Office Chair - Replace the Base

The steps for replacing the base of an office chair are as follows:

I. Preparation
Prepare a hammer, preferably a rubber hammer. If using a regular iron hammer, prepare a towel for cushioning. Invert the office chair so that the seat faces downward and place it on a stable ground, ensuring sufficient operating space and preventing the chair legs from scratching the ground. Pay attention to the contact stability between the seat and the ground during this step to prevent the chair from sliding during operation.

II. Remove the Old Base

1. Separate the Seat Cushion from the Base: Use a screwdriver or power tool to unscrew the screws that fix the bottom tray to the seat cushion, usually located in the center or around the base. If the screws are rusty, spray a small amount of rust remover to assist in disassembly. After separation, move the seat cushion to a safe location to avoid bumps.
2. Knock to Disassemble the Base: Hold the chair frame upside down with one hand (ensuring a firm grip), and use a rubber hammer to vertically knock on specific positions on the edge of the base (such as around the connecting shaft). If using an iron hammer, pad a towel between the hammer head and the base to prevent paint damage. The knocking force should be even. Knock around the base multiple times until the base is separated from the chair frame. If the base buckles are tight, you can appropriately increase the number of knocks or use a flat-head screwdriver to gently pry open the gaps to assist in separation.

III. Install the New Base

1. Clean the Connection Surface: Use sandpaper or a wire brush to remove dust, rust, and old glue residue from the connection position at the bottom of the chair frame, ensuring that the contact surface between the new base and the chair frame is flat and smooth. If the connection surface is uneven, use a file to trim it to the matching size.
2. Align and Install: Align the new base with the mounting holes at the bottom of the chair frame and gently press it to make a preliminary fit. Pay attention to the direction of the base (for example, the hole for the gas lift rod should be aligned with the center of the chair frame) to avoid misalignment that may cause abnormal use later.
3. Calibrate and Fix: After installation, restore the chair to an upright position and repeatedly adjust the perpendicularity between the base and the chair frame to ensure that the chair is placed stably without tilting. Use the matching screws to tighten the fixing accessories. The torque should comply with the requirements in the instruction manual (usually 3-5 N·m) to avoid being too loose or too tight. If the base has a gas lift rod, test whether the lifting function is normal.

IV. Acceptance Test
After installation, conduct a functional test: sit on the chair and rock back and forth to check whether the connection between the base and the chair frame is stable; operate the gas lift rod to verify its smoothness; rotate the chair to confirm that there is no abnormal noise or jamming in the base. If any problems are found, recheck the installation steps or replace the accessories.