Hydraulic steering on OB drifting one way

[simonfraser]

Seems like it is slipping, but only one way
steers ok but wheel not returning to neutral when straight ahead
i‘ve had it off the grooved pin and reset it several times

running low on oil, odd, or is the hub failing ?

tnx

 

[PCUK]

Hydraulic steering always slips, there is no way to keep the wheel centred constantly. The slipping is due to prop walk. I assume there are no non return valves on the system. Fitting them will stop the side slip.

 

[simonfraser]

ah, great, tnx !

non return valves would just add more bits to go wrong, shall keep it alone

 

[PCUK]

OK.

 

[Keith-i]

As stated, depending on size of engine there’ll be some prop walk or torque steer effect. My DF200 does this on my rib and you are constantly making small corrections on long trips.

 

[simonfraser]

sure, prop walk i figured

but hydraulic slip is different ? if i make large course corrections the helm and the OB get out of synch

 

[westernman]

May be the the seal on one side of the hydraulic ram is weeping?
If you are running low on oil it is definitely leaking somewhere. Probably one of the seals on the ram.

 

[simonfraser]

May be the the seal on one side of the hydraulic ram is weeping?
If you are running low on oil it is definitely leaking somewhere. Probably one of the seals on the ram.

Yeh possible, nothing obvious, rams in plain sight

going to top it up and check fluid loss
but, should the helm go out of sync with the motor position, can go out of sync by a good 90’ after a turn during a straight run

 

[PCUK]

sure, prop walk i figured

but hydraulic slip is different ? if i make large course corrections the helm and the OB get out of synch

Absolutely right that is how it works.

 

[penfold]

Has it always done this? If it's a new phenomenon then it may be a seal failure, either in the ram or the helm pump.

 

[westernman]

Yeh possible, nothing obvious, rams in plain sight

going to top it up and check fluid loss
but, should the helm go out of sync with the motor position, can go out of sync by a good 90’ after a turn during a straight run

Something definitely wrong.

Just check you don't have a valve to disable the hydraulic system altogether. May be that is partially open. I have one on my boat. Then when turning the wheel absolutely nothing happens. This is to allow an emergency tiller to be used. However, in this case no hydraulic oil is lost.

I also use this short circuit valve it to stop the waves when moored from trying to move the rudder continuously against hydraulic pressure.

I never managed to completely stop the seals from leaking at least a little bit - even after a complete rebuild of the ram with new seals.

 

[Rappey]

but wheel not returning to neutral when straight ahead

Did it use to self centre? Is it powered or mechanical? What is the max hp of your steering system and hp of the engine?
Do you have an autopilot?
I would think the non return system is built in to most helms, without it the outboard would always be fighting you due to prop walk which surely would defeat the object of hydraulic steering?
If your turn the helm but the engine doesnt quite feel like its turning, thats usually low fluid/ air in system.


.

 

[PaulRainbow]

Yeh possible, nothing obvious, rams in plain sight

going to top it up and check fluid loss
but, should the helm go out of sync with the motor position, can go out of sync by a good 90’ after a turn during a straight run

A little creep is not uncommon (depending on the system) but 90 deg sounds too much.

 

[PCUK]

Did it use to self centre? Is it powered or mechanical? What is the max hp of your steering system and hp of the engine?
Do you have an autopilot?
I would think the non return system is built in to most helms, without it the outboard would always be fighting you due to prop walk which surely would defeat the object of hydraulic steering?
If your turn the helm but the engine doesnt quite feel like its turning, thats usually low fluid/ air in system.


.

Some systems don't have nr valves to allow for “feel” in the wheel when steering so still quite likely the problem.

 

[PCUK]

A little creep is not uncommon (depending on the system) but 90 deg sounds too much.

I'm sure he's not that bad!

 

[QBhoy]

That’s not normal at all, I’d say. Must have low oil, need refilled or bled. All three possibly. Not sure about the “returning to neutral” thing though. It won’t straighten the wheel itself from a turn, like a car will. If that was assumed. Perhaps it wasn’t. Thought I’d mention anyway

 

[simonfraser]

That’s not normal at all, I’d say. Must have low oil, need refilled or bled. All three possibly. Not sure about the “returning to neutral” thing though. It won’t straighten the wheel itself from a turn, like a car will. If that was assumed. Perhaps it wasn’t. Thought I’d mention anyway

did not suggest an automatic return to straight ahead like a car, perhaps if i had twin OB's with a bit of toe in or out

OB getting out of sync with the wheel steering, will be topping it up first of all