Problems with a Whitlock rod steering system

[CalicoJack]

On Sunday our wheel steering from a centre cockpit locked up. There was little warning, the system went stiff and within a quarter of a turn of the wheel was locked solid. I managed to disconnect the rod from the top of the rudder; not an easy task, as I don't think that it had ever been done since the boat was built in 1979, and rig the emergency steering.

There seems to be a tiny amount of movement from the wheel down to a "steering box" where the vertical motion,on the input side, is converted to a horizontal motion, on the output side. There appears to be no movement at all on the output side.

Has anyone come across this problem before. All advice, gratefully received.

 

[PaulR]

we have whitlock cobra rod steering and last winter had it serviced by winch servicing of emsworth - very helpful chap, very knowledgeable and price fine - no hesitation in recommending him - suggest you might give him a call

 

[CalicoJack]

Thanks for the information. Calico Jack aka Nigel

 

[gfbalduc]

There are not many moving parts in the Whitlock Cobra system:
- the weel on an horizontal axle, transferring motion via a pinion to:
- a vertical rod, with a sector at the top and an arm at the bottom, and
- the connecting rod between the extremity of the lower arm and the rudder sector

The connecting rod is a likely culpright: it is connected on both ends with a spherical joint which, at least on my system, gets very rusty and may become very stiff: if you detached it on the rudder side, you may try and move it to check if it is stuck at the other end.
If cleaning/greasing is not enough, these rods ("draglink" in Lewmar terminology) are available as spare parts.

The only other potential problem points are:
- the bearings of the vertical rod
- the sector and pinion coupling between the wheel and the vertical rod, which is just under the compass: remove it and have a look, and put plenty of grease.

 

[TigaWave]

Mine had shim adjustment to allow the bevel gears on the wheel to meet the gear on the horizontal cog with the right clearance. This was part of annual maintenance check. If this gap were to get too big its possible the cogs could jam, but otherwise as others have said I'd look at the ball joints. There's not much else to them really. Details of the adjustment were in the whitlock manual supplied with my boat.

 

[CalicoJack]

Any chance of a copy of the handbook. My e-mail address is nigelames1956@yahoo.co.uk

 

[MedMan]

I agree that the ball joints are the most likely culprits. Whilst looking at them, it is worth checking for wear. I replaced one of mine (the tiller end) after 12 years as there was quite a lot of free play in it and that was despite greasing it every year as part of my laying up routine. Left unchecked a worn ball joint could eventually come apart.

 

[CalicoJack]

Thanks for all the advice. I found the problem. It wasn't in the steering boxes but a bearing which was hidden under the loo in the aft cabin. This bearing acted as a support for the shaft which ran from the steering box in the engine compartment to the sterm. I guess that over time the loo had leaked and the bearing which was well hidden had never been greased. Oh the joys of buying a new (second hand) boat!