Patent ID: 7069806

Claim:
A transmission comprising: a main gear box; an auxiliary gear box secured to said main gear box including an auxiliary shaft supporting at least one auxiliary gear, and a clutch collar supported on said auxiliary shaft adjacent to the at least one auxiliary gear, and selectively actuatable between engaged and disengaged auxiliary gear positions; a piston movable within a piston chamber, and controls for supplying pressurized fluid to at least one side of said piston and into said piston chamber, a bore being defined to support a shift shaft which is connected to move with said piston, said piston having a greater diameter than said shift shaft; a transmission fluid received within said auxiliary gear box; said shift shaft movable axially with said piston between first and second positions, said first and second positions corresponding to the engaged and disengaged auxiliary gear positions, said shift shaft supporting a shift fork that engages said clutch collar, said shift shaft having an annular groove; and a seal disposed in said annular groove for engaging said bore and said shift shaft, and for separating said transmission fluid from said pressurized fluid.