Piston stroke controller in a torque transmitting assembly

A piston stroke adjuster in a torque transmitting assembly comprising:

• a plurality of first torque transmitting plates drivingly connected with a housing;
• a plurality of second torque transmitting plates interspersed with said first torque transmitting plates drivingly connected with a hub;
• a piston slidably disposed in said housing for axial movement in an engaging direction to enforce frictional engagement between said first and second torque transmitting plates and in a disengaging direction to permit a free-running clearance to be established between said first and second torque transmitting plates to provide a selective torque transmitting relation between said housing and said hub;
• a return spring retainer assembly having a retainer plate, a plurality of springs mounted in compression between said retainer plate and said piston, means for positioning said retainer plate in said housing, and a reaction gear profile having and plurality of teeth formed in said retainer plate;
• a helical gear rotatably mounted on one-way torque transmitting means on a post secured to said piston, said gear extending through and engaging said gear profile, said helical gear having a plurality of teeth;
• means for positioning said gear on said post;
• and
• a clearance space substantially equal to said free-running clearance adjacent said gear to permit limited axial movement of said piston relative to said retainer plate during axial movement of said piston in both said engaging and disengaging directions, said one-way torque transmitting means permitting rotation of said helical gear relative to said retainer plate during engaging motion of said piston after said clearance space is closed and preventing rotation of said helical gear relative to said retainer plate during disengaging movement of said piston after said clearance space has opened.