Abstract: The top wall of a snowmobile tunnel, which accommodates the endless drive track of the snowmobile, is provided with recesses at locations corresponding to the path followed by studs carried by the endless track. The rear of the tunnel is connected to a molded rear member having a pattern of recesses matching that of the top wall of the tunnel. In yet another aspect of the invention, a heat exchanger for cooling engine coolant may be provided at the rear of the tunnel. The heat exchanger may be mounted to and partially spaced from the molded rear member. The heat exchanger may bear rearwardly extending ridges with upwardly extending lip at the far end. In some embodiments, a channel is provided on the upper end of the heat exchanger to promote air and snow flow over the rearwardly extending ridges.

Abstract: A snowmobile includes a pair of skis connected to the snowmobile frame by a forward suspension including a pair of telescopic struts which are biased to normally extended positions and are connected to a stabilizer member including a transverse torsion bar. A drive track of the snowmobile is suspended from the frame by a rear suspension, including a link pivotally connected between the frame, and a pair of slide rails and biased downwardly by a pair of torsion springs having respective ends engaged with a pivotally mounted spring end retainer which is connected to the torsion bar of the forward suspension by a pair of motion transfer links which act to "soften" the rear suspension in response to upward telescopic movement of one or the other or both of the telescopic struts.

Abstract: A snowmobile includes a pair of skis connected to the snowmobile frame by a forward suspension including a pair of telescopic struts which are biased to normally extended positions and are connected to a stabilizer member including a transverse torsion bar. A drive track of the snowmobile is suspended from the frame by a rear suspension, including a link pivotally connected between the frame, and a pair of slide rails and biased downwardly by a pair of torsion springs having respective ends engaged with a pivotally mounted spring end retainer which is connected to the torsion bar of the forward suspension by a pair of motion transfer links which act to "soften" the rear suspension in response to upward telescopic movement of one or the other or both of the telescopic struts.