(The Wahl correction factor accounts for additional stress in the material due to shear forces, although these forces do not contribute to the spring's torque. These shear forces become significant in designs using a low spring index, which is to say, a relatively thick wire for the coil diameter. The correction factor is applied to scale up the stress S to better predict the fatigue lifetime of the spring.)


(The Wahl correction factor accounts for additional stress in the material due to shear forces, although these forces do not contribute to the spring's torque. These shear forces become significant in designs using a low spring index, which is to say, a relatively thick wire for the coil diameter. The correction factor is applied to scale up the stress S to better predict the fatigue lifetime of the spring.)

I could not be happier with the service from Precision, and Tom, especially. About a year and a half ago I called to have my garage door that was sticking, repaired. Tom came out same day and replaced, adjusted, serviced all moving parts and got it going smoothly. He has since come out within hours of a call to adjust and keep (what might not be the best) door, (originally installed by someone else), operating well. I recommend Precision and Tom with complete confidence.
With garage door installation costs, these numbers also include the actual purchase of the new door and other hardware, including the tracks, adhesives, connectors and fasteners. Keep in mind that if these numbers seem extreme, garage door replacement and upgrades can yield, on average, one of the highest returns on investments for homeowners — with an expected 85 percent.

Correct spring size is determined by factors such as the weight and height of the door. You cannot substitute a different spring and just tighten or loosen the winding to make it balance the load. Why? To maintain cable tension under all operating conditions, the spring must retain about one turn of unspent wind-up at the top-of-travel position, which with the lift drum size and door height predetermines the number of turns of winding at the bottom-of-travel; and furthermore the torsion of the fully-wound spring at the bottom-of-travel must be slightly less than that needed to lift the weight of the door when translated by the lift drums.


Many garage door opener remote controls use fixed-code encoding which use DIP switches or soldering to do the address pins coding process, and they usually use pt2262/pt2272 or compatible ICs. For these fixed-code garage door opener remotes, one can easily clone the existing remote using a self-learning remote control duplicator (copy remote) which can make a copy of the remote using face-to-face copying.

Once the springs are relaxed and loose on the torsion shaft, the lift drums lose their tension on the lift cable, and the cable comes loose. The end of the cable is terminated by a press sleeve, which locks into a ramp on the drum. Different drum styles have a bolt or other method to fix the cable end to the drum. These steel cables are springy and won't stay in place without tension. If my pre-inspection had showed that these cables were worn or frayed, then I would have ordered proper replacements ahead of time from the spring distributor, since this is the opportunity to replace them. Standard hardware-store cable and fittings are not appropriate.
If you've researched this subject at all, you will no doubt have heard that you shouldn't be attempting torsion spring replacement as a do-it-yourselfer. That is generally good advice, so if you have any doubts about your abilities to do risky physical work on your own, hire the job out like everyone else. I found I was capable of doing this work with acceptable risk, because I intelligently understood the techniques, paid careful attention to methods and safety, knew how to use common tools in good condition, properly improvised the special tools I didn't have, and diligently attended to correctly performing a few moments of hazardous manipulation. I learned to do it purely on my own based mostly on bits of advice reluctantly given in Internet forums such as the Usenet newsgroup alt.home.repair. When I first wrote this page in 2002, there was no other do-it-yourself information available on the Web, and it was not until 2005 that reliable information disclosing the techniques started to appear elsewhere (see links below).

If the wires that run from your opener to the photo eyes and to the wall button are exposed, replace them, too. Those wires have probably been in your garage for 10 years or more, and they may be nicked or worn. Newer openers are extremely sensitive and won’t work if a wire is damaged. It only takes about 15 minutes to run the new wire, so it’s time well spent. If the wires are protected inside the wall, you don’t need to run new wire.
Finding the best rated garage door openers is a bit of a challenge. Quality professional reviews are currently hard to come by, and we did not spot any that addressed current models. About the only credible, current, testing-based feedback we spotted was from Wirecutter, and it addressed smart garage door controllers rather than openers. That said, if you would like to add smart features to an existing garage door opener that you are otherwise perfectly happy with, the review is worth a read.
As noted above, set-screw clamping may have distorted the cross-section of the shaft and made it difficult to slide off all the hardware. With the shaft on the floor, it may be possible to restore enough roundness to proceed, using compensating clamping force to the distorted area via a machinist's vise, an arbor press, a hydraulic shop press, etc., on the shaft body. Burrs and other slight distortions on the shaft can be filed off with a hand file or touched with an abrasive wheel on an angle grinder. At some point, the condition of the shaft may just be degraded enough that it ought to be replaced.

Lift cable placement: On the standard residential door mechanism, the loops at the lower ends of the two lift cables loop over the two bottom roller shafts which project from the bottom bracket on the door. The upper cable ends fasten to the drums using one of the methods described above. The drums are positioned along the torsion shaft such that the inner edge of each drum is approximately over the edge of the door. The cable winds onto the drum from outside in, so at the top of travel the cable is winding onto the inner edge of the drum, vertical from the edge of the door where it is looped over the roller shaft. As the door is lowered, the cable winds out to the outer edge of the drum, and thus is a bit out from the vertical, but the cable still falls in the gap between the guide rails and door edge. My cables rub and slap on the rails a bit, but after 30 years and many 10,000s of cycles, they don't seem to have worn at all.


A standard residential door raises 7.5 feet, but since the door goes horizontal this is equivalent to raising the whole door for half that distance, or about 3.75 feet. So if the door weighs, say, 150 lbs, then the energy supplied by the springs is 3.75 * 150, or about 563 foot-pounds. This is like throwing a 50-lb sack of cement up a 11-foot flight of stairs. Or catching a 50-lb sack of cement dropped from 11 feet up.
You'll never ask yourself that question again. Just look at your phone to know for sure. Most smart garage door openers will tell you if it's open or shut. They'll send a message every time your garage door is opened or closed too, if you like. Electric garage door openers provide a huge amount of convenience and safety. Imagine you're in a hurry, it's raining out, you pull out of the garage then press the button on your garage door opener remote. The garage door closes, and you didn't have to get out of your car.
×