Gear yoke Point X Steering spindle Steering cylinder “A” Pedestal Steering drum Steering emergency release switch Orifice rod Steering cylinder “B” Centering cams Metering valve Compensator Steering wheel Safety shutoff valve Differential assembly Differential arm Differential link Follow up drum Pulleys Pulleys Follow-up cables Steering cables Figure 13-51.  Example of a large aircraft hydraulic nose wheel steering system with hydraulic and mechanical units. 13-31