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OMC should steering support bracket be sealed?

theydrewa31

Regular Contributor
Hello again all!

Simple question here. Working on an OMC cobra 4.3L (model 432APRGDP). I took off the lower steering support bracket today (part number 912391) in order to remove the gimbal ring and replace the seals which had deteriorated, and as long as I am at it I will be replacing the bushings and painting the transom shield, and gimbal ring as well. When I removed the bracket the cavity inside seemed to be filled with water. The area filled with water is shown by the purple arrow in the picture below. I was considering using something like form-a-gasket sealant when I reattach this part to prevent water from getting in there in the future. Is this a good idea? Keep in mind that she hasn't seen water in at least 5 years meaning that water has been there for a long time, so anything that goes in there is likely getting trapped for a very long time. I can't imagine that it is good to be getting water in there, especially since I will be using this boat primarily on saltwater. Is there something other than Form-A-Gasket that is better for the marine environment that I should be using instead? Any opinions or information will be greatly appreciated!

Note: the parts diagram does not show a gasket for this part.

Thanks in advance for any help!

Gimbal 1 JPEG.jpg
 
I'm assuming that water in there is a bad thing. It does get down to freezing here a couple times a year, so I would assume having water in there that could freeze and expand would be a bad thing. I'll take a "best guess", or an opinion on this one; anything helps! Furthermore I can only assume it would be the cause of corrosion over time.
 
Including a parts diagram to aid in understanding what you are looking at. The part in question is circled in red.

Note: The cavity does not lead to anywhere and there is no outlet. Any of the water that came in did so through the bolt holes or between the mating surfaces on the bottom of the transom shield and the top of the bracket. This is the bottom bracket that holds the lower bearing of the gimbal ring in place.


Gimbal 5 JPEG.jpg
 
do you have a factory OMC shop manual for your engine/drive package? If not I suggest getting one, they are very detailed and most likely would answer the questions you have. Look here:
 
I have the Seloc manual on hand. The section for reassembling the transom shield mostly deals with the bellows and such after servicing the outdrive. Nothing as deep as I have gone which at this point is full dis-assembly. I'm going to look into those manuals and see if they have anything that can help me.

At a glance I don't see my model number; but I'll dig deeper later on while the paint on the outdrive is drying.

Thanks for the help!
 
do you have a factory OMC shop manual for your engine/drive package? If not I suggest getting one, they are very detailed and most likely would answer the questions you have. Look here:
By the way, I have roughly the same model as you I think. I have the 4.3 manufactured in 86'.
 
Yep mine is a 1988, I have never had to take it apart to the level you have there, so I don't know if water in that area could cause a problem, but I'll take a look at my shop manual and see if anything about it is mentioned.
OK took a look. It says nothing about sealing that lower support for the gimble ring, as you noted there is no gasket there, mine has been in freezing conditions every winter and nothing has ever cracked. I would grease all the bushings and fiber rings with OMC triple guard grease. Even though mine has been in salt water and looks terrible, there is just normal play in the steering and I have had no real need to take it apart, other than pulling the drive every season to check the bellows etc.
As far as buying the right manual, there are some differences but not major, I 'think' the transom mount assembly was slightly changed after '89 but not sure. I have a spare assembly in my garage that I bought from a freshwater region via ebay that I have harvested a few parts off of (trim cylinder parts, had to rebuild both of them this spring). I'd call them tell them what you have and see what's the closest match, it is worth having if you are keeping the boat and are doing a lot of work yourself.
 
Yep mine is a 1988, I have never had to take it apart to the level you have there, so I don't know if water in that area could cause a problem, but I'll take a look at my shop manual and see if anything about it is mentioned.
OK took a look. It says nothing about sealing that lower support for the gimble ring, as you noted there is no gasket there, mine has been in freezing conditions every winter and nothing has ever cracked. I would grease all the bushings and fiber rings with OMC triple guard grease. Even though mine has been in salt water and looks terrible, there is just normal play in the steering and I have had no real need to take it apart, other than pulling the drive every season to check the bellows etc.
As far as buying the right manual, there are some differences but not major, I 'think' the transom mount assembly was slightly changed after '89 but not sure. I have a spare assembly in my garage that I bought from a freshwater region via ebay that I have harvested a few parts off of (trim cylinder parts, had to rebuild both of them this spring). I'd call them tell them what you have and see what's the closest match, it is worth having if you are keeping the boat and are doing a lot of work yourself.

It looks like mine is an 88. I forgot that the boat is an 85 but had gotten a swap to this one at some point, so it looks like we have the same model engine/ outdrive. I ordered the manual. Thanks for linking that website.

Thanks for checking what the manual says for me! The manual I ordered won't get here until late next week, and I am trying to get as much work done on this project as I possibly can while I have the time, so not waiting for that information until I got the manual is keeping my project moving!

You are awesome Louc! Thank you so much!
 
Without having any information in the manual about it I am leaning towards sealing that part when I re-assemble the transom shield. Perhaps the lack of information was an oversight, or possibly just that the parts have warped over time. Either way, I feel like there really shouldn't be water collecting in there, and my logic says that sealing it up can't hurt as long as I don't use a gasket maker that has copper in it. At this point I feel like it comes down to a matter of opinions so I'll gladly accept any opinions on the matter.

As far as the gasket maker, I am considering using Permatex Anaerobic Gasket Maker, link below. It specifically states that it is safe to use for aluminum parts, and easy to disassemble parts in the future if needed, so it sounds like an ideal product for the application. All that said if there is something else out there specifically designed for marine applications, or something else you guys have used I'm open to any suggestions you might have.

https://www.permatex.com/products/g...alants/permatex-anaerobic-gasket-maker-50-ml/

Thanks again gentlemen!
 
I see no problem with using that, as long as there isn't a drain hole that could be blocked by it. Check carefully.
Here's a tip, on any bolt on the outdrive or transom mount, coat the threads with OMC/Evinrude gasket sealer or Permatex Aviation. This will keep water out of the threads and prevents bolts from seizing up which is a major problem with outdrives used in salt water. Water pump bolts, anode bolts, the bolts that hold the upper and lower together, etc. Also thermostat housing bolts and to seal the gasket. Oh and if you ever have to split the upper and lower and can't get them apart (common) I have a trick for that too. Coating the bolts like this, over 20 years in the salt, I have not had a bolt I couldn't get off. And I have found even on fresh water used drives, the bolts seize too if not coated. This one thing will make your life 100% easier. When you can find it on Amazon, buy big size of the Evinrude gasket sealer.
Overall, I have been happy with the Cobra, they hold up well when maintained, as good as if not better than Merc or Volvo, I have a lot of spares to keep it going.
PS if you ever have to replace that one piece V6 exhaust system, I have all the part numbers to convert it over to the later style using Barr Marine aftermarket manifold and elbow kit, and Volvo Penta OEM exhaust pipes and hoses. Not cheap but necessary here in the salt. About every 7 years or so. My engine is on exhaust system # 4.
 
4.3 with new exhaust system.png

1988 4.3 after installing remanufactured cylinder heads, and a new center riser exhaust conversion. Barr Marine aftermarket + Volvo Penta exhaust 90* pipes and hoses....about $1200 when I did it in 2017....
 
It looks like you went to the 9s there Louc! Good work!

I see no problem with using that, as long as there isn't a drain hole that could be blocked by it. Check carefully.
Here's a tip, on any bolt on the outdrive or transom mount, coat the threads with OMC/Evinrude gasket sealer or Permatex Aviation. This will keep water out of the threads and prevents bolts from seizing up which is a major problem with outdrives used in salt water. Water pump bolts, anode bolts, the bolts that hold the upper and lower together, etc. Also thermostat housing bolts and to seal the gasket. Oh and if you ever have to split the upper and lower and can't get them apart (common) I have a trick for that too. Coating the bolts like this, over 20 years in the salt, I have not had a bolt I couldn't get off. And I have found even on fresh water used drives, the bolts seize too if not coated. This one thing will make your life 100% easier. When you can find it on Amazon, buy big size of the Evinrude gasket sealer.
Overall, I have been happy with the Cobra, they hold up well when maintained, as good as if not better than Merc or Volvo, I have a lot of spares to keep it going.
PS if you ever have to replace that one piece V6 exhaust system, I have all the part numbers to convert it over to the later style using Barr Marine aftermarket manifold and elbow kit, and Volvo Penta OEM exhaust pipes and hoses. Not cheap but necessary here in the salt. About every 7 years or so. My engine is on exhaust system # 4.
Motor Pull.jpg


As far as the motor side of things go I have only started. All I have done so far is pull out the motor. I had to do that as the transom wood was rotted down to nothing. The previous owner tried to ignore a lot of things he shouldn't have. As far as the motor goes started up nice and ran when I got it. It was probably the only part of the boat that he seemed to do anything to with regards to maintenance. I assume he had basic mechanic knowledge because it shows signs of maintenance here and there, but that's where his maintenance started and ended. He ran the outdrive with no oil and completely melted the gears, which is why I have been doing so much work on that. Replaced all of the gears and bearings on the outdrive.

When I get into the motor I plan to replace most of the gaskets. It was clearly leaking oil from somewhere but not sure exactly where. With regards to the exhaust the only problem I can see is that one of the internal dampers (or flappers, not sure what you would call them) had become dislodged and needs to be replaced. This boat is bleeding me dry so I am trying to keep everything as cheap as possible from here on out so upgrading the exhaust won't be in the cards until it needs attention later on if/when it happens to have issues. If there is anything else that is inexpensive that I should keep an eye on while I'm working on the motor let me know!

One thing I was curious about was the mounting surface for the motor. Whoever installed it used plywood to raise the height of the motor to get it to align with the hole for the outdrive. The plywood was falling apart so I was planning to replace that with something else. Any recommendations for that? I'll eventually have some marine grade plywood when I get around to replacing the transom wood. I will have some scraps leftover so I could use that and cover it in the marine epoxy that will also be used for the transom wood. Do you think that might work? I'll try to snap a picture of the mating surfaces later and I'll probably start a new thread for that when I do just for the sake of others who might be able to be looking for that kind of information.
 
Regarding the plywood thats falling apart - if you just need 'shims' under the motor mounts, depends upon how much you need and if the surface under them is solid...the mounts usually have a decent amount of vertical adjustment...ideally, when you reinstall things, set the motor mount adjustment to the mid-point, vertically, and then figure out how much 'shim' you need...I would use a piece of oak (soaked in resin) if you want to use wood...plywood is 'soft' and compressed pretty easy...or a handmade fiberglass shim if you have any matt and resin leftover from the other repairs...scrap piece of aluminum plate would work but you would want to make sure to coat them to minimize any galvanic activity...
 
You can use the Permatex Aviation for what you were thinking of….
The motor mounts well I’d carefully see what is left of them but in order to get the height correct you need to do the transom first. Finish the transom, re mount the transom mount, lower the engine onto the rear mounts then level the engine out over the mounts & see how much you need to build them up.
 
Oil leaks, check your PS system (the actuators mounted on the transom mount) the actuators leak when they get to be 20+ years old. Other common leak spots are the oil pressure sending unit (on the rear wall of the block behind the distributor) and the lower rear corners of the valve cover gaskets behind the exhaust manifolds. About the exhaust, in fresh water you may never need to replace them. Just check to make sure you’re not getting water in the cylinders or oil….
 
Regarding the plywood thats falling apart - if you just need 'shims' under the motor mounts, depends upon how much you need and if the surface under them is solid...the mounts usually have a decent amount of vertical adjustment...ideally, when you reinstall things, set the motor mount adjustment to the mid-point, vertically, and then figure out how much 'shim' you need...I would use a piece of oak (soaked in resin) if you want to use wood...plywood is 'soft' and compressed pretty easy...or a handmade fiberglass shim if you have any matt and resin leftover from the other repairs...scrap piece of aluminum plate would work but you would want to make sure to coat them to minimize any galvanic activity...
Good point about the compression of plywood. I did notice that the plywood I removed had compressed where the motor mounts had been sitting. My first thought was to use a hardwood such as oak, I was only considering the marine ply because I knew I would have some on hand, but for the small amount of wood needed there I can definitely afford a small amount of oak.

With regards to fiberglass I would have to purchase some specifically for the mounts as this is an aluminum boat so I won't be needing any fiberglass anywhere else on the boat. Since I don't think it would be cost effective to get such a small amount of fiberglass I think oak will be a better option for me.

I was thinking more like anodizing the plates...or hardcoating them at a minimum...

Not a bad idea, but I don't have any of the equipment for anodizing. If I did that I would probably need to take it somewhere to have it done. Any idea of the price range for something like that? This boat needs waaay more than I initially thought it would. It is really bleeding me dry, so I will honestly be doing everything as affordably as possible anywhere I can which is honestly a hard thing for me to do, as I usually go the extra mile on just about everything. At this point this has turned into a massive project and I just need to stop the bleeding.

I am going to start a new thread for the motor mounts and include some photos. The motor mounts are clearly a different subject matter from my original posting, and I do my best to keep separate threads for different subjects in consideration of future forum readers who might find the subject matter useful. It just makes the information easier to find when the thread title matches the subject matter. As a fella who has benefited greatly from the postings of others on here, and at times found it very difficult to find the information I needed, I try to do my best to keep it organized for others.

Thanks so much for the advice Mako! This is very helpful!
 
You can use the Permatex Aviation for what you were thinking of….
The motor mounts well I’d carefully see what is left of them but in order to get the height correct you need to do the transom first. Finish the transom, re mount the transom mount, lower the engine onto the rear mounts then level the engine out over the mounts & see how much you need to build them up.

Thanks Louc! I'll be using the Permatex Aviation!

And good point with regards to the mounting procedure, I'll finish the transom first!
 
Oil leaks, check your PS system (the actuators mounted on the transom mount) the actuators leak when they get to be 20+ years old. Other common leak spots are the oil pressure sending unit (on the rear wall of the block behind the distributor) and the lower rear corners of the valve cover gaskets behind the exhaust manifolds. About the exhaust, in fresh water you may never need to replace them. Just check to make sure you’re not getting water in the cylinders or oil….

Is there a way to check them while they are dis-assembled from the transom shield? I currently have them removed from the transom shield. As I am currently in process of servicing all of that and re-painting those components, including the actuators. I actually have some more questions about that system so I am going to start a new thread for that to keep things organized for anyone else who needs the information.

I'll keep an eye on the oil pressure sending unit, and I already planned on replacing the valve cover gaskets.

With regards to the exhaust manifolds, I am pretty sure this has only ever been run on fresh water. I picked this boat up in Flint, Michigan, so it was a Great Lakes boat. It could have seen saltwater once or twice but I highly doubt it. I actually towed this 22' boat on dual axel EZLoader trailer all the way accross country. Went from Flint to Washington DC where I had a friend's house to sleep at. Then down to just outside Atlanta, Georgia where I had another friend's house to sleep at and a place where I could repair the non-functional trailer brakes. Thankfully I was able to fix the brakes there because I hit hurricane remnants in Oklahoma and hydroplaned. Between the heavy rain, and the mountains of Arizona I don't think I would have made it in one piece without the brakes. So all of that was to say this boat traveled from the Great Lakes, then coast to coast to end up in San Diego where she will now be a saltwater girl.

I am starting a new thread for the motor mount questions so please keep an eye out for that.

Thanks again Louc! You have been a big help with this!
 
As far as checking the P/S system not hooked up to the steering arm you could try starting the engine ans see if it leaks but it’s not a true test until it has the load of moving the drive against it. If the control valve leaks it can be rebuild with a kit for classic Mustangs & Corvettes, believe it or not they and the boat used the same Bendix power assist system. There aren’t kits for the hydraulic cylinder though. Used units are available on eBay.
The exhaust should be fine now since it came from fresh water. However if you use it in salt water you will have to change them after 5-7 seasons or so. They rust internally and will let salt water into a cylinder & ruin the engine. Those one piece units have been NLA for a long time so that’s why I converted mine over back in ‘17 to a standard aftermarket 2 piece set up. Next fall I might have to replace the elbows the manifolds are probably still good…
 
As far as checking the P/S system not hooked up to the steering arm you could try starting the engine ans see if it leaks but it’s not a true test until it has the load of moving the drive against it. If the control valve leaks it can be rebuild with a kit for classic Mustangs & Corvettes, believe it or not they and the boat used the same Bendix power assist system. There aren’t kits for the hydraulic cylinder though. Used units are available on eBay.
The exhaust should be fine now since it came from fresh water. However if you use it in salt water you will have to change them after 5-7 seasons or so. They rust internally and will let salt water into a cylinder & ruin the engine. Those one piece units have been NLA for a long time so that’s why I converted mine over back in ‘17 to a standard aftermarket 2 piece set up. Next fall I might have to replace the elbows the manifolds are probably still good…
Thats cool about the Corvette and Mustang parts. Unfortunately the entire system is completely disconnected at the moment. Motor out, hydraulic cylinder out, actuators dethatched and awaiting fresh paint, fluid manifold and lines all currently removed. I guess you can say I went pretty deep on this project. Perhaps a little deeper than I needed to, but honestly a lot of it felt like it needed attention after years of neglect. Since I plan to take this thing offshore I really didn't want any variables that could leave me stranded. Having Seatow pull me back into port is the last thing I want!

I see now why you upgraded the exhaust. I had no idea they were NLA. Are the merc exhaust systems better at keeping water out than the OMC?
 
Well it depends on which one; and if you’re using it in salt or fresh. In freshwater anything will last, in salt water unless it’s flushed after each use figure on 5-7 years replacement. Merc made a wet joint exhaust (similar to OMC & Volvo) then they came out with the dry joint in 2002. This eliminated the failure prone gasket between the manifold & elbow by moving the water passages outboard of the exhaust passage. However in salt water use they can still rust thru. I went with the later OMC/Volvo style (wet joint) because I knew that those parts would line up with the original OMC Y pipe. So no water leaks. I would have liked to switch to the Merc system but too many unknowns regarding if it would all line up and fit without water leaks. I use an inspection camera that scope the exhaust at the end of each season and that helps with deciding when it needs to be replaced. So far after 5 seasons they still look good inside.
Many OMC parts are NLA. These units while good haven’t been made in many years. Company went bankrupt in 2000, Bombardier in Canada bought the assays and Evinrude outboards which they also discontinued. I have kept mine going with a combination of of OEM, aftermarket and used parts.
 
I use an inspection camera that scope the exhaust at the end of each season and that helps with deciding when it needs to be replaced. So far after 5 seasons they still look good inside.
That's not a bad idea. I'll have to pick up one of those inspection cameras!

Many OMC parts are NLA. These units while good haven’t been made in many years. Company went bankrupt in 2000, Bombardier in Canada bought the assays and Evinrude outboards which they also discontinued. I have kept mine going with a combination of of OEM, aftermarket and used parts.
Honestly if the exhaust system does fail on me I'll probably sell off the remaining components and convert this to an outboard setup with a swim deck/ outboard mount conversion kit. I know, that's probably considered blasphemy in the OMC forum! I stayed with the OMC as I thought it would be the more affordable and easier option to work with for now. Hopefully I hit the lottery before then so I can afford a twin set of outboards!
 
I like outboards and that will likely be my next boat but compared to inboards the late model 4 strokes are VERY expensive to repair/rebuild. The clsssic small block Chevrolet is about the simplest, cheapest, easiest engine to repair/rebuild that ever was. Less the exhaust my top end overhaul cost $650 parts. That ain’t happening on a 4 stroke outboard. If you convert to Merc you will never have trouble finding parts new or used. Cheapest way to do boating that there is. Now if OMC was still in business and all parts available for sure I’d stick with it: had great luck with it 20+ years! All in salt water.
 
Not a bad idea about the merc setup. For me though I'd eventually prefer an outboard. I am setting this thing up for fishing and It would be nice to have more deck space. Being that it has the cabin in the front there is really only going to be space for 3 people on the deck after I put in bait tanks. I really struggled with the decision of whether to do the conversion while I was doing all this work but eventually just decided that pound for pound (or rather horse power for horse power) the outboards are just too expensive for me right now, like you said. Who knows though, I'll probably never get around to it and if its not broken don't fix it right?
 
Honestly I would go outboard only because:
I moor my boat in salt water for a 5 month season and outboards are less work in that kind of use; painting the drive & transom mount is a hateful job every spring
Going to be 70 years old this coming fall so crawling around the bilge to winterize one of these is getting real old, advantage outboard
 
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