420: Steering Bearing Failure !

[PiratePete56]

Thought the engineering on the steering system looked bulletproof on our 2007 L420 but managed to break it in pretty heavy conditions! The autopilot actually broke it, not me! Lost one rudder connection and autopilot function when it happened, and discovered steering by compass is difficult. Managed to get to our intended anchorage safely.

The bearing post on the rudder lever has sheared, on the port side where autopilot ram and position sensor is connected. Photo is of the other unbroken post that is fortunately the same, so I could swap them over. With a bit of spectra rope tying the lever to the end of the link beam we are underway, steering a bit sloppy but good enough to continue cruising to port for repairs.

My question is if this is a standard bearing fixture or something Lagoon had made? Can I buy it off the shelf, or will I have to have a new one made? A reasonable internet search has not found an answer. If its a custom part it will be reasonably easily reproduced by a competent fitter, and I can get a spare at the same time. Wont bother asking Lagoon because their prices will probably drain my super fund!

Appreciate any advice I can get. Has anybody else mananged to break one of these?

[a64pilot]

I believe that is custom, and any good machine shop can replicate.
I’d also bet lunch that the failure was because the threads were cut and not rolled.
A good shop can cut off a bolt that has rolled threads which is almost all bolts and weld it to what you have.
I’d cut off or grind the broken piece off, drill it for a bolt shank to fit into and weld it in.
It could also be drilled and tapped and a piece of all thread screwed in, but I’d rather go the bolt way myself, and would be tempted to go with grade 8.
That ought to me much, much stronger than the part was new.

[a64pilot]

Now that I look at the picture I feel certain that the part can be drilled and tapped and simply a bolt tightened into it, which is an easy fix and allows a super strong bolt like a grade 8 to be used, it’s a simple operation and the bolt is replaceable too.

[steve450]

The picture you have with the steering linkage connected is up side down the threaded part shoud be screwed from the top into the arm.the smooth top with the split pin hole goes to the top.the linkage then sits on top of the arm with a washer on top then the split pin is put into the hole to secure it.
The main cause of failure is the auto pilot pushing the arm against the stops due to incorrect calibration in the initial set up in the auto pilot set up. The other one is while reversing the steering it bangs fast and hard against the stops.also the pins require the nuts be checked for tightness with the tie rod ends being abel to pivot on tha axis as in a car tie rod end the pins are standard untill approx 2012-2013 they then are welded to the bottom of the arm i have found many of these tie rod ends seized and unable to pivot as this is often not checked regularly. It is very easy to remove the steeing arm of the rudder(no it will not fall down) the get it welded to the arm.any engineering firm can make these very easy so you can have a spare.