Howdy y'all! I've got a question about a "loose" driver's side, rear axle. It's moving about just under a quarter of an inch in and out. For context this ranger has 244,000 miles on it. Is this anything to be concerned about? If so, then do I need to replace a "c" clamp in the diff or replace the wheel bearing?

 

Just a guess.
I wonder if the retaining clip has broken away. They're about 1/4" thick.
I've no experience except to open and clean them.