Rudder sending unit adjustment

[Helmsman]

Any ideas on how to loosen, adjust, and re-tighten this rudder sending unit? I am off on the gauge by about 5%. It is tough to get back in there and just wanted to “go in once”if I can. It looks like the metal rod has threads, at least on the end connected to the sending unit, but wasn’t able to get close enough to tell for sure. Also don’t want to break it.

[Midnightsun]

There are threads on each end of the shaft with a locknut. they are left and right hand thread so you simply loosen the locknut on each end, spin the connecting shaft until your desired position is achieved and lock the nuts up once more. You will need someone up top looking at the gauge to assist you while you are adjusting.

[Viper]

I agree with Hans. I will add that before you start, ensure that the rudders are centered so that you're using the center mark of the gauge to adjust to. You should also ensure that you have good clean tight connections at both the sender and gauge or the readings will change again. Most of these units are oil filled so if you see any oil around the base, I recommend replacing the unit.

Your unit doesn't use a reference voltage, and because voltages will vary and typical usage is with the engines running, you should also confirm that the reading stays the same while the engines are operating. After you've made your adjustment, run the engines to confirm nothing changes. It may change slightly but a big change indicates an electrical issue or low battery and your alternator is now outputting at a high level, so ensure your batteries are fully charged before making the adjustment.

[Lyndon670]

I have never used one of these that is acutally "accurate". I would say that you are not going to get anything more than your 5% that you say that you are off. In fact, having seen people try to play with these, they can't get the original 5% back and end up being off more.

[denpooch]

I had made the same adjustments this past summer.
If you have an auto pilot on your boat there is something to keep in mind.
When making the adjustment on my rudder sending units, we inadvertently dislodged the autopilot sensor which completely 'threw off' the auto pilot function. I would be following a heading and as soon as I engaged the autopilot to maintain the course, she would start going in circles. As you can imagine, it was very disconcerting.
After weeks of phone calls, stressful thoughts of having to replace a faulty computer, etc., we figured out the culprit.
We reattached the piece and recalibrated according to instructions and 'carried on' with life.
Certainly not a big deal but something that should be kept on mind.

[Midnightsun]

Source of the post I had made the same adjustments this past summer.
If you have an auto pilot on your boat there is something to keep in mind.
When making the adjustment on my rudder sending units, we inadvertently dislodged the autopilot sensor which completely 'threw off' the auto pilot function. I would be following a heading and as soon as I engaged the autopilot to maintain the course, she would start going in circles. As you can imagine, it was very disconcerting.
After weeks of phone calls, stressful thoughts of having to replace a faulty computer, etc., we figured out the culprit.
We reattached the piece and recalibrated according to instructions and 'carried on' with life.
Certainly not a big deal but something that should be kept on mind.

You must have a different setup compared to mine as the autopilot is on the port side which has it's own dedicated unit with the markings RayMarine on it. In other words I have 2 rudder indicator setups, one for the Auto pilot and one for the rudder indicator gauge.

[denpooch]

Simrad autopilot to starboard.

[Helmsman]

I will try to answer the comments in one reply. The sensor is off 1/6 of the 30 degrees to the starboard side. I said 5% and should have said 5 degrees. So it is material enough to correct. There is no oil leakage and no change in the rudder alignment gauge underway or at rest. It is just off. The batteries should be good since i have had them on shore power for a week. Good to know, though.

The AP sender is on the Port side of the boat so it won’t factor in. i will need to look for the locknuts. I can see one in a couple of the pictures I took.

Thanks for the help! Will report back after I climb in there. if I can get back out!

[bud37]

HeHe...good luck, maybe a little axle grease just in case.....

[daveS]

On my 350 Mariner. My rudder indicator on the dash is not working...any suggestions?