Inline gearbox with fast change gearing

An inline gearbox for a land vehicle that includes an engine having a clutch housing for the transmission of rotational force from the engine to one or more wheels for propelling the land vehicle, the inline gearbox comprising:

• a gearbox housing having a front end, a side and a rear end, the front end adapted to be joined to the clutch housing;
• an input shaft having an axis and contained at least in part within the gearbox housing proximate to the front end of the gearbox housing, the input shaft adapted to receive the rotational force from the engine through the clutch housing;
• a primary gear train contained within the gearbox housing comprising (a) a lay shaft having an axis substantially parallel to the axis of the input shaft and rotationally coupled to the input shaft to receive rotational force from the input shaft, the axes of the input shaft and the lay shaft being spaced-apart to define a forward plane;
• (b) a drive shaft;
• and (c) a plurality of selectively engaged meshed gear pairs respectively mounted on the lay shaft and the drive shaft for transmitting rotational force from the lay shaft to the drive shaft;
• an output shaft having an axis substantially parallel to the axis of the lay shaft and contained at least in part within the gearbox housing proximate to the rear end of the gearbox housing, the output shaft rotationally coupled to the drive shaft to receive rotational force from the drive shaft and for transmitting rotational force to the one or more wheels, the axes of the output shaft and the lay shaft being spaced-apart to define a rear plane;
• a fast-change gear assembly positioned proximate the front end of the gearbox housing to one side of the forward plane and interposed between the input shaft and the lay shaft, the fast-change gear assembly comprising a first fast-change gear and a second fast-change gear meshing with the first fast-change gear, the first fast-change gear and the second fast-change gear having respective first and second fast-change gear axes that are both substantially perpendicularly oriented to a direction on the forward plane substantially perpendicular to the axis of the input shaft;
• the first fast-change gear being rotationally coupled to the input shaft so as to rotate with the rotation of the input shaft, and the first fast-change gear being removable;
• and
• the second fast-change gear being rotationally coupled to the lay shaft so as to rotate the lay shaft upon rotation of the second fast-change gear, and the second fast-change gear being removable.