Tools required:-Machinist Hammer-heavier is better.
Threaded Post should be installed into mechanism prior to mounting mechanism onto chair.
Place mechanism on a solid platform or on concrete floor to install a post.
Before installing Post into mechanism, first slip the Thrust washer (#83, #84) on over the narrow tapered end. Next install the Bell, turning the Bell several complete turns so as not to interfere during seating of the post. Then insert tapered end of Post containing thrust washer and bell into mechanism with the machined long groove (keyway) facing the left when sitting in chair. (The front has the tension spring adjustment handle)
Important-Strike the flat end of Post 2-3 times with machinist hammer with medium to heavy blows, to solidly seat the tapers. Posts which are not tight to the taper can cause accidents and premature wear, rocking, or failure to other component parts. Apply a very small amount of lubricant into the hub plastic liner before installing the base.
Posts are tapered and pressed into the mechanism with 40 lb. pressure for a tight fit. In use it may seat further in. Removal is to press out. This is easier said than done. After removing the mechanism from the chair, you may find that something is in the way of giving a clear view of the post end. Most often, it is the pivot pin.
The easiest method is to go to an automobile shop which has a type of bearing press into which the mechanism can be placed and the post accessed. It will press out with surprising ease proving the power of leverage and gears.
The other method is to punch it out using a hammer and punch. Although not essential, a couple of WD40 squirts at the small end where it tops out of the mechanism, would not hurt. Using a hammer heavier than the common 16oz. household hammer, and a steel punch which has a small enough driving end not to touch the edges of the post, begin the removal with medium heavy blows. Caution! The post is mild steel and the last thing you want to do is to enlarge the taper by punching other than as close to the post center as you can get.
Use Glossary or Tips for other chair parts