On 2011-10-17, Jim wrote:

top bracket, a box shaped assembly to mate the chair to the gas
strut portion had sheared.

My killer office chair is headed down that road. I gotta disassemble
it this week to discover what is failing. Right now, the loose
side-to-side slack is increasing and I think something is gonna shear.
I figure a stamped pressed metal post/plate something-or-other that's
going. We'll see.

nb