Snowmobile having a gearbox

A snowmobile, comprising:

• a frame;
• at least one ski connected to the frame;
• a rear suspension assembly connected to the frame;
• a drive track disposed around the rear suspension assembly;
• an internal combustion engine supported by the frame, the engine comprising a crankshaft;
• a continuously variable transmission (CVT) operatively connected to the crankshaft, comprising:
• a drive pulley operatively connected to the crankshaft;
• a driven pulley;
• and
• a transmission belt interconnecting the drive pulley and the driven pulley;
• a countershaft connected to the driven pulley of the CVT;
• a forward drive gear mounted to the countershaft;
• a gearbox comprising:
• a first shaft;
• a second shaft extending parallel to the first shaft;
• a plurality of gears mounted to the first shaft, including:
• a plurality of first transmission gears;
• and
• a driven gear engaging the forward drive gear;
• a plurality of second transmission gears mounted to the second shaft,
• each of the first transmission gears being in constant mesh with a corresponding one of the second transmission gears to form a plurality of gear pairings including a high gear pairing and a low gear pairing,
• for each of the high and low gear pairings:
• a given one of the first and second transmission gears being in selective free-spin engagement with a corresponding one of the first shaft and the second shaft to which the given one of the first and second transmission gears is mounted,
• an other one of the first and second transmission gears being in fixed engagement with a corresponding one of the first shaft and the second shaft to which the other one of the first and second transmission gears is mounted;
• and
• a housing enclosing the first and second transmission gears therein and rotatably supporting the first shaft and the second shaft, the countershaft partly extending within the housing and rotatably supported thereby,
• a configurable portion of the countershaft extending laterally between the forward drive gear and an inner wall of the housing,
• a configurable portion of the second shaft being laterally aligned with the configurable portion of the countershaft;
• a driveshaft coupled to the second shaft of the gearbox, the driveshaft being operatively connected to the drive track to propel the snowmobile;
• and
• a shifter operable by a user for selectively operating the gearbox in one of a high gear, a low gear and a neutral gear, such that:
• when the gearbox operates in the high gear, the shifter engages the given one of the first and second transmission gears corresponding to the high gear pairing to cause driving engagement thereof with the corresponding one of the first shaft and the second shaft;
• when the gearbox operates in the low gear, the shifter engages the given one of the first and second transmission gears corresponding to the low gear pairing to cause driving engagement thereof with the corresponding one of the first shaft and the second shaft;
• and
• when the gearbox operates in the neutral gear, the shifter is disengaged from the first and second transmission gears so that the given one of the first and second transmission gears of each of the high and low gear pairings remains in free-spin engagement with the corresponding one of the first shaft and the second shaft,
• the snowmobile being configured according to one of a first configuration and a second configuration, wherein:
• in the first configuration:
• the forward drive gear is rotationally fixed to the countershaft;
• the driven gear is rotationally fixed to the first shaft;
• the driven gear is in rotational engagement with the forward drive gear so that the first shaft is coupled to the countershaft;
• when rotating, the driveshaft rotates in a same direction as the countershaft;
• and
• the configurable portions of the countershaft and the second shaft are free of gears;
• and
• in the second configuration:
• the forward drive gear is in selective free-spin engagement with the countershaft;
• the snowmobile further comprises:
• a reverse drive gear mounted to the countershaft at the configurable portion of the countershaft, the reverse drive gear being in driving engagement with the countershaft;
• and
• an actuator for selectively transmitting rotary motion from the countershaft to the gearbox via a selected one of the forward drive gear and the reverse drive gear;
• the gearbox further comprises a reverse driven gear mounted to the second shaft at the configurable portion of the second shaft, enclosed within the housing of the gearbox, and configured to mesh with the reverse drive gear;
• when the selected one of the forward drive gear and the reverse drive gear is the forward drive gear:
• when rotating, the driveshaft rotates in the same direction as the countershaft;
• and
• the gearbox is operable in one of the high gear, the low gear and the neutral gear;
• and
• when the selected one of the forward drive gear and the reverse drive gear is the reverse drive gear:
• when rotating, the driveshaft rotates in a reverse direction opposite to a direction of rotation of the countershaft.