Liftmaster 8500 Cable Slack

[maljr12]

Relatively new garage owner here - very little experience in working on or troubleshooting these things. I have a Liftmaster 8500 that's been in use a little over a year. A few days ago it started reversing and is giving me the 9 LED blink indicating an issue with the Cable Tension Monitor. When I attempt to close the door (never an issue opening it), about 6 inches into the journey the cable gives just enough slack to trip the monitor. It only happens for a second or two then tightens back up (observed when I hold the CTM in an open position to allow the door to close).

I'm planning on calling Liftmaster about this but prefer to rectify it myself if I can. Is there a way to tighten up that little bit of slack causing this reversal?

I've seen other users saying that just rigged something up to bypass the CTM and I'd rather not do that. If it throws a cable the wife will strangle me with it.

Thanks!

 

[M35A2]

Mine started doing the same thing and after watching it several times it was the first (bottom) panel slightly binding in the curved portion of the track. I got some Blaster door lib and sprayed some in the track in the curve, on all the rollers and hinges and it has been working perfect ever since.

 

[maljr12]

Thanks for the response! I'll see if I notice the panel binding and give that stuff a try.

 

[CraigStu]

I had the same problem. Realized the door was being pulled so far up that there wasn't enough gravity to get it moving downward fast enough to keep up w/ the cable. Tried and tried to reset the max up point and couldn't. Finally installed two stops in the track so the up travel would stop where I needed it to. Fixed the problem for over a year. Then one day we had a power outage I think (?) and I had to redo all the programming. this time I was able to set the max up travel the right way. I left the stops in place as backup.

 

[pattenp]

If the 8500 is on a standard door add pusher springs to maintain cable tension.

 

[Hot Rod Grampa]

The pusher springs are your best option. Lubrication should be an annual thing. You should also disable the opener once a year and test for proper operation. If it is binding, sticking or out of balance this is how you find the issues so they can be remedied. Hope this helps

 

[zkdiesel]

Lubricate the springs also!!!
Pusher springs will help it. Have a set of extras if you wanna try them, otherwise raising the rear of the track so gravity is keeping down pressure on door helps but you will have to custom remake your radius and do some welding

 

[Labradorian]

If the 8500 is on a standard door add pusher springs to maintain cable tension.

^^^^ this or make sure the door is not binding, add some lubricate if required.

Mine was doing this too. This openers need the doors to be near perfect in regards to not binding and rolling freely.

Cheers

 

[maljr12]

Lubricated the tracks, wheels etc and it works perfectly. Thanks for all the advice y'all, I'll be referencing this post often to continue maintaining the doors properly. Greatly appreciated!