Lift master 8500 needs door gravity to go down?

[Rusty Bumper]

I put the opener on my 10 x12 door. But I cannot fully open the door as it seems the opener needs gravity do get the door going in the down direction. I need to disconnect the door to lift it the final foot and a half so I can get my camper through. The opener will lift it that far if I program it to do so, but when it comes time to closing the door, well, it does not pull the door. The door needs gravity do go down. When it is all the way up where I need it, there is no gravity to drop the door.

I was thinking I could put some type of spring like my highboy door has in the picture.

Any ideas??
Rusty

 

[HoosierMark]

I have three 8500 openers. Two work great. The third one will start down then stops and goes back up. It goes about as far down as your picture. Sometimes it will work and go down but most times it does not. There is a little flapper attached to the wall that the cable runs thru. I noticed that when it pops open, it reverses. The flapper on the other doors do not pop open like the one. I have not taken the time to check it out but it seems like a similar problem to yours. If I pull on the door as I hit the button then it will close OK, it is just in one spot that seems to stop it. I hope some of the experts on here can answer your question.

 

[gnpenning]

First off that is a bumper spring not a pusher spring.
If your cable tension sensor isn't positioned right the door will start down then will sense no cable tension and stop. Jackshaft openers should have a high lift or pusher springs. Many get away with out but it doesn't mean it's right.
Make sure the the tensioner sensor is adjusted and positioned proper. If it is then pusher springs may fix your problem.

Jackshaft openers turn the spring shaft and can rotate the shaft faster than the springs can keep up at the beginning. This will cause slack in the cable and can cause the cables to jump off the drum. The weight of the door or pressure of pusher springs will keep the cables tight at the beginning of down travel.

 

[ddawg16]

Yep....that is and issue for that type of opener.

You might try reducing the tension on the torsion spring. Combined with the spring you referenced above, it might be enough to move the door down.

 

[Rusty Bumper]

Go penning, what would a pusher spring look like? ....maybe I will just g oo gle it.
Yes, the tension sensor slacks and stops the opener. This is why I do not have the door go all the way up.
Rusty

 

[pattenp]

The horizontal track should be elevated in the back to create a downward slope so the door closes when the opener starts to rotate the torsion bar. If the tracks are close to being flat then the door won't close correctly.

 

[gnpenning]

This should help you.

http://www.liftmaster.com/CatalogResourcesV3/en-us/shared/files/tucmanuals/ISBGDO3800 Door Types.pdf

 

[wssix99]

As implied above, your garage door should be balanced with the spring and its geometry to easily shut/open. The opener doesn't have to exert itself that much, as a result.

So, you either have a door/spring adjustment issue or one of your garage door sensors are tripping. You shouldn't need to make any modifications if your door was properly sized for your opening.

 

[Labradorian]

I Have 2 of these openers also. The issue I was having when my door was open all the way was when the opener tried to close the door sometimes, it would turn the shaft and unwind the cable, and the door would stay in place.

Is yours doing this? or just not doing anything at all?
when you try to close the door does the wireless light blink?

I'm trying to determine if this is a physical problem or programming problem.

My problem was a combination of door balancing with the spring and the also the door was binding when it went all the way to the top.
1. as some others have mentioned, it is imperative(for this type of opener) that when you balance your door with the spring, to leave it slightly on the heavy side, so it should come down on its own when free wheeling but it should come down "SLOWLY" , this will give you the gravity you are looking for. The horizontal garage door rails should have a slight downhill slope(standard design). and make sure your door is not binding when it's all the way up. it has to freely fall as the opener turns the shaft.

with a traditional door opener, the opener is attached to the door and pulls it up and pushes it down. these 8500 only turn the shaft with the spring on it and the door cables. the door needs to "HANG" slightly on the cables in order for the opener to let the door down.

Cheers and good luck

 

[kbs2244]

A quick, dirty, and hopefully temperory fix would be a 4 foot length of closeline.
I like the slanted track idea as a Sat fix.

 

[Rich720]

Mine does this, but only when cold out like 20 or less. Door travels down 2 inches or so then reverses. Very annoying at 5:30 am trying to get to work.
Rich

 

[HoosierMark]

I just searched for the pusher springs on ebay and they were saying a 9 inch spring would work for an 8500 model. This confuses me as my door travels about 2 foot before it reverses itself. So if this spring is only putting pressure at the start of the downward cycle, how will this help? It seems like it would stop applying pressure before the critical point is reached. I assume I must be missing something.

 

[gnpenning]

The 9" if set up proper should work. What is your door height?

What happens it that at start up the cables start "vibrating" and it takes a bit before the slack is enough to trigger the sensor. If you can eliminate the vibration from the start it should work proper.

 

[HoosierMark]

My door is an 8 high by 10 wide. I have an 8 high and 16 wide that works fine and I have another 8 high and 10 wide that also works OK. When I searched ebay that had the different sizes of pusher springs and said the 9" was the size for an 8500 opener.

 

[gnpenning]

That should work for an 8' high.

I know this doesn't make sense to you as all the doors are the same height with the same opener. The cable tension sensor doesn't have to be off much to cause a problem. They have a micro switch that triggers the door to open back up.

The bottom line is they should all have either a high lift or pusher springs at install. While many are installed and work with out it you are asking for issues. All you have to do is look at Medium and heavy duty Jackshaft openers that require the same things for the same reasons. You don't have many homeowners installing these and the installers that do commercial doors understand the needs better.

 

[Rusty Bumper]

I Have 2 of these openers also. The issue I was having when my door was open all the way was when the opener tried to close the door sometimes, it would turn the shaft and unwind the cable, and the door would stay in place.

Is yours doing this?

Yes exactly.

 

[Rusty Bumper]

I think I would need the 27" pusher spring. My door is 12' high and 10' wide. As shown in my original picture, I need to stop the door at the top so almost a full panel is still in the opening. Doing this ensures it will go down every time with out creating slack in the cable and tripping the "cable slack" detector. The unit attempts to close the door up to three times. If the door does not come down after three times, then I thing the light blinks and I have to pull out the manual and figure out how to reset it. It has been awhile.

My track is square at the top and sides so there is no binding. The door will drop at a good clip if less than half the wright is up past the curve. It stays up if I push it up with enough force to get most of the door up around the curve.

A horizontal slop has been mentioned. I have some but was concerned at putting too much where a twist would develop in the track. The horizontal track and the curve are one piece. Is there a suggested slope? 1/4" per 4'??

Rusty

 

[wssix99]

The door will drop at a good clip if less than half the wright is up past the curve. It stays up if I push it up with enough force to get most of the door up around the curve.

Is this with the opener disconnected? It should fall down on its own when only halfway shut and the spring should pull it up when its open more than halfway.


Do you have a picture of the door all the way up, taken from the side? With the door all the way open, the first panel should be wanting to fall down and if the whole thing were not balanced by the spring, the door should come down like a freight train. (If your cables are unwinding, then the physics of your door in the all-the-way-up position are not as intended.)

 

[zkdiesel]

I have some pusher springs I tried with my setup with 8500's. Didn't work out for me but I cut the rails and tilted them at an angle, clears hoist well and provides gravity
If you Wanna try pushers I have two sets I will sell you for shipping price
Pm me

 

[Rusty Bumper]

i have the tight radius curve. This pic is with the opener disengaged and i pushed it all the way open which is needed to get the camper in/out.

I misspoke about the door movement as either i adjusted it in the past or the springs are broke in, but the door stays in place wherever I put it.
Rusty


Sent from my SCH-I545 using Tapatalk

 

[pattenp]

Are your tracks higher in the rear than the front? Place a level on the track, you should have from 1/4 to 1/3 of a out of level bubble slope. It sounds to me that your springs may be too tight. The door should have some weight to it. If you can easily lift it from full closed with no effort then the springs are too tight. The best that I can describe the weight on my door is it's like lifting a 5lb bag of sugar the first couple of feet. As the top panels roll back it gets easier.

Edit : After thinking about it the spring tension isn't going to have a thing to do with the door going down because the opener loads the springs when closing. I don't know what I was thinking. If your door is not moving down once the cables start to unwind you need pusher springs or an increase in the track slope.

 

[wssix99]

I think the fact that the drum unwinds when the motor tries to put the door down (and the door does not move) means there is a problem with the door rollers or the track.

When the drum unwinds, there is zero tension on the door. In that state, the thing should come crashing down. The last panel is canted downward, so that should pull the whole thing downwards in that condition.

I think the door must be bound up or the horizontal tracks may not be level.

 

[Rusty Bumper]

I don't know how I can describe it any better than I already did.
I will be getting push springs.

 

[1500hd]

I think the fact that the drum unwinds when the motor tries to put the door down (and the door does not move) means there is a problem with the door rollers or the track.

When the drum unwinds, there is zero tension on the door. In that state, the thing should come crashing down. The last panel is canted downward, so that should pull the whole thing downwards in that condition.

I think the door must be bound up or the horizontal tracks may not be level.

I totally agree with all above. I have 3 of these openers, I would disconnect the opener and get the door to open and close smoothly. This will take some adjustments to rails and brackets. I have 2” of slope on the horizontal track. My doors open till the bottom panel seal is level with the header. I just feel the pusher springs are covering up the real problem.

 

[gnpenning]

I just came back to this thread and thought it might be a good idea to clear somethings up.

Anytime you have a opener issue you should always disconnect it first and operate the door by hand making sure of smooth operation. This needs to be done now matter what.

After that is done the opener should be run with out the door again checking operation. make any corrections as needed.

Garage door springs are designed to make lifting the weight of the door easier. A door should NOT open and close by itself. A properly balanced door with a wheel above and below the radius of the track should stay in place. a little creep is okay.

As the door opens more weight is on a vertical plane and is HEAVIER as more weight of the door transfers to the horizontal tracks less weight is hanging and it needs less spring tension to move. The whole time the springs are unwinding . When the door is all the way up ( this only applies to standard tracks) most of the tension is out of the springs. The cables should have equal tension on both sides if it was set up right before winding the springs. Now at full opening with very little tension on the springs jackshaft openers going down can turn faster at start up and turn the shaft faster than the springs and weight of the door can keep up. This is when the cables can unwind. Unless the cables unhook from the drum or bottom of the door or break the door can not come crashing down. The cables usually wind around the shaft and bind up stopping any movement of the door.

If you tied a rope to the bottom of the door and pulled down while the opener starts up you can get the door going down until the opener is able to do it on it's own. This is what pusher springs do. Pusher springs need to be under enough tension to keep pushing on the door until there is enough weight on the door for the opener to close without cable vibration. If the pushers aren't installed correctly they are a waste.

As I have mentioned before just because it works without them doesn't mean it is right.

Watch the cable tensioner when the door is going down and the cable will be vibrating enough to trigger the sensor causing the opener to sensor a problem and open the door back up. In many installs you can have the sensor correctly installed and everything else right and still have this problem. Pusher springs are the correct fix. Because I have to warranty my work they all get pushers. I can walk away knowing that the job is done right.

Hope this helps.

 

[Rusty Bumper]

Thanks. I will probably ask you for help if i need it. The springs should be here soon.

 

[gnpenning]

PM if you do and I'll give you a number.

 

[HoosierMark]

gnpenning. Your explanation is exactly how my door works also. I watch the cable tensioner bounce a little then flip up and the door reverses. If i simply grab it as it begins to descend and pull for a few inches it works fine. I had my doors installed first and then added the 8500s. I plan to get the pusher springs and install them myself. I may also contact you if I cannot get enough info for my comfort level.
Thanks for taking the time to paint a clear picture.

 

[gnpenning]

HoosierMark. I was hoping it was clear enough. I've seen enough of these now that I think it is more of an individual opener issue causing the cable to vibrate than a door issue.

All jackshaft openers with standard tracks should have pushers. High lifts, follow the roof line, etc have weight on the cables and should not need them.

Let me know if you need help. As long as you load the pushers as much as you can you should be fine.

 

[pattenp]

All jackshaft openers with standard tracks should have pushers.

Sorry, but I don't agree with that. Some slope to the track may be all that"s needed.

 

[gnpenning]

Sorry, but I don't agree with that. Some slope to the track may be all that"s needed.

No worries. It can work.

If you check out my link in post 7 you will see that even Liftmaster suggests it.
They also suggest raising the rear of the track. Like I mentioned I think that certain openers are what cause the vibration that will cause the door to reverse. Generally little slope won't load the cables enough. The pushers help quell that better in my experience. Your results may very. Raising the rear is a free check for the home owner.

 

[bstar53]

I Have 2 of these openers also. The issue I was having when my door was open all the way was when the opener tried to close the door sometimes, it would turn the shaft and unwind the cable, and the door would stay in place.

Is yours doing this? or just not doing anything at all?
when you try to close the door does the wireless light blink?

I'm trying to determine if this is a physical problem or programming problem.

My problem was a combination of door balancing with the spring and the also the door was binding when it went all the way to the top.
1. as some others have mentioned, it is imperative(for this type of opener) that when you balance your door with the spring, to leave it slightly on the heavy side, so it should come down on its own when free wheeling but it should come down "SLOWLY" , this will give you the gravity you are looking for. The horizontal garage door rails should have a slight downhill slope(standard design). and make sure your door is not binding when it's all the way up. it has to freely fall as the opener turns the shaft.

with a traditional door opener, the opener is attached to the door and pulls it up and pushes it down. these 8500 only turn the shaft with the spring on it and the door cables. the door needs to "HANG" slightly on the cables in order for the opener to let the door down.

Cheers and good luck

I just installed one and it doesnt work at all. Same result. The tension sensor cant be positioned properly because the new worm drive spring tighteners are in the way and if I lower the sensor the door hits it. I dont see a way to elevate the track since it is fixed into a 90 degree L. I have to leave the door down so low it negate the value of having an 8 foot door and if it was a 7 I wouldnt be able to get my truck in at all.
No instructions or support person ever mentioned any of this. Its going tack to the store! JUNK!

 

[TBEVO]

I just came back to this thread and thought it might be a good idea to clear somethings up.

Anytime you have a opener issue you should always disconnect it first and operate the door by hand making sure of smooth operation. This needs to be done now matter what.

After that is done the opener should be run with out the door again checking operation. make any corrections as needed.

Garage door springs are designed to make lifting the weight of the door easier. A door should NOT open and close by itself. A properly balanced door with a wheel above and below the radius of the track should stay in place. a little creep is okay.

As the door opens more weight is on a vertical plane and is HEAVIER as more weight of the door transfers to the horizontal tracks less weight is hanging and it needs less spring tension to move. The whole time the springs are unwinding . When the door is all the way up ( this only applies to standard tracks) most of the tension is out of the springs. The cables should have equal tension on both sides if it was set up right before winding the springs. Now at full opening with very little tension on the springs jackshaft openers going down can turn faster at start up and turn the shaft faster than the springs and weight of the door can keep up. This is when the cables can unwind. Unless the cables unhook from the drum or bottom of the door or break the door can not come crashing down. The cables usually wind around the shaft and bind up stopping any movement of the door.

If you tied a rope to the bottom of the door and pulled down while the opener starts up you can get the door going down until the opener is able to do it on it's own. This is what pusher springs do. Pusher springs need to be under enough tension to keep pushing on the door until there is enough weight on the door for the opener to close without cable vibration. If the pushers aren't installed correctly they are a waste.

As I have mentioned before just because it works without them doesn't mean it is right.

Watch the cable tensioner when the door is going down and the cable will be vibrating enough to trigger the sensor causing the opener to sensor a problem and open the door back up. In many installs you can have the sensor correctly installed and everything else right and still have this problem. Pusher springs are the correct fix. Because I have to warranty my work they all get pushers. I can walk away knowing that the job is done right.

Hope this helps.

I know this is an old thread, but I just had a terrible experience with my liftmaster 8500. Installed by a local business. I hit the button and was walking behind vehicle, it sounded weird so I turned and looked up, it was crashing down, hit my shoulder and I smashed my head into the door and think I need stitches. It looks like it free wheeled and then the pusher spring pushed and it came crashing down. Is this a sensor issue? I messaged the company to have them look tomorrow. But I want multiple input as my two year old son was right next to me and I will do or buy anything to ensure this doesn’t happen again.

 

[racecougar]

The door crashed down or the operator? Was the cable tension sensor installed (properly)?

 

[Walkers]

I know this is an old thread, but I just had a terrible experience with my liftmaster 8500. Installed by a local business. I hit the button and was walking behind vehicle, it sounded weird so I turned and looked up, it was crashing down, hit my shoulder and I smashed my head into the door and think I need stitches. It looks like it free wheeled and then the pusher spring pushed and it came crashing down. Is this a sensor issue? I messaged the company to have them look tomorrow. But I want multiple input as my two year old son was right next to me and I will do or buy anything to ensure this doesn’t happen again.

Most likely you have the door going too far up. This often causes slack in the cables and they can come off of the sheave. Once that happens it is all over except for the crying! The usual scenario is the common pictures you see with the door sitting angled in the frame. It is always best to leave the door stopping down a few inches to maintain some weight on the cables.

 

[CraigStu]

Mine didn't come down but it kept unseating the cables. I could easily see that it was going up too far so I tried to adjust it via the software. I couldn't get it to work and got tired of manually redoing the cables after yet another test. I finally drilled the tracks and installed a bolt w/ a piece of rubber hose on it so the door hit it and stopped where it needed to. It worked great for the next 4 years.

 

[TBEVO]

The door crashed down or the operator? Was the cable tension sensor installed (properly)?

no, i found that the installer took apart the cable tensioner sensor and placed the switch from it in the motor box loose.

 

[racecougar]

Wow.

 

[TBEVO]

Yes, upset, to say the least. I usually install everything myself, but my son was due right around when I was ready for garage doors, so I subbed this out. My head needed staples, too. It is a very large garage door company with 5-star reviews like crazy, and they wholesale to everyone else in the state. After going around a bit, the best I think I can get is the newer style with the built-in cable tension sensor from them and hopefully give them a scare. I am so glad it was me that got hit and not my son.

 

[racecougar]

They should be covering your medical bill. Deleting one of the main safety functions on the operator controlling a door that has the ability to take a life is a pretty big eff up.