Inboard steering: hard to turn against prop rotation

[1980Coronado]

I'm new to inboards and I have a question.

My 1980 Century Coronado tracks well. The steering wheel doesn't pull to the left or right at any speed. The boat does not have power steering. The wheel turns easily in both directions when sitting still, so there isn't a cable or lubrication issue. However, when running on plane, it is much easier to turn with the prop rotation to the right than it is to turn against the prop to the left. I'm quite sure this is normal behavior, but was wondering if there is anything that will help make it easier to turn against the prop rotation? It's not a big deal, but if you ever had to turn hard left to avoid contact, you'd better grab the wheel with both hands.

edit: I was wrong about this...my memory was bad. It's the opposite of what I remembered. It's hard to right....not left....argh!

 

[Fireman431]

Re: Inboard steering: hard to turn against prop rotation

Look into hydraulic steering.

 

[Lyle29464]

Re: Inboard steering: hard to turn against prop rotation

The no feed back system will make it appear you have a neutral setup but it sure sounds like your are really pulling right but it's not feeding back enough to turn your wheel. Some people fine tune the rudder buy placing a small wedge shaped zinc or just make a wedge from anything and bolt it to the right side of your rudder to let the water movement help the turn. You just grind it till your happy with the feel.

PS you need to use your normal speed while setting this up and making adjustment.

 

[Tahorover]

Re: Inboard steering: hard to turn against prop rotation

Your steering does have lube/zerks points at both ends of the linkage and a steering box made by Saginaw. Your box does take oil. Is your rudder stock? Did somebody install a smaller steering wheel?

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

Your steering does have lube/zerks points at both ends of the linkage and a steering box made by Saginaw. Your box does take oil. Is your rudder stock? Did somebody install a smaller steering wheel?

Everything is original......This is not a lube issue.....turns freely at slow speeds. Cable runs down the center of the boat.

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

The no feed back system will make it appear you have a neutral setup but it sure sounds like your are really pulling right but it's not feeding back enough to turn your wheel. Some people fine tune the rudder buy placing a small wedge shaped zinc or just make a wedge from anything and bolt it to the right side of your rudder to let the water movement help the turn. You just grind it till your happy with the feel.

PS you need to use your normal speed while setting this up and making adjustment.

Sounds easy enough.....so, multiple small wedges, or one larger wedge? How tall vertically should they be? 1/2"-1" tall x 1/4"-1/2" thick wedge? I assume that they should be attached to the trailing edge for better affect?

 

[Tahorover]

Re: Inboard steering: hard to turn against prop rotation

Everything is original......This is not a lube issue.....turns freely at slow speeds. Cable runs down the center of the boat.

I wonder what year they went cable, the newest Century I have worked on is a 78 and it had a box.

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

I wonder what year they went cable, the newest Century I have worked on is a 78 and it had a box.

We may be talking about the same thing. There is a box behind the steering wheel, under the dash. There is a cable that exits the box and goes thru the center of the boat under the engine. That cable runs through a bracket located somewhere near the prop shaft, and continues back to the rudder. I haven't looked at it since last fall...and haven't had the boat that long....so I'm going from memory.

 

[Tahorover]

Re: Inboard steering: hard to turn against prop rotation

You have a cable system and it's most likely a teleflex system. The Saginaw set up has a column that connects the steering wheel to the box. The box is mounted to the floor behind the foot rest. It has a pitman arm that connects to a rod. The rod is connected to the tiller arm astern.

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

Lyle

Can you explain what the "no feedback system" is? I've seen this terminology before, but not familiar with what it is physically/mechanically.

 

[Lyle29464]

Re: Inboard steering: hard to turn against prop rotation

The design of the gears cancels out the feedback from the rudder. If some one tries to turn your rudder by hand the wheel will not move. So you will not feel what is going on back there. So if you going down the river the prop torque of a left hand wheel will pull your stern toward the left. This does 2 things. It wants to make the boat turn right and it also puts sideways force on the rudder. If you had a tiller you would feel several pounds of torque. A wedge at the rear will tend to move the rudder back. I have seen people just cut a button zinc so you still have the bolt hole and install half of it. some just grind out a plastic wedge. start out big.

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

The design of the gears cancels out the feedback from the rudder. If some one tries to turn your rudder by hand the wheel will not move. So you will not feel what is going on back there. So if you going down the river the prop torque of a left hand wheel will pull your stern toward the left. This does 2 things. It wants to make the boat turn right and it also puts sideways force on the rudder. If you had a tiller you would feel several pounds of torque. A wedge at the rear will tend to move the rudder back. I have seen people just cut a button zinc so you still have the bolt hole and install half of it. some just grind out a plastic wedge. start out big.

Ok......gears I assume are in the steering box behind the dash?

Now.....I'm confused. A left hand prop makes the boat turn right? Mine is a RH prop and the wheel turns easy to the right. That's contradictory.

 

[Lyle29464]

Re: Inboard steering: hard to turn against prop rotation

lost me on that. I have seen rudders offset so you can take the shaft out from the rear. Maybe thats what is going on?

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

lost me on that. I have seen rudders offset so you can take the shaft out from the rear. Maybe thats what is going on?

No....just replaced a bent shaft....have to remove the rudder....no offset.

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

Lyle,

I've been doing some reading to check what I suspected. A powerboat will always tend to turn better in the direction the propeller rotates due to the propeller's torque reaction. So it is as I originally deduced, my right hand prop will cause the boat to turn easy to starboard (right), and harder to port (left). Now....I need to find someone who makes wedges to correct this, or machine some myself.

 

[tschmidty]

Re: Inboard steering: hard to turn against prop rotation

Don't be so sure the cable is fine. It's one thing for it to move easy when you are standing still, quite another when there is pressure against the rudder. When you actually load the cable with pressure, it will be pressing against the side of the cable and that's where it will become hard to steer.

 

[1980Coronado]

Re: Inboard steering: hard to turn against prop rotation

Don't be so sure the cable is fine. It's one thing for it to move easy when you are standing still, quite another when there is pressure against the rudder. When you actually load the cable with pressure, it will be pressing against the side of the cable and that's where it will become hard to steer.

I would expect it to be hard in both directions though if it was a cable issue. This doesn't feel like a cable grabbing. It just takes more effort to turn left. It turns smoothly, it just has more resistance against it turning left. I suspect it's just the nature of the beast, but wondered if there was something available to help ease the pressure on the rudder/wheel.

 

[Ned L]

Re: Inboard steering: hard to turn against prop rotation

A right hand prop should tend to make the boat turn more easilly to the left in forward. -- If you want to try a wedge, it doesn't need to be anything fancy. You can make a small wedge out of wood & epoxy it to the rudder (clean the surface to clean bronze first). It should take less of a wedge than you would think. I would start with maybe a 1/2" thick by 1 1/4" deep (fore & aft) by 2" long (up & down). If this is to much you can just trim it with a knife.

 

[DJ]

Re: Inboard steering: hard to turn against prop rotation

This phenom. is not unique to inboards, just a litlle more prominent. That is why MOST twin inboard set ups have counter rotating propellers.

You can mess with rudder tabs (similar to airplane rudder trim tabs) but it will be all trial and error.

If it really bothers you, you have a couple choices.

1. Hull trim tabs or Smart tabs will help but will not completely cancel out the torque.

2. Hydraulic steering will cancel out the torque feel. It will still be there, just not noticeable at the wheel.

I would go with #2.

BTW, the Coronado's are beautiful boats. True classics. Flat transoms and a prominent bow. I just don't like the "swoopy" stuff out there today. Especially, the "Euro" style transoms.

 

[tschmidty]

Re: Inboard steering: hard to turn against prop rotation

My point is a worn cable will exaggerate that pressure. Turning left and right puts pressure on different sides of the cable (push versus pull). "Pushing" with a cable is much harder than pulling and will put more wear and provide more resistance.

It's not the cause of the problem but could certainly exacerbate it.