways and can turn a cable job into a section replacement.

We recover the door, re-set the cables, re-time the drums and true the track. Then we look for why it happened, because a cable does not jump a drum without a cause.

What This Costs

Spring pairs run $260 to $480 fitted, cable sets $180 to $320, bottom brackets $140 to $260 for the pair. If you have a broken spring and old cables, doing both while the tension is already off costs considerably less than two separate visits.

Call (562) 238-4318. If the door is hanging crooked or you can see a gap in the spring coil, do not operate it while you wait.