Yes thatís the instructions where it dosent really address the question.
Apparently itís part of the ďquiet runĒ gear assembly. It is not required but is also not necessary to disassemble prior to installation. Iím guessing it adds a little bit of preload to keep the gears meshed in a quiet pattern for them run together. If anyone else has info Iíd appreciate it. Case is fully assembled and ready to drop in my rig!