Latham Steering Function - How can this be right?
 

I have Latham steering on a Baja 342 installed at the factory. I had the drives off last week. When I put the drives on I started the engines. With the engine running, as you steer, both drives move out. Both pistons "push" but not "pull". When the system is connected with a tie bar that is fine. But, if I ever break a gimble or the tie bar system fails, I am dead...

I have seen race boats running with the tie bar flapping in the water or even a broken drive. Was this set up wrong from the factory? I assume its a plumbing issue or is it possibly a control valve at the helm? What is wrong here?

Sorry, I was chuckling when read your post, I can imagine the look on ur face, well it doesnt sound like you pulled any of the lines off, to get them crossed, so IMO they need to push against each other to work properly.

If it was wrong the boat wouldn't steer. With it all disconnected its just the pressure evening out. If there was resistance on the rams the fluid flow would be normal and one would push while the other pulls.

OK, let me clarify. There isnt "pull". Only the push function works.

If you disconnect the tie bar and turn the wheel one drive will move - the one in the "push" position only. You turn the wheel the other way the other one moves. It seems like they only push. With the tie bar on, that is great. With the tie bar off, it is scary.

That's because the 'push' side has more PSI surface area than the pull side. (cyl rod), so the push side will move 1st. If you kept turning the wheel, as soon as the push side was extended the full amount, then the other drive would move. it's kind of a path of least resistance thing, with the area of the cyl rod creating a slight amount of resistance. In a round about way.
I'd think with the race boats running, the high rpm is what allows this equalization happen at a much faster rate. Nature of the beast with the rams tee'd together

Interesting! Very logical answer.

So, this is a tree fell in the woods scenario. If I were at 80 mph and a gimble broke would I barrel roll & die or would I be ok due to the high RPM?

Just be glad that you had the hydraulic steering on. Friend hit something under the water doing mid 70. We just added hydraulic steering earlier in the week. Ripped the starboard drive right off. Only thing holding the drive on was the steering ram and tie bar.

Yeah, but he had cable backing it up. If that happened to me, I would have taken a sharp left.

You arent understanding. If the tie bar is on, they work fine. Basically one piston works to turn left and the other works to turn right. BUT, if the tie bar isnt on, they dont work at all. They both go out... I always assumed the boat would steer with no tie bar or if one drive broke, the boat would still steer on one drive.

Not the case.

I'm wondering if the boats running that loose a tie bar, if the drag on the drives is enough to keep them in check. Kinda like towing a car with a towbar where the front wheels turn and straighten out by themselves?

Keith, I completely understand what your asking/saying-for the guys reading this and thinking it's ok because tie-bar is helping, each ram has 2 hoses, a push and a pull, I have twin rams on my boat (single engine) and i have bled all 4 hoses (IF I remember correctly) the stbd ram pushing isn't the only thing making the port retract. Some singles only have one ram, it pushes and pulls 1 drive, on thisboat each drive should act just like a single ram , single engine boat IF the tie bar isn't there. Now, the tie bar definately helps balance things out and tie things together. Now one answer that was posted that sounds plausible is the fact they are all tee'd together with one manifold and the ram extending would have to have resistance or be fully extended before the opposite starts retracting, sounds believable, Smitty

I lost a tie bar on a twin outboard boat with hydraulic steering, somewhere along a 15 mile straight run. I did not know it till I had come off plane and tried to turn into the marina and my cowlings about smashed each other. Trying to dock that day was, we will say interesting.

Yes, you get it.

Also, you came up with a great way to explain it. People think they will work like a single on each side. But it definitely doesnt. Can I re-plumb it a different way so each piston is isolated somehow?

You'd be trying to steer each drive seperately. No way you'd keep them both in sync perfectly. Or at least using a tie bar I don't see it possible without going to a huge undertaking/expense. I'd think you'd be creating more problems trying to reinvent the wheel for that almost non likely chance of a tiebar falling off.
Just install a second tiebar. Problem solved. :)
I take it you are running full hyd steering, no inner bar

Yes, full hydraulic. Two tie bars wont help if a gimble breaks.

Thats what I am trying to avoid.

Keith, did you lock one in place or extend it all the way to see if what US1 Fountain says is true? Its plausible that being the retract and extend on both rams are teed together that one with least resistance would move with no load on it and the second would retract when the 1st is done using up all the oil flow. You could also simply look at your plumbing inside your transom, your port ram's extend hose WILL be teed into the stb rams retract hose and stbd extend supply hose will be teed to port retract hose, sorta a criss cross, if they were backwards your boat would not steer at all as they would just fight each other, take a lok and lets us know, Smitty