Steering Pedestal, Idler, Chain, Cable (Safety)

Discussion in 'Main Morgan 38 Sailboat Forum' started by mpearson, Jul 29, 2019.

  1. mpearson

    mpearson Mark Pearson Staff Member

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    Portland, OR
    We lucked out last weekend when one of our most important systems (steering) failed while at the dock and in a very controlled setting. It very easily could have happened when we were under way.

    We were peacefully asleep in the middle of the night at our temporary home slip in Bremerton, Washington on Friday night. Suddenly there was a loud grinding noise and the boat lurched to port and into the dock like several 200+ pound men had jumped onto our deck at once. My wife screamed (quite loudly).

    I sprang from sleep in my boxers and assumed my Kung Foo defensive combat posture, ready for battle. Things (except my heartbeat) seemed to settle down. We stood there quietly for at least 10 minutes waiting in the dark for the invaders on the deck to make their next move.

    Turns out they weren't there.

    In the morning, we surmised what had happened. The tidal current runs 2+ knots forward and backward through the marina. Some very large object had hit our rudder when it was running backward and drove us into the dock. We assumed it would be a log, but the marina staff said they had never heard of a log moving through the marina. There are 2,000 pound Stellar Sea Lions, though, so maybe it was one of those with an attitude?

    Regardless of what it was, it actually pointed out a very important safety condition (aka Achilles Heel) that urgently needed some attention: Our Idler was badly corroded and basically disintegrated when the unknown thing hit our rudder.

    What's an Idler?


    Rudder System Drawing.png

    I had previously noticed the Idler plate looked corroded/weathered, but it seemed to be solid still. Turns out not really. I think we have the original Edson pedestal & steering system that Morgan installed in the factory.

    We had to take off the autopilot arm and the Radial Drive Wheel (aka Quadrant) to get the cables free so that we could remove the cable and Idler. There are 4 big aluminum bolts that attach the base of the pedestal to the Idler plate. They were fused and unmovable, although one of them was sheared off during this incident. I drilled out the other 3 and will be replacing with stainless steel. I don't really understand why they would use aluminum for those bolts.

    Located at the back of the engine compartment, the Idler is in one of the least accessible areas of the boat. A few marine-grade curse words were dropped and I'm thankful my wife is more portable and nimble than I. She did the hard parts.

    This is what the old Idler looked like. If I picked it up by one of the sheaves, the whole thing would fall apart.

    Corroded Idler.jpg

    On Monday morning, I had a very helpful conversation with a knowledgeable gentleman named Reed at Edson International. He helped me find the right replacement part (Adjustable Crossed Wire Idler, part number 776AL-4AL).

    He also highly recommended replacing the chain & cable - even if they still look good, every 10 years. Mine still looked OK, but I know it hasn't been replaced in 18 years, so we are doing that too. I guess they develop hairline cracks in the chain where you can't seem them until they fail.

    So we have those parts on the way and will be heading back up to Bremerton on Thursday to get things put back together.

    While she is taken apart, we needed to keep her rudder from flip/flopping in the tidal currents. So we put together and used our Emergency Tiller for the first time. Good practice and we were able to confirm it works. If the Idler had failed while we were out voyaging, we would have used this Emergency Tiller. It was good to learn it is not a 2 minute fix, but rather would probably take 20 minutes from start to finish to get the tiller working.

    Caveat: we have a 1983 Morgan 384. I've seen photos of some earlier M38s that used a different quadrant/steering, etc. So your part numbers may vary.

    Anyway, we are really thankful this happened when it did. We have spent considerable time and money being sure our boat is safe. It would have been ironic if this one little piece had failed at a bad time. I'll post about the progress after we get it fixed.
     
    Last edited: Jul 29, 2019
  2. terry_thatcher

    terry_thatcher Terence Thatcher

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    thanks for the report. I rebuilt the whole kit and caboodle (except the idlers) before going offshore a couple of years ago. Replaced the idler sheaves. Looks as if you had leaks onto them. Bad design to build them our of mild steel. Are the new ones still mild steel? And maybe nothing hit the rudder. Perhaps the current (if it was running from the stern) just caught the rudder and slammed it over, Was the brake on.
     
  3. mpearson

    mpearson Mark Pearson Staff Member

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    Portland, OR
    Hi Terry - I hope you're having a good summer and I want to hear more about your boat painting experience, after you get it figured out ;-)
    Yes, I think there must have been leaks from the pedestal base onto the Idler plate back when Zia was only in salt water. And yes, it was some kind of mild steel. The newer ones look quite beefy and are anodized aluminium.

    https://edsonmarine.com/adjustable-crossed-wire-idler-4-sheave/

    I'm also going to make sure there is no leaking from the pedestal.

    Yes, the current was running from the stern at about 2.5 knots. Wheel brake was on, and that might have added more stress. If the wheel brake was off, it would have been pinned over on the rudder stop (rubber pad) on the quadrant.

    Oh well, it was the one important system on Zia that I wasn't 100% sure about. Now I'll be sure ;)!

    Cheers,
    -Mark
     
  4. stnick

    stnick lee nicholas

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    Just so you Know any Motor Cycle shop has SS chain that will fit the edson steering system. It does not say EDSON for 80% more money . But works just the same.
     
  5. mpearson

    mpearson Mark Pearson Staff Member

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    Thanks Lee! I already installed the new Edson chain & cable. I didn’t even think about value shopping and wish I had!

    We installed the new Idler & Sheaves last weekend. Wow, they look so much better. See old/new photo below. The old pedestal apparently was not sealed well at the base and apparently salt water from the cockpit floor had dripped on the Idler for many years. We did a good job of sealing the pedestal base with Butyl so it won’t leak.

    E03F53E5-2654-413E-BC59-4D75B69EBB47.jpeg

    I feel good knowing we’ve replaced the Idler and now have new chain/cable.

    We also replaced the GFO rudder post packing. The rudder post nut is sure a pain in the butt. Last time I did it was fairly easy to stop all dripping. This time it was a major pain. I was looking at the photos of your wrench, but I used a chain wrench because that’s what I used last time. I just ordered a Buck Algonquin Packing Box Wrench in hopes that it makes life easier.
     
  6. terry_thatcher

    terry_thatcher Terence Thatcher

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    Mark, how complicated was it to get the angles correct on the adjustable idler? And does the whole pedestal have to come off to replace them?
     
  7. mpearson

    mpearson Mark Pearson Staff Member

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    Hi Terry - it hasn’t been too complicated, although it’s not totally done yet. I used a normal T-Bevel (shown below) to measure the angles on the old Idler and transfer to the new.

    CC215A09-C703-4F2E-858A-760B6F703088.jpeg

    Because the old Idler was so disintegrated, getting an exact angle was a little clunky. Now that it’s all mounted I used a mirror to sight down the cable from the Idler to the edge of the Radial Drive Wheel (aka quadrant). My Port sheave looks a little off, so next weekend I am going to adjust it by releasing a nut on the Idler, adjusting, and tightening again.

    Of course, this is taking place in one of the least accessible parts of the boat, but it helps improve your flexibility!

    No, the whole Pedestal doesn’t need to come off. However the 4 big bolts that hold the Pedestal down also secure the Idler to the roof in the engine compartment. So I needed to remove those, and they were fused to the base, so I had to drill them out. They were Aluminum so that was easy. I also had to clean and seal the base of the Pedestal to prevent the leaking which caused the Idler to be so corroded in the first place.

    The pedestal part was pretty easy. Below is a picture with the Pedestal removed (in the foreground), and the hole where it is mounted in the background. This was after we had cleaned the deck where it is secured, and we were getting ready to apply the Butyl & seal it.

    9E60A863-3911-48B9-BAE4-57D5C030E0BA.jpeg
     
    Last edited: Aug 6, 2019
  8. mpearson

    mpearson Mark Pearson Staff Member

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    Portland, OR
    Terry - we finished up last weekend and I can say that adjusting the sheave angles on the Idler was not easy. Mostly because of the really awkward location of the Idler. It took two of us going in at the same time: one from the quarter berth and the other laying inside the cockpit lazarette. One of us could see things but not reach them, the other could reach but not see. We could both curse. We loosened the cables and bolts, then hammered the port sheave to slide it into a perfect position.

    It took about 2 hrs, including the time to dig everything out of the lazarette & quarter berth and remove the partitions. I could kick myself for not replacing the Idler, chain and cable when we replaced the engine last fall. It would have been quite easy without the engine, transmission & exhaust being in the way. Oh well.

    We are continuing our search for a very small person (previously improperly known as a ‘midget’), who is also a contortionist and a marine mechanic. They are very hard to find but would be very helpful on our boats.

    I am very happy with how it all turned out, though. I really do think it’s “better than new” since this Idler seems to be a lot more beefy & corrosion resistant.

    32CA0FF7-A03B-4398-BED1-DA933E2A055F.jpeg

    Above is new Idler, sheaves and cable. Hanging from ceiling of engine compartment, aft of the engine.
     

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