Our value pick is the Chamberlain PD76EV. It costs about $50 less than our top pick, but it has most of the higher-priced model’s advantages. The PD76EV has the same lift capacity, horsepower, lift system and automation compatibility. However, it doesn’t come with advanced features such as a backup power source, close timer and keyless entry pad. If you can live without those, this opener is a great choice.
The Chamberlain Whisper Drive takes control to a higher level than other models with its door and light automation features. The internal control panel has a sensor for motion-activated lighting. In addition, door closing can be instant or set automatically for 1, 5 or 10 minutes. We give this feature a top-notch rating because, should you forget to close your door, your garage will secure itself.
The low rating on the CS is due to the fact that inwas out of town and my wife called because the garage door wouldn't open. We had repairs to the only other exit, and the CS said because it could be opened manually, it was no emergency. She was stuck in the house for over Sixteen hours. No emergency crew came out. Steve, a tech who came out the first time, fixed the door. It is not his fault CS took their sweet time to help a 45 year customer. I commend Steve. I do NOT have anything good to say about CS.
Spring stretch: When the door is at the top of travel, the spring(s) are hardly wound, but are stretched, so on a single-spring installation this stretch tends to pull the shaft towards the non-spring side. With two springs, the stretch tends to cancel out. This top-of-travel spring stretch, being about 7 or 8 turns of the wire, will thus amount to upwards of about 2 inches on a typical size spring of 0.253 wire. This spreads out to a gap of about 0.020" per coil on a typical 100-coil spring, so the stretch is not very visible.
Garage door manufacturers typically produce garage doors fitted with torsion springs that provide a minimum of 10,000 to 15,000 cycles and are guaranteed for three to seven years. One cycle is a single opening and closing sequence. Most manufacturers offer a 30,000 cycle spring. However, it is important to remember that if the weight of the garage door is increased by adding glass, additional insulation, or even several coats of paint, the life of the torsion spring may be greatly reduced. Additionally, springs at highly humid environments, such as coastal regions tend to have a significantly shorter cycle life, due to the corrosive cracking.