H54 Rudder Extension Failure

[elecco]

Am preparing to make a passage from Puerto Vallarta MX to San Francisco.  While inspecting my steering and rudder systems (H54 / 11) I found a crack on the emergency tiller extension right where the retaining pin is at the top of the rudder post.  I removed the deck cover and was able to pull the extension out with the retaining pin in.  The crack goes around the entire circumference of the extension where the retaining pin is.  The lower end of the extension is still in place. 

Has anyone else experienced this?  I want to remove the bottom part of the emergency extension but not sure what needs to be done.  It's above the waterline.  Can this be done in the slip?  Once removed I will get a new one fabricated.  Thanks in advance for any assistance.

Ed Lecco
S/v Voyager