A hollow double-acting cylinder assembly may be mounted over a shaft and to a housing. A moveable piston of the cylinder assembly connects to a sliding sleeve of an over-center mechanism and the sliding sleeve with a thrust bearing allowing it to push and pull the sleeve mechanism with cylinder action. A toggle action of the over-center mechanism locks clutch without the need to sustain pressure on the cylinder after engagement/disengagement motion. As the clutch is typically engaged for sustained periods of time, this prevents constant hydraulic pressure applied to the over-center mechanism and significantly reduces wear. Hydraulic/pneumatic hoses may pass through the housing and connect to engage and disengage bores of the cylinder via remotely actuated control valve(s).