Below is the "cover plate" Jerry mentioned on your axle. Picture is snapshot from a 1952 GMC 1/2 ton that was getting a rear axle swap out in a video I found on the web.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
