Metal guards for the drive shafts were introduced, as shown by the service bulletins below, in mid-1946. They remained an available option, as indicated by this item from the reproduction Special Equipment Catalog 1957-1958.

From the reproduction Special Equipment Catalog 1957-1959

Service Bulletin 778

Service Bulletin 780

Installation Instructions

Scott Sperling sent us photos of the installation instructions.

Todd Paisley found these instructions, indicating the guards were available for the CJ-5, CJ-6, and the FC-150