300WE Rudder Port Frames

schwarz633

Member
Oct 1, 2019
35
Boat Info
1989 Weekender
Engines
Mercruiser 5.7 Inboard Straight Drive
As best I can tell, the rusty mild steel frames attached to the rudder ports are for the purpose of supporting the rudder assembly vertically. Is there an alternate method of doing this? I was thinking of placing a PVC sleeve between the bottom of the tiller arm and a SS washer sitting on top of the spud nut.

From the outside there's a little play in the rudders, but I don't know what's considered to be acceptable. Assuming the SS rudder stocks aren't worn, is replacing the port the only solution to eliminating this play?

DSCF1220.JPG
DSCF1221.JPG
 
I doubt the PVC sleeve would add much support. If it were me I'd be think of cutting the vertical section of the flat bar off a couple inches from the bottom and making new stainless L shaped pieces that I would thru bolt to the remaining cut off upper piece.
 
You want to be sure to have access to the packing nuts. Play in the rudders?
 
You want to be sure to have access to the packing nuts. Play in the rudders?
If I grab the end of the rudder it will move 1/8"-1/4" fore and aft. It just seems loose to me.
 
I doubt the PVC sleeve would add much support. If it were me I'd be think of cutting the vertical section of the flat bar off a couple inches from the bottom and making new stainless L shaped pieces that I would thru bolt to the remaining cut off upper piece.

How does this not provide much support? The white is PVC pipe and the gray is SS or bronze washer. The red would be removed.

DSCF1220x.jpg
 
Last edited:
If I grab the end of the rudder it will move 1/8"-1/4" fore and aft. It just seems loose to me.

1/8" sounds acceptable. 1/4" seems too much. Do they leak?
 
1/8" sounds acceptable. 1/4" seems too much. Do they leak?

I'll have to revisit that, it may be closer to 1/8" than 1/4". I didn't lay eyes on the rudder ports until the boat was hauled and in storage for a week. It looks like there's been some leakage, but that could be from any time between now and 1989.
 
If it's just surface rust you could wire brush the metal clean and paint with Rustoleum primer and gloss black using small brushes. I would start soaking the bronze gland nuts whenever you are in the engine room so you can adjust the rudder packings.
 
It appears that the steel bracket is providing more a lateral type support - helping to keep the rudder shaft vertical and not "tip" one way or the other under the stresses that the rudder imparts. Using that PVC piece won't do that.

There's probably any number of ways that you can fix and/or improve on this. But keep in mind that you got 30+ years out of it. That's not bad, at all, for mild steel. Also note, that the main reason it's rusting is because of the direct contact with the bronze metal - the mild steel is the less noble metal - galvanic corrosion. Ideally, there should be something like a nylon spacer/washer between the two.

If it's not "rusted away" - remove, clean, paint, reinstall - maybe with some Tef-Gel in between. Or, as Hot suggested - that SS L-bracket (with at least two bolts on each side) could work - make the vertical section of the L as long as the vertical section of the steel. You can use a nylon washer between those two pieces of metal, as well as the bronze plate.

But, considering they lasted this long, if you can still get that part, you could just put a new one in there.
 
If the intent was to provide lateral support, I think the design would have incorporated 4 legs instead of 2.
 
Those rudder A-frames are available new in 316 stainless steel on ebay. I replaced them on my 340EC last year. Sea Ray part #144030. Not going to eliminate any side to side play but I'd replace them before the old ones break.
 
If the intent was to provide lateral support, I think the design would have incorporated 4 legs instead of 2.
I was thinking about that, as well. But I wonder if it only really needs reinforcement in the two directions that the brace offers? Or, it could be that it's offering the vertical support that you're talking about AND some lateral support.

On the other hand, if the only thing it's doing is keeping the rudder arm from dropping... it seems over engineered? That's one of the reasons I was thinking there might be more to this that just vertical support. But maybe there's someone out there with more knowledge who can shed some light.

EDIT: Just looking at things again - and wondering outloud - maybe that large base plate is enough to counter the lateral stresses imposed by the rudder. But, we're also looking at something 30-years old - I wonder what the newer systems look like and if it's been found they need more/less/same reinforcing? I can't see how it would hurt to have that steel bracket fashioned the way it is - controlling the stresses near the top of the rudder shaft where "leverage" is the most helpful. Or maybe a 4-legged brace?

But in looking at the picture, it certainly looks like things have faired well over the years, the way it is. I'd be wary to get rid of that bracing without knowing FOR SURE whether it was important, or not, to have it.
 
Last edited:
Those look like the rudder supports on my 390.
 
Play in the rudder and the condition of the post would point me towards the packing. It's out of the water now is the time to remove the old and replace it with new.

There are four other classics near mine, ranging from 39ec to a 27sd none are newer than 1987. My 88 is the only one that has those supports. The 39 removed his completely after rusted completely out. None replaced or re engineered. The rudder post and packing assembly are very well built almost to the point of over engineered. It's a old boat. When or if you replace the packing carefully remove them, clean them up, repaint and place them back.
 
I talked with my mechanical engineer today down at the boats. I showed him the photo of your support and rudder post assembly. He agrees you should be replacing the packing while the boat is out of the water. As for the frames, they are only there to support the rudder post when you need to loosen the packing nut to redo your packing gland. Then the rudder arm sits on the top of the frame. Your frames are the original SeaRay frames, they are wide enough to get a packing wrench on the nut for tightening.
 
That frame carries the vertical load of the rudder assembly. There should be an oilite washer between the tiller arm and that steel frame which is the bearing. The only issue with this design is the packing gland which is also the rudder shaft bearing journal takes all of the moment load (rudder side to side forces imposed by the water and tiller loads) and tends to elongate; consequently, results in rudder lateral play then eventual packing leakage. Not that this is a bad design; it has endured. As stated earlier, this should be restored to include disassembly and inspection of the gland. As to replacing with a PVC sleeve - this would impose the tiller rotary forces onto the packing gland nut and make it difficult to adjust the gland; wouldn't be my solution....
 
Mott, is there a break down drawing of the assembly?

I know on mine there is no washer. I have to drop my rudders to pull my props. My shafts have a red disk that adds another inch on so to the length of the shaft. It forces me to drop the rudders. Luckily I have never had any issue with the packing, I'd have to be out of the water to change it.
 
Mott, is there a break down drawing of the assembly?

I know on mine there is no washer. I have to drop my rudders to pull my props. My shafts have a red disk that adds another inch on so to the length of the shaft. It forces me to drop the rudders. Luckily I have never had any issue with the packing, I'd have to be out of the water to change it.

The red disk are "Drive Savers". You could remove them and slide your shafts forward far enough that the props would clear the rudders.
 
I talked with my mechanical engineer today down at the boats. I showed him the photo of your support and rudder post assembly. He agrees you should be replacing the packing while the boat is out of the water. As for the frames, they are only there to support the rudder post when you need to loosen the packing nut to redo your packing gland. Then the rudder arm sits on the top of the frame. Your frames are the original SeaRay frames, they are wide enough to get a packing wrench on the nut for tightening.
I believe that the rudder is always supported by the frame with the tiller and bronze washer sitting on the top of the frame. Otherwise, you'd be relying on the friction of the packing to keep it from dropping down. With the weight and constant back and forth motion I'd think that would be sure to happen.
 

Forum statistics

Threads
112,945
Messages
1,422,741
Members
60,928
Latest member
rkaleda
Back
Top