November 26, 2020

Herman Miller Aeron Tilt lock fix

Here is how I was able to fix my Herman Miller Aeron chair that had a broken tilt lock. Basically the pin broke off the sector gear.I know others have had the issue and might be looking for a cheap Aeron Tilt lock fix. I also found Herman Miller has a newer design on the tilt mechanism that removed this issue. Rather than pay 40 dollars for a new sector gear, I just did a quick hack to fix the broken post on the Sector gear myself.

First I want to mention that I am not a professional, and this post is for entertainment only.  I am not responsible if try to do this and damage anything or injure yourself. I suggest having it professionally fixed. This post is just showing how I fixed my issue. 

Aeron Disassembly

There are lots of videos online of the disassembly, but I will post a couple pictures for reference.

First remove the 2 6MM hex bolts holding on the seat on each side of the chair. Then remove seat.

Aeron Seat removal

Remove 2 Philips head screws from bottom cover.

Aeron Bottom cover removal

Pry open the plastic cover to see the tilt mechanisms.

Pry open cover

Once it was open I could see that the pin broke off the Sector gear. This was why I could not operate the Aeron Tilt lock.

Removing the Rear limit cam and the tilt sector gear was pretty easy. I removed a clip on the Rear limit cam and then after removing the spring from the Sector gear I could pull off both parts.

Parts on Aeron Tilt mech

I did a little looking around at prices for a new Sector gear and found it ran about 40 dollars and came with the cable attached to it. Rather than spend 40bucks, I decided to try to fix it myself. I did this by basically drilling out a hole where the pin was previously located, then I Tapped it with a tap & die set. I had a 10-32 screw in the parts bin so ended up just using that as it was what I had on hand.

Here you can see the fix. Basically the part is just plastic so it was really easy to drill. When I put in the screw I used some Loctite to keep it in place.

Fixing Aeron Sector gear by adding screw

 

When putting git back together you need to line up the arrows on the sector cam and the rear limit cam. Its a little hard to see here, but you can make it out on the Sector gear. I will try to get a better picture and update his later.

lining up arrows on sector cam and rear cam limit Aeron

Then just put it all back together.

I did make a Youtube video of this and posted it online in case its helpful. Here is the link.

Summary of Aeron Tilt lock fix

That was it. I just put the chair back together and the screw seems to be holding the cable in place just fine. I realize the proper way for me to do this would have been to buy a new part. But I had the tools handy and decided to just try this out to see if it works. I will update this if it breaks or I have any more issues. I also did a video on it in case that helps out (link).