A piston support housing for a transmission assembly includes a plurality of axially-extending finger portions engaging a plurality of spline portions formed in a corresponding transmission case, and a plurality of friction plates are assembled adjacent the piston support housing such that the finger portions extend circumjacent peripheral edges of the friction plates. The friction plates include a plurality of torque-transmitting spline portions disposed circumferentially intermediate the finger portions. The friction plates also include a plurality of recesses disposed with one adjacent each of the finger portions to preclude contact between the finger portions and the friction plates thereby preventing torque-transmission through the finger portions to the transmission case.