NA: slow garage door opener

GeorgeC

Administrator
Management Council Member
Joined
Dec 5, 2010
Messages
5,503
Display Name

Display name:
GeorgeC
I have two liftmaster 3850s that were installed about 10 years ago. One of them was beginning to open slowly, about 25 seconds. The door travels freely when disconnected and operated manually. I had the torsion spring replaced. It's better now (~17s), but is still slow compared to the other (smaller) door, which opens in 11s. I ran the automatic force calibration, no change. Any other things to check?
 
Does your opener have a mechanical clutch? Maybe check the adjustment or replace?

Hmm. It claims to have a dc motor with a position sensor. Looks like a reduction gear and no clutch if I had to guess from the picture. I think that splined shaft goes straight to the belt pulley.
41D794 Prim.jpg
 
Last edited:
Is there a point at which it slows down and/or speeds up? Or is it consistently slow through it's entire range of travel?
 
How do the two doors compare in terms of effort to lift with the opener disconnected?
Does the slower door "balance" or does it take some effort? You may need to tweek up the springs a few turns?
 
is it slow in both directions?
Only slow going up.
Is there a point at which it slows down and/or speeds up? Or is it consistently slow through it's entire range of travel?
Consistently slow.
How do the two doors compare in terms of effort to lift with the opener disconnected?
Does the slower door "balance" or does it take some effort? You may need to tweek up the springs a few turns?
Both doors balance ok and operate fine manually with the opener disconnected. The slow door has a brand new spring.
 
It sounds like it's groaning on the way up, but I can't figure out why. If something were slipping, I'd expect a normal pitched sound but a longer transit time. Maybe the next step is the kill-a-watt to see if it's pulling more amps than it should.
 
If you end up replacing, I recommend the Chamberlain MyQ openers which have the WiFi remote open/close features as well as video camera if you want it.
 
I bet there's a clutch inside that pulley, and it's slipping.
 
I have 4 remote operated garage doors. I will have to admit I have never timed them going in either direction.

I know what I will be doing after lunch...
 
I bet there's a clutch inside that pulley, and it's slipping.
Wouldn't that reduce the load on the motor, rather than cause it to groan?
041C0076__77400.png
 
Maybe the next step is the kill-a-watt to see if it's pulling more amps than it should.
1.2 amps while opening, sticker says 2.7, so at least it's not burning itself up.
 
The "groaning" is most likely the spring rubbing on the shaft. One word of advice regarding garage doors, do NOT install LED lights in them; they screw up the remote signal. I think I learned that here but I thought it was worthy of being mentioned again.
 
You could swap openers and see if the problem travels with the opener or stays with the door.
 
Owning a couple lift master openers myself, I would agree with the above suggestion to swap openers. I would swap it out for a Genie.
 
The "groaning" is most likely the spring rubbing on the shaft. One word of advice regarding garage doors, do NOT install LED lights in them; they screw up the remote signal. I think I learned that here but I thought it was worthy of being mentioned again.

There are LED bulbs made specifically for garage door openers. Home Depot/Lowes sell them, but they're a bit spendy, I assume they have some sort of additional shielding but can't confirm that.
 
Owning a couple lift master openers myself, I would agree with the above suggestion to swap openers. I would swap it out for a Genie.

I used to think Genie was the top tier opener, but after having had my father replace 2 of them and my sister have issues with one as well (all in under 5 years of new) I don't think they have the same quality they used to. The Chamberlain belt drive units I have in my garage as well as one of the ones in my father's garage (after we got fed up with circuit board failures with the Genie) have been flawless. The belt drives seem to be as quiet as the screw-drive Genies as well.
 
How much lift do you need to lift the door up by hand? May need an extra half turn on the spring.
 
About 25lbs.
 
I haven’t balanced a door in a long time, and never since I got torque springs. I always thought the ideal tension was that the door would hold position at the half-open mark. Maybe disconnect the operator, open the door halfway and see what happens. Something’s going on during the lift: is the belt jumping teeth? Maybe check that tension.
 
Well, now I just hear a relay click and the LED gives me 5 flashes, which either means "landmine has taken my sight" or "Motor RPM is not recognized". Lifetime warranty on the motor, so I guess that's that...
 
Most likely a broken spring on the torsion bar, it could be loose also

loose pulley or sheared off key way on the opener motor shaft.

Clutch adjustment needed.

most obvious suspects
 
Well, now I just hear a relay click and the LED gives me 5 flashes, which either means "landmine has taken my sight" or "Motor RPM is not recognized". Lifetime warranty on the motor, so I guess that's that...
Weird. Tugged on the belt, thinking it might jar the position sensor enough, and sure enough, now it works again, at least for the time being.
 
I had a similar issue on a 4 year old belt drive chamberlain. It eventually just quit, so I got up on the ladder and took it apart. I don't remember how exactly what it was, but I remember thinking "well that's a **** design". I think the tension of the built pulled the transmission output shaft and it eventually wore through the bushing and wiped out the position sensor. Of course the don't sell any of those parts independently..... they're one part number with the motor. It took a bit of convincing with the customer service person, but I did eventually get them to send me a new motor/ transmission assembly under the motor warranty.
 
Weird. Tugged on the belt, thinking it might jar the position sensor enough, and sure enough, now it works again, at least for the time being.
Still working? Mine, a cheapo Chamberlain-branded Home Depot special, is starting to act up in a somewhat similar fashion.

When I disconnect the garage door, the trolley moves in the "up" direction without effort. However, in the down direction there's a slight bit of complaining until it gets to the halfway point and then it really starts groaning from there to the end. When I reconnect the trolley, the groaning goes away if I help it along by pushing down on one of the garage door rollers or on the handle.

Although mine's a chain drive (it's really 1/3 chain and 2/3 cable), where and how did you tug on your belt?
 
Still working, still goes up slowly. I pulled on the belt a few inches from the pulley; I was mainly trying to see if the shaft wobbled, or any evidence that the bearing had eaten itself.
 
The "groaning" is most likely the spring rubbing on the shaft. One word of advice regarding garage doors, do NOT install LED lights in them; they screw up the remote signal. I think I learned that here but I thought it was worthy of being mentioned again.

Been there, done that... Very annoying... But just a slight tweak, do not install cheap, unshielded LEDs from China. I have decent pancake LED lighting in my garage and there is no interference. Having LOTS of light in the garage is important to me!
 
Been there, done that... Very annoying... But just a slight tweak, do not install cheap, unshielded LEDs from China. I have decent pancake LED lighting in my garage and there is no interference. Having LOTS of light in the garage is important to me!
I stumbled upon a Home Depot clearance aisle that had some LED's designed specifically for garage door openers and stocked up on the cheap. No problems whatsoever.
 
When I disconnect the garage door, the trolley moves in the "up" direction without effort. However, in the down direction there's a slight bit of complaining until it gets to the halfway point and then it really starts groaning from there to the end. When I reconnect the trolley, the groaning goes away if I help it along by pushing down on one of the garage door rollers or on the handle.
So in order to do some further debug, I disconnected the chain and ran the motor back and forth a few times. It was definitely slower in the down direction and faster in the up direction. I've no idea why. However, after continuing to run it back and forth several more times it sounded a little better. I reconnected everything and it seems to groan less and no longer detects a false blockage when trying to close the door. Not sure if it was my free-running exercise that helped or if it was because I had to re-tension and re-calibrate everything after re-assembly, though.
 
About 25lbs.

25 pounds seem very high. Mine are nowhere near that. 1 finger lift, and neutral throughout the travel.

Lube the rollers and re-torque (carefully!) the counterspring.
 
Weird. Tugged on the belt, thinking it might jar the position sensor enough, and sure enough, now it works again, at least for the time being.
It seems to have died for good.
 
LiftMaster phone support was mostly useless; they referred me to some local authorized repair companies. I called one and scheduled a "diagnostic", expecting that it would result in "yup, motor's dead, and that's covered under the lifetime motor warranty", but instead, I got a sales pitch from a kid in a minivan who said things like "oh, they don't make those anymore" and "logic board's dead, you need a new opener". Sure, this was unsatisfying and nonsensical and inconsistent with the symptoms, but at least their proposed replacement involved a 2x markup on parts. Told them to pound sand up a rope. Replacement RPM sensors are $15...
 
My garage door opener operates on a long jackscrew and a shuttle to lift and drop the door. Over time dried lubricant caked up in the channel providing resistance and making it harder for the ballscrew and shuttle to travel, especially in low OAT's. Sprayed the heck out of it with PB Blaster to dissolve the old lube, and regreased it with a little moly grease. Lifts like new now.

Took a while for that lightbulb to go on.. (hehe)
 
My garage door opener is getting slow.


woman-opening-garage-door-going-on-jogging.jpg



Might need replacin'...
 
LiftMaster phone support was mostly useless; they referred me to some local authorized repair companies. I called one and scheduled a "diagnostic", expecting that it would result in "yup, motor's dead, and that's covered under the lifetime motor warranty", but instead, I got a sales pitch from a kid in a minivan who said things like "oh, they don't make those anymore" and "logic board's dead, you need a new opener". Sure, this was unsatisfying and nonsensical and inconsistent with the symptoms, but at least their proposed replacement involved a 2x markup on parts. Told them to pound sand up a rope. Replacement RPM sensors are $15...
That sucks.

When my Genie died, their support line said to hold the phone up to the motor and press the button. After that, they said "motor's dead, we'll send you a new one under warranty". When I got it, turns out the motor was fine but the screw drive broke and jammed against the rail. Called them back and they said "oops! We'll send you a new rail assembly under warranty".

So now I have a spare motor.
 
Back
Top