Rod steering lock problem

  • Thread starter Thread starter tpb
  • Start date Start date

tpb

New Member
Joined
30 Aug 2012
Messages
18
Visit site
I have Whitlock mamba rod steering and the rudder moves more to starboard than to port. Any thoughts would be appreciated.
 
I have Whitlock mamba rod steering and the rudder moves more to starboard than to port. Any thoughts would be appreciated.

I don't know anything about your steering system but i did some googling (Sorry Paul Rainbow:disgust:) and it seem s both the Cobra and Mamba are rod type steering. Here is a manual for the Cobra which may give you some clues:

http://www.eddievan.com/documents/whitlock_cobra_steering.pdf

Here is a Cruiser Forum thread which cover the Cobra as well as the Mamba:

http://www.cruisersforum.com/forums/f47/lewmar-whitlock-steering-problem-41068.html
 
Assuming you haven't always had this problem, I suspect that either the quadrant on the rudder stock isn't correctly set in relation to the rudder (should be tight and set at about ninety degrees to the rudder blade - well, it is on my boat) or the rod length has been adjusted while the rudder wasn't in the straight-ahead position.

To correct the position of the quadrant depends on the nature of the fitting. On my boat it simply clamps onto the rudder stock, so repositioning it merely requires loosening it, setting and holding both the wheel and the rudder in their correct straight-ahead positions and then tightening up the clamp again. Check the lock - if it is still unequal then the rod length needs adjusting.

I think you'll find the effective length of the rod is adjusted by screwing the position of the rod-end joints in or out as appropriate - loosen the rod-end lock nuts, disconnect the rod at one end (whichever is easiest to get to), set and hold the rudder at straight ahead, set and hold the wheel at straight-ahead (half way between the lock-stops that'll be fitted somewhere) then adjust the length of the rod so that it fits back on to the mounting pins without moving either rudder or wheel. Retighten everything. (Note: when adjusting the rod-ends make sure that after adjustment the rod-end's male thread still has two or three complete turns in the rod's female thread - too few turns might lead to failure.) If when you check the lock it still isn't right you should look again at the quadrant position on the rudder stock. And if that looks alright then . . . . well, I'd be stumped!
 
Last edited:
I think the rudder stock arm should be angled forward when the rudder is midships.
It works using wide angle geometry .
Both arms are normally angled forward so you need to check the steering arm at the binnacle is the same angle as the rudder stock .
Could be the drag link is adjusted to long.
 
I think the rudder stock arm should be angled forward when the rudder is midships.
It works using wide angle geometry .
Both arms are normally angled forward so you need to check the steering arm at the binnacle is the same angle as the rudder stock .
Could be the drag link is adjusted to long.
 
Thanks for that. The strange thing is that the rudder stock arm is in the horizontal plane and the drag link is attached to the back of the drive in the vertical plane. I believe that the steering drive is a Whitlock Mamba.
 
Could be different on a mamba system mine is a Cobra.But I think the angle issue still applies.
 
Last edited:
I have the same problem with my Cobra steering. I am fairly certain it is a result of the rudder stops being incorrectly placed. I will try to take a photo later to show what I mean.
Sorry, I tried to attach a photo but failed. Perhaps look at your system and see what is physically stopping the rudder stock being turned more on stbd and port lock?
 
Last edited:
I have the same problem with my Cobra steering. I am fairly certain it is a result of the rudder stops being incorrectly placed. I will try to take a photo later to show what I mean.
Sorry, I tried to attach a photo but failed. Perhaps look at your system and see what is physically stopping the rudder stock being turned more on stbd and port lock?

I shall certainly have another look, Thank you.
 
Many thanks to you all for your many suggestions. I have now managed to have a good look at the steering system from the port cockpit locker in the semi-foetal position.
The reason for the asymetric movement of the rudder appears to be due to the fact that the drag link is a raked drag link as a result of the mamba drive being in the horizontal plane. This installation was no doubt due to the installation of the large Mamba autohelm drive and the confined area beneath the cockpit sole.
This means that the drag link is angled upwards when steering to port and then is stopped by contact with the tiller arm slightly earlier in its travel than one would wish. I have come to the conclusion that there was no other means of installation and I am satisfied that I can live with it. The boat has a long keel and having a right-handed prop I have become accustomed to giving five burst of throttle when turning aft to port.
 
Top