Snowmobile with improved drive train

A method of assembling a snowmobile drive train including a continuously variable transmission (CVT) having a driving pulley and a driven pulley, the driven pulley having a fixed sheave, a moveable sheave, and a biasing spring, the movable sheave including a removable outer portion;

• the method comprising the steps of:
• mounting the driving pulley to an engine crankshaft;
• inserting the movable sheave onto a first end of a transversally arranged thin-walled hollow jackshaft, the movable sheave having a first sliding surface slideably connected to an outer surface of the first end of the transversely arranged thin-walled hollow jackshaft;
• press fitting a connecting surface of the fixed sheave onto the outer surface of the first end of the transversely arranged thin-walled hollow jackshaft, the outer surface of the first end of the jackshaft having a constant diameter;
• inserting the outer portion of the moveable sheave and the biasing spring onto the first end of the transversally arranged thin-walled hollow jackshaft, the fixed sheave being disposed along the transversely arranged thin-walled hollow jackshaft between at least a portion of the outer portion and the movable sheave, the biasing spring abutting the outer portion and the fixed sheave;
• connecting the outer portion to the moveable sheave, the biasing spring biasing the moveable sheave toward the fixed sheave, the outer portion having a second sliding surface slideably connected to the outer surface of the first end of the transversely arranged thin-walled hollow jackshaft, the connecting surface being disposed along the transversely arranged thin-walled hollow jackshaft between the first sliding surface and the second sliding surface;
• connecting a second end of the transversely arranged thin-walled hollow jackshaft to an input member of a reduction drive having an input member and an output member;
• operatively connecting a drive track to the output member of the reduction drive;
• and
• operatively connecting the driving pulley to the driven pulley via a drive belt looped around the driving pulley and the driven pulley.

A snowmobile comprising:

• a frame having a forward end and a rearward end;
• a drive track assembly disposed below and supporting the rearward end of the frame;
• a front suspension connected to the forward end of the frame;
• two skis connected to the front suspension;
• and
• an engine mounted on the frame and operatively connected to the drive track via a drive train for delivering propulsive power to the drive track, the engine having a width measured transversely across the snowmobile;
• the drive train including:
• a continuously variable transmission (CVT) having a drive belt looped around a driving pulley and a driven pulley;
• a transversely arranged jackshaft having an outer surface, a first end and a second end and extending at least the width of the engine;
• and
• a reduction drive having an input member and an output member;
• the driven pulley being press-fit onto the outer surface of the first end of the jackshaft, the first end of the jackshaft being inserted into a central portion of the driven pulley and extending through the driven pulley, the driven pulley having a fixed sheave and a moveable sheave, the fixed sheave having a connecting surface press-fitted to the outer surface of the first end of the jackshaft, the movable sheave having a first sliding surface slideably connected to the outer surface of the first end of the jackshaft, the movable sheave having a removable outer portion, the fixed sheave being disposed along the jackshaft between at least a portion of the outer portion and the movable sheave, the driven pulley having a biasing spring abutting the outer portion and the fixed sheave, the biasing spring biasing the moveable sheave toward the fixed sheave, the outer portion having a second sliding surface slideably connected to the outer surface of the first end of the transversely arranged thin-walled hollow jackshaft, the connecting surface being disposed along the transversely arranged thin-walled hollow jackshaft between the first sliding surface and the second sliding surface,
• the second end of the jackshaft being connected to the input member of the reduction drive, and
• the drive track being operatively connected to the output member of the reduction drive.