Dual pressure shift actuator assembly.

摘要

An auxiliary transmission section (14) shift control system (230)/method is provided which includes a control member (234) to prevent auxiliary section synchronized clutch (92, 128) damage if the main transmission section (12) is engaged during an auxiliary section shift. Upon sensing main section engagement during a shift into the auxiliary section high-speed ratio, the force used to engage the high speed ratio is reduced from a first to a considerably lower second level by reducing the pressurization of the actuating pressurized fluid. To accomplish this, a dual pressure pressure regulator assembly (234) is utilized.