magnetman

Yes. Hydraulics are a bit of a nuisance as you can't have a king spoke in the wheel. The bloke who built my wheel-steered trawler style boat got around this by having a duplex chain from back of steering wheel to drive to a sprocket on a 1 inch steel bar which travels to the stern via a universal joint then transfers movement via "something clever" to the rudders. I expect it is a gearbox of some sort but have not actually seen it. This means there is no creep or backlash it is a solid link and you can tell where the rudders are from the position of the wheel. There is a rudder indicator as well but it running straight off the back of the wheel. Prior to that I have had two boats with hydraulic steering including one identical to the steering in the OP photo. No rudder indicators in those boats but you can get centre by knowing how many turns it is "lock to lock", wind it over one way till it stops then wind it half way back. This is a good way to check that the rudder is unobstructed and everything is working properly. Every time you start moving do a full spin of the wheel and back to the middle.

Without this cable and the sliding indicator which is the round slotted bolt head sliding up and down the cutout on the left of the header tank you wouldn't know if the gear change had actually worked If the hydraulics were faulty the wheel would still turn but you would not know what was happening. Well you might do on a small boat as you could feel it but on a big fishing boat engine a long way away from helm it would not be obvious. The OP needs to take the screwed cap off the top and make sure there is hydraulic fluid in the tank.

Maybe boat engines are generally less active than vehicle engines so more regular oil changes help look after the problem of the engine never being run at all. Marina boats innit. Christ that doesn't read well does it ! But anyway less use should really mean more regular oil changes for obvious reasons.

Amazon is the porn of the devil so any oil from there will knock out the big ends in no time. Bloody fireworks.

It might be a facet pump with dodgy mountings. One of these ones I had one on a generator once and it was a bit noisy. The ticking is not necessarily to do with the speed of the actual pump. It seemed to come and go but was related to a bad rubber mount between the pump and the generator body.