Saturday, March 16, 2013

Shifting: A New Morse MT-3 and New Cables


The sour note of our last sailing trip is that the starboard side of the MT-3 engine control and the port shift cable both packed-in on the way back. This left us trying to back into the slip with one person shifting manually and the other driving. Because we were far to timid with the throttle with this handicap we failed and pulled the boat in with lines instead, which is really quite easy, just not our normal way. But really neither failure was a surprise. The shifter had been gimpy fo ra year and I noticed a crimp in the port cable when I swapped the engines, but I was too tired to muck with it then.

I shopped around for pricing but found nothing much better than West Marine (I had a discount card handy) and I wanted to do the swap on the weekend anyhow; Jessica has an over night next week with some friends. Spring Break and all that.

The simplest way to run the cables is simply to couple the new to the old with a coupling nut--$0.57 each plus shipping from McMaster/Carr. Unfortunately, UPS didn't make it in time, so I had to go into the shop, play machinist, and make my own. Not difficult, with a bit of 1/2-inch brass rod, drill press and table vise, drill bit and #10-32 tap. Brass is a pleasure to machine, so only about 10 minutes. Thinner stock would have been better, but it is what I had.

The tools and parts:
  • MT-3 controller. The starboard side unit had some problems, but the port side is still fine. Lots of good parts. Upon closer examination, the PO had changed the starboard cables and I think the controller damage was done during that effort. I believe they did not remove the fiberglass mount and that this caused them to force the connection (not enough room to work).
  • 2 x 8-foot Teleflex Ultra 10-30 universal type 3300 cables. One was failed (cover split and rusting at the engine end), the other makes a good spare.
  • 2 x 11-foot Teleflex Ultra 10-30 universal type 3300 cables. One was failed (swivle broken loose at the engine end and buckling), the other makes a good spare.
  • Coupling nut. Possible without, but perhaps more difficult. 
  • Waterproof grease. Never hurts.
  • A few screwdrivers, scraper, needle nose pliers (for cotter pins and c-clips) and Vise-Grip needle nose grip pliers (for engine spring clips). Not very tool-intensive.
I'm thinking the increased flexibility of these upgrade cables may reduce the stresses placed on the cables when the engines are raised; time will tell.

    The procedure:

    • Release the cables from the engine connections (pull spring clips), remove the plastic end fittings and lock nuts, and pull out of the engines.
    • Unbolt the MT-3 control from the fiberglass mount, cut the caulking loose and break it free, but do not it pull out.
    • Remove the screws that hold the fiberglass mount to the bulkhead, cut the caulking and break loose.
    • Thread 5 feet of rope through the fiberglass mount and suspend it up about 1/2 way. Easier to work with at this height and less cable friction when pulling. Place a towel behind the mount as you slide it down to prevent scratching the bulkhead.
    •  Pull the MT-3 control up and remove the 2 screws that hold the halves together (just below the mounting flange, fore and aft). Separate.
    • Remove and tag the neutral switch wires.
    • Remove the end fittings from the control end of the cables.
    • Pull the old MT-3 control out, one half at a time.
    • Thread the new cables to the old cables using the coupling nut and pull. work slowly, pushing and wiggling and NEVER forcing. For starboard, stay well to starboard  when going up the bulkhead; the gap is wider and the run easy. For port it helps to reach in front of the battery box and help the cable make the turn. Also, push the cable across under the door more than pulling, keeping it LOW down near where the wires run; if you let it pull up high it will jam. Once across to starboard and visible in the engine well, pull up while feeding across.
    • Set the new MT-3 to either pull-throttle or push-throttle, whichever you have. Look at the old control and consult the MT-3 manual. Easy.
    • Connect the neutral switch wires.
    • Connect the control cable ends. Connect the engine ends, and adjust. This is simple if the handles are in neutral and the throttle at idle. Get everything tight, as vibration will work them loose (when the PO replaced the cables he did not get one hard-to-reach screw tight and it came loose).
    I suspect this could be done without removing the fiberglass control mount; the cables would pull fairly far under the battery shelf but you should be able to reach them. I did it this way because I had read a post that showed it this way. I think this way is probably easier.



      All of this took about 1 1/2 hours including a lunch break, with the help of my lovely daughter. A one person job? Sure, it could be. In fact the easy button was working quite well and the job was not nearly the epic I feared. However, it's certainly worth replacing the lot all at once, though, onafter the controller is out.

      Silky smooth, and very shiny!

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