Problem with 2016 Sunspot 242 Captain chair

Was out boating and the lift function of the chair failed. Removed the anchoring bolts for the chair and noticed underneath there were a few bolts and some hardware that had fallen out. Was able to figure out where everything went except for a cylindrical steel pin. Oiled all the joints, put it back together, and tested it out. The lift, swivel, and hydraulic function works fine. However, when I raise the seat, it doesn't lock into position and hold. It just sinks back down to the bottom. So I'm guessing that pin has something to do with locking it in place but I cannot figure out where it goes or how to reinstall it.

Any ideas?