How To Properly Tension A Chamberlain Belt Drive Opener

Keeping proper tension on the belt drive for a Chamberlain, LiftMaster, or Craftsman will help to ensure a long failure-free operation. It is not uncommon for the spring clip to not be properly released or the spring not properly compressed. This video shows the simple steps to ensure you have the correct tension on the belt drive and can also help to reduce unwanted squeaking.

[@brandona.4600]

Thank u so much! After 10 years in my house finally the garage door seems to operate CORRECTLY!!!! 🎉🎉 it would operate but always jerky when closing! My tensioner spring was still compressed with the clip all this time !!😮 that side by side comparison made things SO CLEAR!!! Once I did that, put it at an inch and a quarter and turned down the closing force, it finally closes on the 1st try 4 times in a row! That’s unheard of for me! People swore it was a misaligned sensor and I knew it was something else but could never figure it out til NOW!!!! Thanks again!!!

[@litho7]

Thanks, my 2 doors and openers were professionally installed by a garage door company and the clips were not released. Seems even some professional installers don’t have proper training. Thanks again!

[@associationbenefit]

Great demonstration. Almost lost track of the spring clip. Found it out in the driveway and didn't know exactly how the tensioner assembly assembled. This video was exactly what I needed. Thanks for posting.

[@edwardmissouri2216]

Thanks for this video. As William Somar already mentioned, the door must be first released from the opener by pulling the T-handle. Very simple adjustment and makes a big difference

[@davemdks]

Great video. Very helpful to see exactly how to adjust the spring that tensions the belt.

[@EverydayHomeRepairs]

Thanks Dave!

[@dipbleu]

You’re my hero. Thank you so much for walking us through each and every important steps!

[@EverydayHomeRepairs]

Thanks for the kind words. Always happy to help!

[@redeye9042]

Good to know that infor dosen"t come in the instuctions. So if I change the belt can I use the old tensioner. Thanks for the video!

[@jamessledd510]

Thank you! The detail of this video helped me realize whoever installed my garage door opener from previous owners, installed it wrong! They had spring, clip, etc on wrong side of tab. Watched the video, 5 minutes later had it fixed and door works great.

[@mitch58100]

Excellent, thank you for mentioning the spring tensioner release, that did the trick! I just installed a new belt and was concerned on how to adjust the tension, releasing that washer did it!

[@georgebluvas6543]

Perfect thanks, my installer also did not release the spring and my door was 'jerking' as it raised and lowered. This video and a couple minutes and it works fine now.

[@EverydayHomeRepairs]

Great George, glad to hear you opener is working as expected now. Way to take maters into your own hands and do a little investigating 👍

[@wendeldickau]

Thanks, just found out the spring tension in my doors were not installed correctly, now I fixed it thanks to you. Thanks so much for the information.

[@EverydayHomeRepairs]

Yeah, seems to be pretty common. Happy to help 👍

[@Ro3Go]

Glad you made this video. Gonna go look at mine in a bit. Keep making them!

[@EverydayHomeRepairs]

Just getting started, thx Luis!

[@alexedward1250]

Great information, thank you, I also subscribed to your channel. The one correction I need to mention is, the Chamberlain Tech support says, the garage door must be released from the opener (using the rope puller on the rail) before making this 1 1/4” adjustment. Best,

[@Tommy-us6fn]

Thank you. Excellent clear directions and easy to follow. Noticed other peoples video did not mention and also had there spring not released in there video.

[@ccyorlando]

Very important and helpful information in this video, thanks a lot for posting

[@velocity800]

Omg!! I have not released that spring on mine for 14years.. thats why it vibrates when accelerating... thanks for your help..👍🏼👍🏼👍🏼👍🏼

[@EverydayHomeRepairs]

I would say you are not along, glad the video helped 👍

[@AdamAdam-nb3ej]

That was extremely helpful, thank you very much for an excellent video..

[@EverydayHomeRepairs]

Thanks Adam x 2 👍

[@Mrbigbooty52]

Thanks for this! Solved my jerky garage door operation.

[@Jeff1960G]

Excellent video! Just installed a new garage door and I did not realize how loose the belt was after only 5 years, but it is all better now!

[@Papawman]

Thank you mission accomplished. Noticed belt has always been loose-ish . Manual not clear on if anything after releasing the spring washer. Their install video stops at spring release. Now it's right... Thanks

[@mjpalmirojr.2466]

Knowledge is power

[@carmena.8786]

Great easy to understand video.

[@pepmyster13]

Thank you. Nice and easy explanation.

[@anthonyclark889]

Thanks brother, this video was A lifesaver.

[@roberthale6980]

Thank you! Thank You! What a big help!!

[@evanarnoldstewart1891]

Big help, thank you!

[@michaelsih2490]

thanks for this video! Very helpful!

[@EverydayHomeRepairs]

No problem Michael, happy to help.

[@br31woodlands69]

Wonderful presentation

[@EverydayHomeRepairs]

Thanks!

[@justoalma9585]

Great video

[@brendanomarra3784]

This helped me out - thank you

[@EverydayHomeRepairs]

Happy to help!

[@jimthomas1759]

Great information. My new installation worked for a second and then something popped and the belt was very slack. Perhaps the drive sections were not seated properly. Going to try a fix like you suggest.

[@eevanskiteboards]

Awesome video, thanks

[@EverydayHomeRepairs]

Happy to help Eric 👍

[@seanmccaughan2567]

Great video. Thank you. Any tricks on how to move the square nut. Even with pliers it won’t move.

[@timivers8823]

Thank you! Needed that.

[@EverydayHomeRepairs]

Happy to help 👍

[@scottcole9069]

Thank you

[@devkin63]

Thank You

[@bobclarie]

Thanks, your videos are very helpful. We just installed a Chamberlain model B4613T on a heavy one piece door. I will check the tension on the belt tomorrow. Question: can you adjust the travel speed on my opener ? I need to slow it down if possible. It starts too fast and causes the door to oscillate for the first few seconds when closing. Thanks, Bob

[@Trail.Blazer902]

Hello, great video i was having a issue with a lose belt my spring was released but it was about 1 3/4 not 1 1/4 ive tighten it and it has fixed my problem. i do have a question about the rail flexing ? is it normal to have some flex in the rail i do have the 8 ft extension. thanks

[@beebeesuliman6086]

VERY WELL DONE. where to obtain the extra parts and manual and and what are the parts . to order from Amazon?

[@mikef5189]

Thanks for this. I installed my own opener about a year and a half ago, at this point, I’ve no idea if I released the spring or not, but I’m thinking NOT. The opener worked great and was super quiet, but last week, the door stopped opening, and when I checked, the belt was hanging because the tensioner nut has completely unscrewed. I can’t imagine it unscrewing with the tension from the spring, but perhaps without it!

[@marth6271]

Mine came emwith a jam nut, so you can “double nut” It to adjustment nut after setting adjuster. You will need a thin 1/2” (13mm) wrench to hold adjustment nut while double nuttin it. Or use your needle nose vise grips, as I did because I didnt want to grind on my nice 13mm spanner that came with one of my BMW scooters. Many years ago. Or a tappet wrench if you happen to be of a certain persuasion….

[@poman911]

If your existing garage opener is a Liftmaster, you can install the Chamberlain right onto the Liftmaster one-piece Tbar rail and belt.

[@Sebastian-dx2xg]

Thnx for the video my belt broke I have one on order so this will help

[@EverydayHomeRepairs]

When you install the new one make sure to check everything over to ensure that whatever caused the failure of the first belt doesn't damage the new one. Best of luck!

[@Sebastian-dx2xg]

It’s close to 15 yrs old so it’s about time.

[@OrangeismyNewGreen]

How much bend should there be on the shaft when the door is closed? Thanks

[@kovacfam1355]

Thanks bro.

[@EverydayHomeRepairs]

No Problem 👊

[@savannahdemissie3518]

Can you do a video on how to change the belt?

[@robertromo4816]

New to your channel, great video no tension. I have a question. Do you know how I can adjust the travel on my Whisper Drive Chamberlain, it only has 2 buttons, a purple one and a black one, all the videos that I've watched have arrows I do not have the arrows, can you help.

[@caymanwest4929]

If you have a squeak on these Chamberlain/Liftmaster belt drive units, check the sprocket cover on the head unit. Remove the cover (two ¼" nuts), clean the inside of the cover thoroughly, spray lithium grease where the cover meets the sprocket (avoiding grease on the belt), and reassemble.

[@MarkSchwanke]

I just installed mine. The spring length is 1 1/4 but it's still having slack sometimes. I worry that I didn't hand tighten enough before I released the spring. Can you do a demo of how you fix the slack when the spring is at the manufacturer suggested tension with spring length of 1.25" on 8ft door.

[@mospeaks6703]

When is it necessary to put a flat head screw driver in the silver washer? I noticed you dident do it when adjusting the spring tension

[@alexedward1250]

I hope this is helpful,

[@arianotero234]

really good ,what about if your rail bends when the door is close ?

[@BiggMo]

A slight bow is acceptable but if it extreme and you’re over compressing the floor seal, you have the down limit setting too low. It’ll shorten the life of the belt, the belt, and put unnecessary stress on the motorhead

[@meanangel4life]

Is there a way to stop the belt from twisting all the time?

[@kartikpanwar9477]

Where can i buy that spring nut bold because yesterday in a installation i lost that spring and it opened up

[@scottjohnson8316]

Hi I have a chamberlain whisper drive and I have that same spring and nut you have. But do I have to pull down on that red cord FIRST to release spring tension before adjusting spring? My spring is slightly over 1.5 inches but feels tight. And when you pull that red cord straight down should you do it with door already closed or in open position?

[@ryanncushway8384]

ordered a replacement belt, both 255" with 20 teeth every 6'. looks to be identical but when i install, there is a massive sag. Followed the directions and seems like there is still about 2" needed to remove all the slack. am i missing something??

[@gohabs1668]

Thanks, just bought the house and all 3 garage doors the ''spring lock'' was not turned, soon I did it everything is fine now,

[@EverydayHomeRepairs]

If I had to guess I bet at least 25% have the lock still installed. Good on you for for checking.

[@JayzBeerz]

where does the washer go once you take it apart?

[@randypq4671]

Just replaced my belt... the new tensioner doesn't have any threading outside the tightening nut. It's as if the belt is shorter than the previous one... but like 3 inches. But it's all working fine... any ideas?

[@feustond]

When I open my door the belt sags really bad on the right side and tight on the other? At rest it's tight on both sides until I open it.

[@scottjohnson8316]

Oh and how do you return the tension? I heard just hit remote and the door moving will automatically set tension again?

[@marvinelder3828]

I am planning to install a new garage door and am planning to replace my Genie with a Chamberlain. Genie is screw drive and gets noisy over a period of time. Hoping the Chamberlain with belt drive will be much quieter.

[@EverydayHomeRepairs]

The Whisper Drive on Chamberlain is AWESOME! You will be very happy 👍

[@TacoGrande007]

When I try to tighten so spring is 1.25 inches like you showed it is way too tight and I am afraid it will break. What am I doing wrong?

[@philbarnes1578]

the belt still sags pretty slightly, the spring might be 1 3/16 inch......I am thinking some sag is normal and it would be better than the belt being tight enough for no sag, is that ok?

[@condor5635]

my belt is just like yours but the new one i cannot even get it into the hole - it is like a quarter inch away which means i need at least another inch to even get threaded piece started. I have the belt super tight so there is no slack! Any suggestions? I don't understand why my new 7 foot belt does not even allow me to start threading it! Thanks

[@condor5635]

I just finished answering the question! Here is what I did. There are 6 belt notches held within the mounting bracket on both ends. That is a little excessive from a physics perspective. Using a small 1/4 chisel - very easy to pry open the locking bracket, all it takes is three chisel hits on each side of the bracket which allows the mounting bracket that holds the belt to release into its individual parts. Then I moved the belt so that 3 notches were engaged and then hammered back the mounting bracket using a bench vise and hammer. Very secure again and 3 notches should be adequate to hold it tightly. That worked awesome to get me the extra inch of length I needed. The other option I would have done (and more preferred) was use a couple of chain links to extend the one that comes on the belt end mounting bracket. Adding 1-2 links would have given me the extra room without taking the mounting bracket apart but I threw out my old bike chain that I replaced 4 months ago! Darn. Anyway adjusting the mounting brackets can always give you a little extra room to either lengthen the below or shorten it if needed. I love solving things! Have a great day

[@iluvlexii4eva]

But what if your spring is compressed and tighten all the way and still have slack, that's my problem?

[@patrickgoodyear5666]

How do you know if you released the spring? If one side of the belt is loose indicating that the belt is not properly on the motor gear, how does releasing the spring do anything to adjust the tension. Ok video, but you don’t actually show the release and adjustment. I’d like to see what happens so I know if I did it correctly.

[@pierrenguyen765]

How do you get the belt not to rotate and twisted? Mine sometimes got twisted and it stopped form opening

[@gokblok]

You likely have a twist in the belt from installation. Pull the cord to release the door from the trolley, then remove the belt and make sure that it's not twisted from drive pulley to Idler pulley. There's no way the belt can twist up on its own during normal use.

[@ramonahumada4]

Hi! I have that same issue, but the metal on top that connects the motor and the tensioner is super tense that it warps up a little. What can I do?

[@EverydayHomeRepairs]

Hey Ramon, could you join our Facebook Group "Everyday Home Repairs Community?" Then you could post a couple pictures and I could get a better idea of your install.

[@ramonahumada4]

Everyday Home Repairs thanks for reaching out. I don’t have Facebook. When the garage door closes that’s when the top metal rod bows under pressure and one side of the belt sags while the is tight. I think it’s just a matter of adjusting the genie!

[@EverydayHomeRepairs]

@@ramonahumada4 can you adjust the lower position? Sounds like the door is completely closing and them some. It might be applying pressure to the concrete and then bowing the rail. Adjusting the lower position is usually a pretty simple process of adjusting set screws or simply using the open/close position arrows depending on the age of your garage door opener. Here is an example kzbin.info/www/bejne/oZ_QZ2agqKaoZrc

[@davidrusk4053]

@@EverydayHomeRepairs that's exactly what I did wrong on adjusting the lower position. I had it going too low and that put pressure to the concreate and then made the rail bow slightly. Thanks!

[@RonHerman-ky5np]

This is a great video Scott as my 6753T didn't come with any instructions and I installed it watching videos.

[@outofmind9222]

Set spring tension to 1-1/4”, opens okay, but when opening the right side ( side opposite spring) gets very slack, what is the cause of this?

[@gokblok]

Try pulling the pin that secures the arm of the door to the trolley, and look for the belt binding on the right side. If you don't see anything, loosen all the tension off the spring and then try to re-tension it without the door attached. Re-attach your arm and secure the pin, see if it changes.

[@gokblok]

Also make sure that the belt has an equal number of teeth on each side from the drive pulley to the link. Could be a couple teeth out and that would give you more tension on one side than the other.

[@NeverLostRoamer]

2:01 do I rotate the nut clockwise or counter clockwise?

[@gokblok]

It depends on what you're trying to do. Counter-clockwise (up) will loosen the tension on the spring, clockwise (down) will increase the tension on the spring.

[@eldstgilmorbarboydodellatb4413]

💚🤘🏿

[@MojobuckProductions]

My threaded rod keeps trying to rotate on me, how can I stop this ?

[@bobman11100]

Use a nut and a lockwasher on the right side, if you have the room on that side.

[@eldstgilmorbarboydodellatb4413]

💚💚💚💚 bookmark/notes : ring that bell 🛎 bell …..ect….tbc….-g-b, bot

[@travisadams4470]

Be careful when you tighten that nut. Mine was seized. I torqued down and that little retain pin @2:15 snapped in half. I had to order another one. Poor design. I would suggest spraying penetrating oil before attempting to turn the nut.

[@jack8356]

My stupid thing came off the track

[@williamhauhn5727]

Rotating mine is no where near as easy as yours??

[@BryanTorok]

I don't understand why there are so many videos on tensioning and replacing garage door opener belt drives. Toothed or cogged belt drives have been use in car engines for valve timing belts for decades and typically last 100K miles. Harley-Davidson has been making motorcycles with belt drive from the engine to the transmission and from the trans to the rear wheel, also for decades. Their claim is that the belts last longer than chains, are quieter and need less maintenance. What am I missing? If the belt doesn't last longer than a chain, why would I want it?