The only replacement parts you need to secure your Thule Vertex 9029 to your hitch are # 908-1240-54 for the M12 Bolt, # 951-1224-54 for the Washer, and # 956122159 for the Lock Washer. There is no replacement nut available, and no need for one. These will screw into the shank/stinger on the bike rack when you install it. You will use the washer, then the lock washer, followed by the bolt. All of these will be on the outside of the receiver tube.
The Thule Snug Tite Hitch Lock and Anti-Rattle... view full answer...