Steering System Maintenance

Here we step through the steering system on the Nordhavn 52, showing some of the wear points and the changes we have made to minimize these issues.

Finally, we show the removal and replacement of the hydraulic steering rod end. This is the part that transfers force between the hydraulic cylinder and the steering arm. We show how to change it since they typically only last 1,500 to 2,500 hours in heavy use.

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26 comments on “Steering System Maintenance
  1. Brian Johnson says:

    I really enjoyed your video, it prompted me to check my older 47 steering although i did not have a pile of shavings it was quite loose. I discovered that Pae or the p/o’s used a 5/8 heim with no ptfe in the ball. They also used a 5/8 bolt going through the 3/4 inch hole in the stainless arm with a bushing to make up the difference, well sort of , there was about a total of 60 thousands of slop between the two. I made a new bushing and put a quality FK heim on the ram. although its still a single shear system I feel confident its better then it was.
    Thanks again for your informative videos.

    • It’s good you got on that problem. The loads on that part are impressively high so I would recommend properly sized parts, a grade 8 nut and bolt, and properly torqued. There should be no movement between the bolt and the rod end. We’re glad you investigated your configuration and were able to make changes before seeing a problem.

  2. Per-Ola Selander says:

    As always, amazing video and narrative! Thank you.
    Others have already commented on points I’d have raised as well, but I am curious as to the design of the steering arm and the attachment to the ram.
    Now the forces are enormous and “only” supported by the proper torque on that bolt. As long as bolt is tight, no issues
    (assuming rod-end bearing not worn). I wonder if it would have made sense by Nordhavn to put a “fork” at the end of the steering arm, as then the forces would not have been trying to “tilt” that bolt but instead been distributed by a point above AND below the rod-end bearing.

    And very interesting (rather scary….) to see what happened in the mid-Atlantic. Will dig through your site to see if I can find more details on how on earth you managed to replace that bolt in such seas…
    Which leads me to a speculation; bolt was now badly shaven and had lost a fair amount of material; would heavy lubrication of friction areas been able to at least allow to avoid the replacement while out at sea?

    And, unless you already know it, I can tell you that Seattle is currently under a deluge of water (50F and it is coming down at a rate of about .2 inches and hour at the moment), so I can’t wish you a Merry Christmas from a winter wonderland this year (although not that different from normal winter weather in Amsterdam).

    • Your right that the asymetric loads are high on the bolt and a yoke design would lower the diagonal loadings. But, in my opinion, the current design if properly torqued will work fine and is more than strong enough. However, as can be seen from the picture, it does fail badly and quickly if not properly torqued. My take is it’s easy to have it torqued correctly and, as long as this is done, it’ll hold the loads fine.

      Your right on it being an adventure to change that bolt in heavy seas. I wish I had video of it — it probably would have been at least a bit amusing. Jennifer had a very large wrench to hold the rudder. I removed the pin and planned to drop in the new one while Jennifer held the rudder firmly in place. She successfully held the rudder but the there was so much force on the rudder than Jennifer’s entire body ended up swinging. With both of us holding the wrench, we could stabilize it fairly well but then there were no arms left to change the bolt. We ended up holding it until we had it timed well between two smaller waves and then I released the rudder and Jennifer held it while I changed the bolt.

      One of the problems is the rod end bearing is below the wearing bolt so the rod end is taking metal debris and, as a consequence, it’s wearing badly as well. But we had a spare rod end so that was a solvable problem.

      You asked if we could have left it in place and used lubrication to hold it. I’m not sure but suspect if we got to it early enough it might have worked. But, with even a few hours of wear in rough seas, there was already enough wear that it was moving fairly badly and I was worried about it fracturing. We might have been able to baby it in using heavy grease but it would have been a last resort only if we had no candidate replacement bolts. There is a good chance that heavy grease could have gotten it to last the week or so we needed.

      I hope the Seattle weather improves for the holidays.

      • Per-Ola Selander says:

        Thanks for the long explanation. You failed to tell how terrified you likely were, having both of you crouching and working in a tight lazarette, in rough weather in the middle of the North Atlantic, no one on the bridge, and with no real “ocular” capabilities up top (would not surprise me if you pulled down a monitor in order to “see” out, but of course will never be the same as a pair of eyes).
        Weather will get better tomorrow (Sunday).
        Merry Christmas!

        • We have an alarm that will trigger every 10 min if nobody is on the bridge to touch the switch. The system is primarily there to ensure nobody inadvertently falls asleep but it’s even more useful to ensure that the helm operator doesn’t get engaged in reading, doing some task, or some other distraction. It’s always on when we are off shore and it’s a good reminder for us to keep checking around the boat every 10 min even when we are working on mechanical systems or doing some tasks that requires both of us.

  3. Alec Peterson says:

    This video was really instructive, but I’m most interested in how you addressed not having the bolt shear off as it was wearing down during your trans-Atlantic crossing. How did you do that with the boat underway and in stormy seas?

    • We had a spare bolt on board and were able to replace it before it failed. As long as the bolt is torqued sufficiently, there will be no flex or motion and there should be no wear under normal operation. But we do have a couple of spares on board. Replacing the bolt is normally fairly easy but in rough seas there is considerable rudder load and movement so it did require some care and patience to make the change.

  4. Ed Fisher says:

    As an aerospace design engineer I was disappointed in the original bolt/nut design. For something where torque is of any concern to the joint we would never use a nut with a hole in for exactly the reason you state: you cannot get the torque right.

    The reason the spherical bearing is failing is not because of improper torque, in my opinion. It’s because the teflon lining is wearing out from all the dynamic loading in a seaway. Essentially, the bearing is undersized. Get one that has a metal bearing with a grease fitting. It will have triple the capacity for the same size.

    • Yes, I think you are right. These designs evolve and I could imagine how that one came to be. If the nut comes off, it’s a potentially catastrophic problem. There are lots of good solutions to that problem but drilling a hole through the nut and installing a cotter pin is unquestionably effective. I suspect the down-the-road service and the potential for wear and parts size variability wasn’t given sufficient thought. I’m guilty myself of not thinking the issue through. I agree with you that the cotter pin, although initially effective, isn’t an acceptable solution and the Aerospace segment is full of mission critical good solutions that stay safe over time. Thanks for passing on your thoughts.

  5. Howard says:

    Loving these videos. Even without a boat! Hopefully, someday I’ll have a Nordhavn and can put the learning to use. Inching closer to zero brokerage boats available in size range I’ve been interested in.

    • Thanks for the feedback. Good luck in getting things lined up to get a boat yourself. For sure, getting a boat has given us some amazing experiences but they will also leave a noticeable gap in the pocket book. Totally worth it but, to make a boat worth purchasing, you have to use it frequently.

  6. Erik Reid says:

    As a helicopter mechanic its always interesting to see how other people do maintenance in different fields. Little tips and tricks are surprisingly universal. (The two adjustable wrenches was definitely cringe worthy in a normal setting lol, but completely acceptable given your lack of space on a boat). Looking up a general torque spec for a given type of hardware is not something you see many people do. Usually the German torque of “Gooddentight” is used. Nice to see you go the extra mile. I do have a question. The plate below the rod end bolt. If it is not structural, have you considered drilling an access hole in it to allow you to get a socket on the nuts from underneath? That and a deep socket would make removing and reinstalling the nuts much easier.

    • Jacques Vuye says:

      Speaking of which: Is there any reason not to mount this bolt with its head down , and the nuts on top.
      There would be no problem then to use the socket and torque wrench on both the nut, and the lock nut ?
      Am I missing something?

      • No, nothing at all wrong with doing that and I considered it but I don’t find it aesthetically pleasing and it catches on my clothing when I’m reaching over it. So, your suggestion is probably the easiest to execute upon and would be structurally identical but non-technical issues led me away from that approach. Nice solution.

        • Jacques Vuye says:

          So what (wrench) size are these nuts?
          I think i may have an idea to cap them… ;)

          • The wrench size is 1 1/8″. I’m going to declare this job complete at this point and switch my focus to getting spare parts. I’ve got a request into FK Bearings to see if they would be willing to do a 3/4″ rod end with a 7/8″ threaded hole. Failing that, I’ve found a source of the original steering manufacturer (Sea Star Solutions) part which I think is just a standard 3/4″ rod end that has been done as a custom manufacturer run with a 7/8″ hole. Since I can get the Sea Star Solutions part for about 2x what a standard part costs, I may just head down that path for expediency.

    • That’s a really nice and simple solution that I definitely should have thought of earlier. Technically, it is a structural component but a hole large enough for a 1/2″ extension wouldn’t have a negative impact upon it. But given the frequency I need to change the part isn’t that high (1,500 to 2,500 hours) and the hassle of drilling a 3/4″ hole through 1/4″ plate stainless steel, I might just stick with the current approach even though yours is much more elegant. Thanks for the suggestion.

    • Chris Barber says:

      I was going to say the same thing about the hole in the plate the instant I saw the configuration! I would even go so far as to design a fitting that would hold a socket on a jackscrew through that hole so that you’d drop the socket through the hole onto the jackscrew, line the rod end up on the hole, and jack the socket up onto the bottom fastener so that it would hold it for you while you tighten the bolt from the top with the torque wrench. I’m a convenience overachiever, I know!!

      • I think I’m going to declare this job done and just focus on getting a few spares of that rod end. I have a request to FK bearings for a custom part which I think they probably won’t want to do. I may just buy 3x of the OEM parts which look like a custom production run on standard 3/4″ rod ends.

  7. Jacques Vuye says:

    As always, interesting to see how you take care of “mission critical” components. I’ll have to take a close look in my Machinery’s Hanbook to see wether your idea of boring out and re-threading theso called “sprint car” component to the larger size.
    Will keep you posted

    • Hey Jacques! Given the manufacturer supplied part has exactly the same outside dimensions as the 3/4-16TPI part, I’m thinking it’s highly likely that there manufacturing process is to either take a 3/4-16TPI part and re-cutting it to 7/8-14TPI or to just pay the manufacture to do a special run with larger bore and thread size. Given this part lasts 1,500 to 2,500 hours, it may not be worth the hassle to change but I’m always interested in what it would take to do it better.

  8. Eric Meslow says:

    Wrong video! Watched that one last week! :)

  9. Trond Saetre says:

    Nice to see some technical DIY videos.
    A great way to learn.

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