Shift drum assembly of a transmission

A transmission comprising:

• a plurality of gearing assemblies operationally coupled together to provide a select rotational output from a rotational input of an input shaft to the transmission;
• at least one shift fork configured and arranged to change gearing of the gearing assembly;
• a shift drum housing forming at least a portion of at least one groove guide, the at least one groove guide having a select profile that includes a ramp section, the at least one groove guide configured and arranged to receive at least one shift fork positioning pin of the at least one shift fork, the shift drum housing further having a window, the window including a first side wall and a second side wall;
• a shift cam rotationally coupled to the shift drum, the shift cam having a shift cam tab positioned within the window of the shift drum, the shift cam tab configured to selectively move between the first side wall and the second side wall of the window;
• and
• a bias member configured to bias the shift cam in relation to the shift drum to create a preload force used at least in part to complete a shift when a blocked shift condition of a gear box of the transmission is encountered.

A transmission system for a vehicle implementing a gearbox with shift dogs, the transmission system comprising:

• an input shaft:
• a plurality of gearing assemblies operationally coupled together to provide a select rotational output from a rotational input of the input shaft:
• at least one shift fork configured and arranged change gearing of the gearing assembly;
• a shift drum housing having a window;
• a shift cam rotationally coupled to the shift drum and forming with the shift drum at least one groove guide with a select profile that is configured to receive at least one shift fork positioning pin of the at least one shift fork, the shift cam having a shift cam tab positioned within the window of the shift drum;
• and
• a bias member configured to bias the shift cam in relation to the shift drum to create a preload force used at least in part to complete a shift when a blocked shift condition of the gear box is encountered.

A shift drum assembly for a gear box of a transmission, the shift drum assembly including:

• a shift drum housing having at least one groove guide with a select profile that is configured to receive at least one shift fork positioning pin of a shift fork;
• a shift cam rotationally coupled to the shift drum;
• one of the shift drum and the shift cam having a window, the window including a first side wall and a second side wall;
• another of the shift drum and the shift cam having a tab positioned within the window, the tab configured to selectively move between the first side wall and the second side wall of the window;
• and
• a bias member configured to bias the shift cam in relation to the shift drum to create a preload force used at least in part to complete a shift when a blocked shift condition of the gear box is encountered.