We lost our Awning arm over the winter, looked for parts and found the same thing. Have to purchase the entire arm. We paid a mobile awning company in the Tampa area to come out and install the whole thing - As I recall, we paid about $650.00 for the whole experience!
They had two guys, with the right tools and they spent a good 2.5 hours and did a very good job.
Steve & Stacy
2015 Seneca 36FK
2007 Toyota FJC - on the trailer