Can someone point me in the right direction on locating TM shaft protective transducer cable cover?  I believe it snaps on over the cable and TM shaft  

I can't seem to find much other than there were some made for Nitro. Your best bet is to call nitro dealer to see if they know more, or contact @Wayne P. on here as it seems in a previous post he sent someone a PM about them. 

Its been mentioned that shower rod cover works too.

Do not get that. It has cut the transducer cable on several installs.

Use electrical tape or plastic cable ties ( but put the lock where the cable is so you cannot crush the cable when tightening it).

 

Thanks for the help guys.  I will use electrical tap and zip ties.   

This is what you are looking for.  I've had them on my boat for four years with no problem.  But, I did put several wraps of electrical tape on the cable at each end of the plastic shields.  I also eased the ends of the tube for the trolling motor cable by sanding a radius on all the ends.  The electrical tape was wrapped to a thickness that made a snug fit when the shields were snapped into place.  If the cable is loose, and can "rattle" around, the sharp edge if not rounded off, will cut the cable over time.