Quieting a Noisy Autopilot

[SV Demeter]

I use a Raymarine autopilot with a hydraulic Type 2 linerdrive attached to the quadrant. On the Chesapeake and in calm conditions its pretty quiet and when motoring the engine drowns it out, but offshore it can get quite noisy as it works more in the swells. The unit pump and drive are in the aft cabin and Im thinking of a way to quiet the unit. I thought of going to a wind vane self steering for ofshore work but thats an expensive solution and Im not sure how it would work with my davits and swim ladder. I was thinking of trying to enclose the hydraulic pump in SoundDown as I have some 1 1/2" material left over form another project. Im wondering though if the source of the noise is the pump or the hydraulic drive or both? Have any others found ways to quiet their pilots?

[DeepFrz]

Make sure that everything is mounted tightly and that the panels the pump and actuator are mounted on are sturdy. Its possible that one of the panels could be "oil canning" if it only happens when it is working hard.

I would start by removing all the pump mounting bolts and checking that the holes haven't worn. You might think about mounting the pump on a panel and then shock mounting the panel to the original mounting point.

Its a possibility that the hoses are moving and causing the noise. Hard to say because I haven't heard what it sounds like.

Check that there is no movement in the quadrant on the rudder shaft.

The actuator needs a very strong mounting shelf/bulkhead. Any slack in the mounting holes/bolts may cause noise when the working gets hard.

Trying to absorb or block the noise may work, but eliminating it will give you the best results. You may have to resort to both methods.

Good luck.

[Nauticatarcher]

Autopilot pump used to drive me crazy when trying to sleep in Aft cabin, just bought some longer hoses and shifted pump, no more noise

[SV Demeter]

Yeah theres nothing wrong with the equipment its just noisey at sea. Ive been on severalother boats with the same noise. I have not looked closely enough at it to determine if its the pump or the drive or both but I suspect its the pump. Nauticatarcher how far away did you move it? I was thinking of trying to enclose the pump in 1.5" thick Sounddown.

[Nauticatarcher]

Moved it from under bunk next to Ram to Aft engine room bulkhead, no problems no loss in performance No more noise

[SV Demeter]

I like the sounds of this idea a lot. Is there any bleeding process required when you relocate and add longer lines? I'm talking about a Raymarine Type 2 linear hydraulic unit.