Abstract: A multi-position positive clutch is disclosed for use with a between-front-and-rear axle (center) differential of a multiple drive axle vehicle. One clutch member is biased to an overrun position by a fork slideably biased on a piston shaft from a main piston which, when operated, moves to bias the one clutch member in an engaged position. An annular piston, slideable on the shaft, responds to vehicle fluid brake pressure above a predetermined minimum to disengage the clutch. Clutch teeth have a dovetail shape for camming the clutch plate into engagement whereupon switch means are operated to indicate the locked position as well as opposite rotation in the overrun position.

Abstract: A multi-position clutch is disclosed for use with a between-front-and-rear axle differential of a multiple drive axle vehicle, having an engaged position to eliminate differential action in transmitting power between front and rear axle, normal intermediate overrun clutch position to prevent front wheel spinout faster than the rear, and a completely disengaged position for elimination of overrunning clutch lockup and excessive front driveline torque loads during moderate to panic brake applications. The clutch includes a linear fluid motor responsive to front-axle braking of the vehicle for applying fluid pressure in a first direction to the fluid motor to transfer the clutch to the disengaged position at a predetermined vehicle deceleration to prevent excessive drivetrain torque buildup between the front wheels and the rear brakes.