Snowthrower wheel drive steering system

A snowthrower has independent wheel drive trains to allow steering by clutching one drive train while unclutching the other drive train. The clutch in each drive train comprises a plurality of pivotal pawls carried on a drive member with the pawls pivoting in a plane that is substantially perpendicular to the rotational axis of the drive member. The pawls have heads that project through one face of the drive member and tails located on an opposite face of the drive member. The heads of the pawls can engage or disengage notches that are fixed to the driven member to clutch or unclutch the drive and driven members. A shift member axially presses on the tails of the pawls to disengage the heads of the pawls from the driven member. The shift member is selectively moved by an operator using a steering lever on the snowthrower.