Installation Tips
This section is provided as a guide only and is general in nature. You should always contact a local expert to handle most installations. Hangar type and local site conditions may warrant different installation techniques.
Remember safety first and foremost, and if conditions exist where safety is an issue, only have experts handle the part installation. Most local overhead garage doors suppliers and repair technicians can install the parts safely and effectively. Conduct a web search for ‘Doors’ to find installers nearest you.
EXTENSION SPRINGS
These springs are rarely carried by home improvement stores, hardware stores or overhead door companies, as you may have already determined. Most of these springs are used only on Port-A-Port hangars, and are therefore not a common spring.
Useful Life
From the date they were first put into service, springs have a useful life of 7 years and a usable life of between 7 – 12 years. It has been reported that springs have lasted in excess of 18 years, but there is a high level of risk letting replacement go this long.
When new springs are needed
If one spring has broken the rule of thumb is to replace them all. If you choose not to replace them all, you should replace with the same number of new springs on each side. By equalizing the tension with the same number of new springs on each side, your door should remain balanced when opening and closing. If just the broken spring is replaced, an out of balance state will occur, which will lead to additional parts failing. See the Main Door Sheaves installation tips for details.
Prior to a spring breaking, if you are using the “broom stick” method of opening the door, the springs should be replaced. If you can insert a business card in-between any coil of the spring (when the spring is in the relaxed position) the spring has reached its useful life, and all should be replaced.
The operation of the door should be as easy today as it was when new. If it gets more difficult to open each month, and lubrication of all parts has been completed, the springs should be replaced. If the door is as difficult to bring down as getting up, then the problem could be elsewhere. See the Main Door Sheaves installation tips for details.
Never do this with your springs
Never shorten the cable to get extra “stretch” out of your springs. A safety device in the center section of each spring will not allow the springs to be over stretched. Check to be sure the internal safety rod or cable is intact and not damaged. If it is not intact and a spring breaks, the coils could fall onto the contents of the hangar and cause substantial damage.
Never replace a spring when the door is unsecured. Do not rely on the door locking device to hold the door up while replacing a spring. Always secure the door with a come-along, chain or rope attached to a truss frame member. Do not prop the door open with a wood or steel support, as this could fall over. See Spring Installation Techniques below for more detail.
Never leave your aircraft or vehicle in the hangar when replacing a spring.
Spring Installation Techniques
This is the most difficult installation, where safety and door balance are paramount. Techniques for installation will vary by hangar type, site conditions, access and skill level. It is recommended that an expert handle the installation. Residential and commercial overhead door companies are familiar with handling springs. Due to the uniqueness of the springs, overhead door companies rarely carry the springs and it is best to have them on site when they arrive.
Never replace a spring when the door is unsecured. Do not rely on the door locking device to hold the door up while replacing a spring. Always secure the door with a come-along, chain or rope attached to a truss frame member. Do not prop the door open with a wood or steel support, as this could fall over.
General installation techniques (will vary with hangar type).
- You should always install the springs with at least 2 people.
- Never loosen or shorten the cable in any way. If cable replacement is needed, measure distance of existing and replace to exact dimension.
- Remove all aircraft, vehicles and any valuables which could be damaged if a spring falls during replacement.
- With the door up, secure the back of the door to a truss member with a come-along, chain, heavy rope or similar heavy duty securing device. (Never rely on the factory locking mechanism, as it was only designed as a back up to the springs.) This will pull the door further back, relieving additional tension on the springs.
- Loosen the nuts on the rear of the springs all-thread rod, which will further relieve tension on the spring.
- Replace springs and repeat above steps in reverse.
- Tension adjustment will be on the nuts and all-thread rod. This will need to be adjusted monthly for several months until springs cycle through their initial stretch. Springs should then be adjusted at least annually or as smooth operation is required.
MAIN DOOR SHEAVES
Sheaves are the rollers which the cable travels over which connect the main door to the springs.
Causes of sheave failures
Lack of lubrication is one cause for failure. It can freeze and not move as the cable rolls over it. This will create friction making the door difficult to open and close, but more importantly it can fray the cable. If a cable breaks there is nothing to hold the door up, or if the door is down, only the all-thread rod may hold the springs from falling down. However, it is unlikely the all thread bolt will hold. The all-thread rod will likely bend or break depending on age, and the springs could come down on the aircraft wing or other items stored in this area.
The strain of a cable sliding, not rolling, over the sheave could crack or actually break it apart. This could expose the cable to the threads of the bolt holding the sheave in place, possible cutting the cable with the results as described above.
Un-equal spring tension is another cause of failure. After the part is replaced, check spring tension by noting if the door goes up and down smoothly. There should be no twisting, the door must be square to the building and operate with ease. If twisting or out of square is noticeable, the springs need adjusting, tightening or replaced. Refer to the discussion on Extension Springs. Always check to be sure the cable was not frayed as it ran over the broken sheave. If any sign of fraying is detected, replace it immediately. In most cases it is a 1/4″ steel wire obtainable at your local home improvement or contractor supply store.
General installation techniques (will vary with hangar type).
With door up, the cable (in most hangars) will rise above the sheave, allowing removal of the bolt holding it in. Slide out, clean and lubricate (greaseless compound only) the area and replace with new sheave. Remember to check the condition of the cable for signs of fraying. Replace a frayed cable immediately as it is what holds the door up and spring in place.
Where the cable does not raise above the sheave, you will need to relieve tension on the spring assembly to slacken the cable slightly, allowing the sheave to be removed and replaced. In a few instances the cable may need to be lifted with a come-along or similar type device to relieve enough pressure to allow safe removal and replacement.
WING DOOR ROLLERS
There are two sizes of wing rollers, however only the smaller roller is still available. The smaller roller was used on the Standard, Executive, Executive I, and a few early models of the Executive II. Most Executive II and III hangars used the larger roller, that is no longer easily found.
General installation techniques (will vary with hangar type).
The main door needs to be up and the wing door closed for this replacement. You will need a heavy duty post and floor jack (or similar type device) to safely change this roller, along with at least one assistant.
- Remove the two nuts holding the wing door to the roller.
- Secure the wing door so it does not move once the roller is removed.
- Place the post on the floor jack and position under the closest main vertical brace of the cantilever arm closest to the wing door of the roller to be replaced. By slowly lifting on the cantilever arm the front of the hangar will actually rise several inches. With one person holding the wing door, the other person must lift the roller to the top of the guide track and slide it towards the inside of the hangar and out. If the bolt does not clear the wing door, raise the cantilever again just enough for the bolt to clear.
- Immediately place the new roller in the track, slide as before and lower into top of wing door location. Attach new nuts and lower the floor jack/post set up. Release wing door from its secure position. Adjust nuts to allow smooth operation of wing door.
Additional notes
In some cases a plate on the inside of the hangar track will block the ability to slide the roller out. You will need to remove the plate and proceed as outlined above.
To our knowledge no hangar was designed where the external metal siding needs to be removed to slide the roller towards the outside of the hangar.
You should avoid removing the wing door to accomplish the roller change. This is much more work than is necessary. If it is done, new screws should be used to re-attach the hinge to the column or door.