Aeron Chair Arm rests keep falling – Fix it!

By , March 17, 2014 6:39 pm

The past year my Aeron chair has been bothering me because the armrest will not stay in position. I search all over the web for a solution but it seems that Aeron has switched to a new system and mine is not really supported anymore. I have a knob that you turn to lock and unlock the armrest height. The newer models have a lever that you flip, similar to the quick release on the wheel of bikes.

I finally figured I had nothing to lose so I decide to take apart my Aeron to see if I could fix it myself. As it turn out, it was a super easy fix. The securing mechanism for the arms just needed to be tightened! Why didn’t anyone mention this on all the websites I explored? Here’s a quick and easy step by step.

First, remove the back of the Aeron chair. There are 4 screws securing the backrest and they are easy enough to remove using an allen wrench. Here’s what my chair looked like after the screws were gone and the backrest lifted off.

After 4 screws are removed, the back comes off easily.

After 4 screws are removed, the back comes off easily.


If you look at the arm rest risers, the part that was covered by the backrest reveals a screw used to tighten the assembly. The reason the arm rests won’t stay up is because the assembly has gotten loose. All you have to do is tighten the assembly with the thumbwheel. You’ll notice that even with the thumbwheel tight, there is still some play by the metal plates secured by the hex screw. Use a wrench to tighten this bolt until it is snug. Don’t go crazy or you’ll not be able to operate the thumbwheel afterwards! Here’s a photo of the screw to tighten.

Tighten this screw after you have tightened the thumbwheel.

Tighten this screw after you have tightened the thumbwheel (to the right in the picture)

Well, that’s all there is to it! After you’ve tightened the screw, just put the backrest back on (4 screws) and enjoy your chair with arm rests that actually stay at the height you put it.

I can’t believe how easy it was and how hard it was to find any useful information on the web! I hope this little post will help someone who has similar issues with their older Aeron chair.


24 Responses to “Aeron Chair Arm rests keep falling – Fix it!”

  1. Techguy says:

    Awesome, thanks. You need a torx wrench for mine, but I have the same problem.

  2. Richard says:

    Hi I also have the same issue with the loose armrest. Do you know what size the screw was, or what size and type wrench you used to tighten this? (That armrest screw in the last picture).



  3. song says:

    You know, I didn’t take note of the size. I have a set of hex wrenches and I just found the one that fit. I guess I should have taken note of that. Sorry to be of no help there. If I get a chance soon, I’ll try and take another look.

  4. Alan says:

    what to do if my arm adjuster has a latch? i cant seem to tighten mines

  5. John Eckman says:

    On my model, which has the same thumbwheel but a slightly different back/lumbar support, the hex wrench that worked was a 3/16″ and tightening the armrest itself required a T25 Torx head

  6. Chris McFadyen says:

    I have one with the quick latch for securing it, and the latch on the left armrest keeps slowly… unlatching. I think I’d rather have the old system

  7. song says:

    John, thanks for adding the specifics. I had been meaning to add that info but my “ToDo’s” just got away from me.

  8. song says:

    Interesting Chris. And here I was thinking that the new latch system would be a better solution. I guess the grass is always greener….hope springs eternal..and all that stuff.

  9. song says:

    Richard, It looks like one of my blog visitors has provided the information that you were asking about.

    “the hex wrench that worked was a 3/16? and tightening the armrest itself required a T25 Torx head”.

    I glad someone made up for my laziness. 😉

  10. Ohpinion8ted says:

    Fantastic directions. Worked like a charm. I could kiss you! Thanks so much.

  11. Ash says:

    I just wanted to thank you for posting these instructions. This has been a long time problem with my chair and I was so frustrated about not finding answers on how to fix it. So easy!

  12. Ive had this for the last 7 years and now its finally fixed, awesome

  13. Bonnie Prince Charlie says:

    Hey, this page is the gift that keeps on giving. I just fixed my chair this weekend. By some miracle my drill bit set had one Torx bit — a 25! Thanks much for the instructions.

  14. song says:

    I love it when things just work out. I’m glad it was useful for you.

  15. Phil Gattis says:

    3/16″ Allen worked for me, but the screw inside took a T27 Torx, not T25.

  16. Gary says:

    The ‘new’ lever/latching mechanism is worse than the knob. My chair has never been satisfactorily firm wrt the armrest height adjustments. It will hold the height ok, but the thing has so much lateral slop that it’s irritating. I’ve been meaning to take it apart and see if that’s fixable. Anyone else have/fix this condition with the newer mechanism?

  17. Jason says:

    Thanks so much for posting this. I cranked mine tight. I don’t plan on adjusting it. As long as it stops slipping and I never have to adjust it again, I’m so happy!

  18. Chun says:

    On the lever/latch system you need to put a penny and use a butter knife to hold the bolt to tighten or loosen where the lever is. On the left side it is reverse thread and right arm is normal thread. The left side was loose on mine and I actually overtightened it to where it wouldn’t move up or down so I had to painstakeningly loosen and test.

  19. Mike says:


    I have the opposite problem. My arm rests are stuck. I can turn the wheel a few turns in either direction before it cannot be turned any further. In any case, the arm rest does not move at all. How do I fix this?

    Thank you!

  20. Mike says:

    Figured out the problem 2 minutes after posting my question! Sorry about that!

  21. Stranger says:

    Thanks so much. Our chairs were brought in 1999 and have since went out of warranty. They fixed a couple broken issues for free. But this arm problem has occurred on several chairs. I just spent the morning correcting Arm height complaints and have also issued an order that these chairs can no longer be “borrowed”. Glad I heard your instructions and some others’ comments and assembled tools beforehand.

  22. Marty Patryn says:

    Thanks a million! I have been dealing with this issue for quite awhile.
    This worked like a charm, I really appreciate it.

  23. Lolo wey says:

    Thanks a lot.

  24. song says:

    Thanks for taking the time to post your thanks. :)

    BTW – I discovered a place called Beverly Hills Chairs that has a lot of great Aeron parts and deals. If you need replacement bits, look them up.

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