The Chair Doctor of Grand Junction also repairs office chairs, including the mechanisms. However, cost is a big issue because even simple repairs are frequently more expensive than the chair is worth. If the chair was originally purchased at a big-box store for a hundred bucks or around there, then it is probably more cost-effective to replace it than repair it. If, however, the chair is more expensive than that it might be more reasonable to repair it. Below we give you a primer on some basic parts and repairs you could do yourself, as well as some idea of what we can do for you.
Broken Casters
There are different casters, and different stems on the casters, depending on the type of chair you have. If it has a metal base, then you probably have a short stem with a ring at the top called a grip ring. If the base is wooden, then you have a stem with a button on top (called a grip neck) and a little metal 'keeper' (sometimes it's nylon) called a socket. There are other plates and stems which you can look at on a caster web site like those below.
http://www.greatlakescaster.com
http://www.servicecaster.com/index.shtml
A simple broken caster can be remedied by purchasing a new caster at a hardware store or online. The store will also have the keepers and other pieces you might need. If you can't find something there, search online with the keyword 'caster' and you will probably find a lot of people willing to sell you parts.
Types of Casters
In brief, a hard plastic or nylon caster is used for carpet, and a softer rubber-like material is used for hard surfaces. The best caster out there that we know of is made by Shepherd and is called by the brand name Omega. It is a very good for large heavy office chairs when you don't want to have to fight to move them around.
Casters That Fall Out
If the base of your office chair is wood, and the casters keep falling out because the hole is too big, then we can help. We can fill the hole and drill a new one, but remember we have a $32.50 minimum. If only one hole needs fixed this might be a little expensive, but if all four holes need help then it probably won't cost that much more than the minimum.
There is also a part you can get on other web sites that you can put in place to fix the looseness without bringing the chair to us. Just use a search engine because there are a lot of them out there.
Causes of Looseness
Office chairs get wobbly for several reasons. It might be that the mechanism itself is worn at the pivot points and needs replaced. Another possibility is that there is usually a nylon sleeve (called a hub) that goes on the end of the mechanism inside the base that gets worn. Sometimes there is a washer (called a thrust washer) that gets worn or broken.
The hub and washer are just a few dollars to replace (depending on order minimums from the supplier). The mechanism can cost anywhere from $60.00 or $80.00 all the way up to several hundred dollars to replace. If you are pretty handy with tools you can probably search the web and find the parts you need. If not, give us a call.
One other part that commonly fails on office chairs is the gas cylinder. These can be pretty simple to replace and cost in the neighborhood of $40.00 or so (not including labor), or can be a little more difficult to replace and cost up to $150.00 or more (again, not including labor). Obviously, the more expensive ones are used on more expensive chairs, and the less expensive ones on lower end chairs.
Mechanisms
A mechanism is the part that attaches to the seat, also sometimes called a seat plate. There are two types, manual and automatic or gas cylinder. Manual mechanisms are the ones with the one inch post that looks like a giant screw. Automatic mechanisms or seat plates have levers coming out to the side to adjust the cylinder height or tilt and other functions (depending on the expense of the chair).
Manual mechanisms have a nylon sleeve that goes around the base of the post (inside the hub on the caster/leg section) to ease the stress or wear between the steel post and the hub. This nylon sleeve is called a hub liner. This can wear out and create some wobble.
Automatic mechanisms have parts that swivel (forward and back for the rocking action) in addition to providing a rest for the top of the gas cylinder.
The part with the wheels or casters is called the base. Unless something is broken it usually doesn't need work or replacement.