Hi again FCH, The extended part of the shaft, to the rear of the wheel, or possibly the front whichever way round it may have been fitted, was intended to enable a
remote or
autopilot fitting. In your
photo, it appears to enter a box panel, which may support
compass or
electronics. This assembly will have to be removed/diss assembled to gain access to the principle fixing nut as previously described. The shaft, is in fact a one piece machined item, which is keyed to both the wheel and the drive sproket, if it is link chain, or the cable control wheel. There is a
single bearing located at the business end of the support system, against the drive sproket. This is within the part of the pedestal that has the circular cover plate and many screws. Dont even try and dissassemble from that end. In the unlikely event that it is a very early type of unit, it may even have a drive shaft , leading to a right angle box and mechanical lever to the
rudder. The actual pedestal wheel, always comes away from the end further most from the final drive.. Hope this helps, as I know there is not much printed info available from Whitlock, even when they were supplied to
boat builders... h the boat.