The top pin was some of scrap used to build. The bends lock in in place. Always meant to replace with a proper pin. The square holes in RR plates might not take a 3/4” round pin. Has lasted lots of jerking. Snaking out logs with chain wrapped around the top. Spin out then play out feet of chain to get going again.
Probably appreciate the improved braking as much as the added driving traction of 4wd.