Technical Support

Installing LiftMaster 8500 Openers on Low Headroom Doors

Friday, August 10th, 2018 at 5:14 pm by Dan Musick

Customers frequently ask us if it is possible to install the 8500 openers on doors with low headroom.

The answer is “yes,” “no” and “yes” in some situations if you are handy.

The answer is “yes” if, by low headroom, you mean a garage door with the double roller top fixtures.

The answer is also “yes” on some low headroom doors with double tracks if the cable drums are mounted inside the end bearings as pictured below.

These shafts turn the normal direction and the change in cable pitch does not affect the opener.

The answer is “no” if you have the more common type of double low-headroom tracks and the cables come off the tops and insides of the drums.

The main problem with installing an 8500 on this door is that the shaft turns the opposite direction, and the safety sensors would not work. It would be dangerous.

Notice the pitch on the cable above. The second problem with installing the 8500 on this door is that when the door is open, the cable is pitched at a 45-degree angle.

As the door closes, the cable is vertical. The cable tension monitor would have problems adjusting to the angle of the cable.

The answer is”yes” in some situations if you are handy. An 8500 opener will work on these doors if the cables come off the bottoms of the drums as pictured below. However, the answer is “no” if the cables come off the tops of the drums. Installing an 8500 would not be safe because the shaft turns the wrong direction.

When the cables come off the bottoms of the drums, the spring tube turns the same direction as a normal door, and the pitch of the cable stays the same throughout the travel of the door. The challenge here for someone who is handy is creating the brackets for the cable tension monitor and figuring out a way to mount the opener.

On all low headroom doors, we do recommend installing spring bumpers as we explain on our blog titled “How to Install Push Down Spring Bumpers.”


Why Do Garage Door Springs Break?

Friday, August 3rd, 2018 at 4:42 pm by Dan Musick

Garage door springs are made of wire, and they break because every time you open or close the door the wire bends.

This is easy to understand if you have ever bent a small wire or a paper clip to break it.

If you bend the wire back and forth the wire will fatigue and break at about 20 bends.

The same is true of garage door springs, only they last longer. Rather than 20 bends manufacturers normally design them to bend so the door opens and closes 10 to 15,000 times before breaking.

On garage doors with torsion springs, the wire bends around the tube or shaft as the door operates. On garage doors with extension springs, the ends are pulled. This separates and bends the coils as the door operates.

Torsion Spring Pitch

Friday, July 13th, 2018 at 5:29 pm by Dan Musick

We are frequently asked, “Why is one of my garage door springs slinky and the other tight?” Or, “Why is one spring stiff and the other loose?”

The answer lies in the pitch of the spring wire. When a spring is coiled the wire is normally wound at a 90-degree angle from the spool or rod around which the wire is wound. In the door industry there are no hard standards for this 90-degree angle, and, as a result, it varies slightly with every spring.

In reality, from a theoretical view, no two springs are wound exactly the same. One will always have a slightly different pitch. The end result for the customer is that one spring may be perfectly straight when held by one hand in the middle; the other spring may form an upside down “U.” While this may appear to be a problem, a tight spring always has the identical torque rating as a loose spring.

Should I be concerned? No. But here are the answers to your questions.

I hope this helps.


How Do I Replace Garage Door Cables?

Friday, July 6th, 2018 at 12:14 pm by Dan Musick

1. Secure the garage door in the open position.

2. Unplug the opener power cord.

3. Remove the cable from the bottom fixture and drum.

4. Turn the shaft if the cable is too tight.

5. Insert the end of the cable and wrap the cable around the drum.

6. Connect the bottom loop of the cable to the bottom fixture pin, turning the shaft as needed.

7. Remove the tools that support the door and plug in the power for the opener.

More information is available on the DDM Garage Doors YouTube video titled “How to Replace Your Garage Door Cables.”


How Do I Replace Garage Door Springs?

Friday, June 29th, 2018 at 12:26 pm by Dan Musick

1. Measure to assure you have the correct springs.
2. Unwind the unbroken spring or springs.
3. Remove the two center bolts.
4. Mark and loosen the set screws on the cable drums.
5. Slide the torsion shaft to the left and right to remove the old springs and install the new springs.
6. Secure the springs, cable drums and tighten both cables.
7. Wind both springs.

Caution: Replacing torsion spring is dangerous! For more information view the DDM Garage Doors “How to Replace Garage Door Torsion Springs” instructions.

How to Install Push Down Spring Bumpers

Friday, June 22nd, 2018 at 5:28 pm by Dan Musick

Spring bumpers are often needed on residential garage doors to help assist the door to close from the open position when a jackshaft opener such as the Liftmaster 8500 is used.

Without this extra thrust, the cables are likely to peel off the drums as the opener initially turns the torsion shaft, especially if the rollers are dry or if the door binds in the open position.

I tested the amount of force required to compress the 27-inch spring bumper by standing on an analog scale and seeing how much weight I lost.

I weigh about 160 with my tool pouch. When I compressed the spring to its maximum, I lost 60 pounds of my weight.

Two of these bumpers, completely compressed, would require 120 pounds of opener force to open a garage door to its normal position. That is too much. Over time it will create excessive wear on the opener and it could also damage the door.

Rather than compress the bumper all the way, it is safer to limit the compression to 1/3 of the rod length. On this 27-inch spring bumper we limited compression to nine inches.

This gave us a compression of about 30 pounds. Except for some of the lighter, flimsier doors, this should work fine.

These instructions will help you install the spring bumpers.

One spring bumper is for the left side and the other is for the right side. The bracket mounts to the outside of the horizontal track as pictured. Using c-clamps or c-vise-grips, temporarily install the pusher springs as far back on the horizontal track as you can go.

Raise the door and align the bumper with the top left corner of the door.

Go to the other side and install the other bumper as you did on the first side. IMPORTANT: The spring bumpers must always be evenly spaced to prevent cables from coming off the drums as the door opens.

With the opener engaged open the door to its normally open position. If it doesn’t open all the way, measure the length of compression. If it is less than one third the length of the rod, adjust the opener force just enough to get the door to open completely. This door opened completely, but the compression is only eight inches.

Since we want an extra inch of compression, we will move the bumper an inch closer to the top of the door. To do this mark the necessary distance needed for moving the bumper. Here we marked an inch.

Next, move the bumper one inch and grip it into place.

Adjust the bumper as needed to align it with the top corner of the door.

Drill two holes with a 3/8 inch bit. Drill at the ends of the slots closer to the door.

Secure the bracket with a 3/8 inch bolt and nut.

Drill the second hole at the end of the slot closer to the door. Should the nut come loose in the future the bracket will not move. This will prevent the cables from coming off the drums when the door opens.

Secure the bracket with a second 3/8 inch bolt and nut.

Repeat this process on the opposite side. Adjust the bracket as needed, align the bumper with the top corner of the door, and secure the bracket with two 3/8 inch bolts and nuts.

There are some applications where the horizontal tracks are not long enough for mounting a spring bumper. When this is the case, you can move the bumper further into the garage by adding two-inch angle to the inside ends of the horizontal tracks.

The coils rattle as they are compressed. For quietness lube the entire length of the rod with a 40 weight oil or a light grease.

If we can help with any questions, please contact us.

Overhead Door Preventive Maintenance & Inspection

Friday, June 15th, 2018 at 3:26 pm by Dan Musick

The following checklist is for maintenance technicians who can work from some type of lift. If you are working from a ladder you will alter some of the steps. Exercise caution when servicing any type of overhead type door as there are many dangers in servicing them.

For safety, close the door and turn off the power to the operator is one is present.

Maintenance from the Floor

Begin maintenance at the bottom left side of the door.

• Inspect the seal across bottom of door.
• Inspect bottom of jamb to confirm that it is straight and secured to floor.
• Inspect bottom of vertical track angle to confirm that it is straight and secured to jamb.
• Inspect bottom of vertical track to confirm that it is straight and secure. Check for loose track bolts and nuts.
• Inspect bottom of cable for frays, corrosion and rust.
• Inspect bottom fixture for damage from section being hit and for scrape marks from misalignment.
• Inspect bottom roller and confirm that the wheel can be turned with fingers. Check for wear.
• Lubricate the bottom roller stem, wheel and bearing.
• As you spray with your right hand, with your left hand inspect the next roller up for wear and to make sure it turns inside the track.
• Inspect the first end hinge from the bottom for cracks, wear, bends, and damage. Check the screws to make sure they are tight. Lubricate the first end hinge and roller from the bottom. Spray both hinge points, and spray lube the roller stem, wheel and bearing.
• Repeat this process as you work your way up the left side of the door going as high as you can, usually eight feet. Inspect jamb, track angle, track, hinges, rollers and fasteners as you go. Lube and each roller and end hinge as you go up the side of the door.

• Move to the first row of inside hinges. Starting at the top lubricate the hinge and inspect for loose screws, wear and damage.
• Move down the door lubing and inspecting each hinge.
• Move to the right and, starting at the bottom, lube and inspect each hinge as you rise to the highest hinge you can reach.
• Move to the next row of hinges, and starting at the bottom, repeat this process until all the hinges are inspected and lubricated.

• When you reach the right side of the door, move up or down and inspect the jamb, angle, track, cable, bottom fixture, hinges, rollers and fasteners. Lubricate the hinges and rollers.

Maintenance from the Lift

As you rise on the left side of the door, inspect the jamb, angle, track, cable, hinges, rollers, top fixture, and fasteners. Lubricate the center hinges, end hinges, and rollers.

Rise to the Left end of Torsion Spring Assembly.

• Inspect the end bearing plate to assure it is plumb and secured to the jamb.
• Inspect the end bearing for wear.
• Inspect the shaft for wear and assure that it is straight.
• Inspect the cable for frays. Check to assure the end of the cable is properly seated in the slot of the cable drum, and that it follows the outside groove of the drum.
• Inspect the drum for cracks and wear. Check to assure the neck of the cable drum is touching the race of the end bearing.
• Inspect the key to assure it is properly seated between the drum and shaft keyways. Tighten the cable drum set screws.
• Lubricate the end bearing on both sides and allow some of the oil to get between the shaft and the race of the bearing.
• Moving to the right, inspect the winding cone but DO NOT TOUCH THE SET SCREWS. (These rarely come loose, and it is good to avoid the danger of accidentally turning a set screw the wrong direction.) Never touch a set screw without first inserting a winding bar into the winding cone.

Move to the Center of the Torsion Spring Assembly.

• Inspect the spring anchor brackets to assure they are plumb and secured to the pad. Never replace or secure a pad or the spring anchor bracket without first unwinding the spring.
• Inspect the stationary cones for cracks.
• Inspect the bearings for wear.
• Inspect both sides of the coupler, keys, and keyways for wear.
• Tighten the coupler set screws. Check to assure there is a lock nut on the setscrews that are tightened to the key and tighten these lock nuts as needed.
• Lubricate the bearings and the shaft inside the bearings that are inside the stationary cones.
• Lower the lift, inspect and lubricate the upper inside hinges.

Move to the right side of the Torsion Spring Assembly.

• Inspect the cable, drum, end bearing & plate, shaft, and key. Tighten the cable drum set screws and lube the bearing as you did on the left side. Inspect the spring winding cone of the torsion spring but DO NOT TOUCH THE SET SCREWS!

• As you lower the lift on the right side of the door, inspect the upper jamb, angle, track, cable, hinges, rollers, top fixture, and fasteners. Lubricate the center hinges, end hinges, and rollers.

If the Door has an Operator

• Tighten and check all the collar and sprocket set screws.
• Tighten and secure drive coupler or drive chain and sprocket as needed.
• Lube the chains and bushings.
• Test the operator clutch and adjust as needed.
• Adjust the operator travel or limits. If you are servicing a door in a part of the country where there is snow in the winter, be sure to leave some coast as the operator ends its close travel.

Check the Overhead Door Balance

• Disconnect the door from the operator and check the door balance. Adjust the springs as needed so the door will stay at any point in its travel without having to hold it. Re-engage the operator.


Free Garage Door Hardware

Friday, June 8th, 2018 at 5:20 pm by Dan Musick

On our Standard Garage Door Torsion Springs page we include a special offer for free hardware or free winding bars.

Since we started this we have had a number of requests for substitutions.

For example, someone purchasing one of our torsion spring conversion kits will sometimes ask to deduct the value of the free hardware from the kit.

We have also had requests for part substitutions, for example offering the better Freeway brand end bearings which cost significantly more than the standard bearings that come pressed into the end bearing plates.

As much as we like to help customers get the parts they need, we regret that we are unable to substitute parts.

Obsolete Garage Door Seals

Friday, April 20th, 2018 at 6:51 pm by Dan Musick

Over the years a number of customers have asked us to if we carry a seal to match what they have on their door. All of the weatherstripping we carry is on our Garage Door Seals page.

Below are a number of seals that are no longer available. If the seal you need is pictured below, we suggest you search for your seal on Google Images. Just drag a picture of your seal into the search box and a number of images will show up in the results.

Below are pictures of images that we cannot find, and which appear to be no longer available.



How to Replace TorqueMaster One Springs

Friday, February 23rd, 2018 at 7:11 pm by Dan Musick

This week we posted our new TorqueMaster Spring Replacement video on YouTube.

This was created to use in conjunction with our written Wayne Dalton TorqueMaster Torsion Spring Replacement instructions with pictures and animated gifs.

It took a while, but I believe the quality was worth the wait. Do-it-yourselfers can now watch the video and determine if they want to buy TorqueMaster Springs and replace them without having to pay, in some cases, outrageous fees to have an outside contractor do the work.

I wrote the script, and Chris David shot and edited the video. Way to go, Chris!

We spent a lot of time showing how to remove the plastic liner from the tube. Over the years this has been a problem with many of our customers.

At DDM Garage Doors we wish those of you who view the video all the best.


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