Garage door spring replacement

My southern AZ home is eight years old. The metal garage door is double-car and sectional, with two torsion springs.

Last Sunday I heard a strange "sproing" sound. No idea what that was.

A couple of hours later I went to the garage and tried to open the garage door. Then I realized that the sound had come from a broken spring.

I did some web research and decided to DIY replace the springs. This website was extremely helpful in enabling me to figure out what springs to order.
Introduction to Garage Doors

I bought upgraded springs that (in theory) should last 3x as long as the original springs. They are 60% longer than the original, while the coil wire is 12% thicker.

I placed the order on Monday morning and received the springs (shipped from a Phoenix suburb) yesterday afternoon (one day later.) I am very happy with the sales support and order fulfillment provided by DDM Garage Doors. I managed to install the springs that afternoon, without causing property damage or personal injury.

The dangerous part of this job is untensioning and tensioning the springs. That is well documented in the DIY instructions provided in the above-mentioned website. I bought a 36" length of zinc-plated 0.5" steel rod from Home Depot and used a hacksaw to cut this into two equal pieces. It is possible to buy this tool from the vendor above for $8, which is a very good deal considering I paid ~$7 for the rod and also had to buy hacksaw blades ($5.50 for qty. 5).

However, that tool would ship from the East so in the interest of timely repair, I fabricated my own tool.

 

Yes, after tensioning each spring, I used a small hammer to tap on the rod while inserted in the coil cone, thus stretching the spring end 1/4" to provide the coil spacing as you suggested. Then I tightened the setscrews on the cone.

The test of spring tension is that (when the opener mechanism is released from the door) the closed door stays closed, the open door stays open, and the door at midway remains there.