Bravo gimbal housing corrosion

[Joesolta]

I removed my engine and transom assembly (2009 350 MAG SeaCore - 900 hours) to do a list of maintenance items e.g. leaky oil pan, gimbal bearing, coupler, bravoitis and the infamous leaking steering pin seal (stainless steering pin) etc. When I tore down the transom assembly, I found that there was quite a bit of corrosion around the steering pin seal and the lower bushing, to the point that a new seal will not stay in place. Also, about a third of the material around the bushing is corroded away. The gimbal housing is junk the way it is but given that a new housing is around $2000 and a transom assembly is nearly $3000, I was wondering if anyone knows of a machine shop that would do this kind of work - specifically welding/remachining on saltwater components. I know it's a longshot but the rest of the outdrive is in near perfect condition with no corrosion anywhere else.

 

[tank1949]

I removed my engine and transom assembly (2009 350 MAG SeaCore - 900 hours) to do a list of maintenance items e.g. leaky oil pan, gimbal bearing, coupler, bravoitis and the infamous leaking steering pin seal (stainless steering pin) etc. When I tore down the transom assembly, I found that there was quite a bit of corrosion around the steering pin seal and the lower bushing, to the point that a new seal will not stay in place. Also, about a third of the material around the bushing is corroded away. The gimbal housing is junk the way it is but given that a new housing is around $2000 and a transom assembly is nearly $3000, I was wondering if anyone knows of a machine shop that would do this kind of work - specifically welding/remachining on saltwater components. I know it's a longshot but the rest of the outdrive is in near perfect condition with no corrosion anywhere else.

Used fresh water alphas are fairly cheap on ebay. Bravos, not so much. Web search for used parts. I did!

 

[Joesolta]

I leave my boat in the water quite a bit and my first drive was an Alpha that turned into Alka Seltzer. I got the Bravo Seacore package as it was allegedly more resistant to corrosion. So far I am not impressed. I should have coughed up the cash for a bracket and an outboard.

 

[Scott Danforth]

I removed my engine and transom assembly (2009 350 MAG SeaCore - 900 hours) to do a list of maintenance items e.g. leaky oil pan, gimbal bearing, coupler, bravoitis and the infamous leaking steering pin seal (stainless steering pin) etc. .

that it technically a list of repairs. Maintenance is changing the zincs, performing an alignment every year, etc. if you change your zincs every 6 months like the manual states, it helps significantly with corrosion.

that aside, most radiator shops do aluminum welding. you will need to blast the surface, then grind away the pitted metal. from there, there are many small machine shops around the planet that can do machine work..... would help to know where you are

 

[Joesolta]

Scott, you're assuming a lack of maintenance. I'm in the PNW and use this boat year round as a commuter/fishing boat. In the hopes of avoiding breakdowns and big repair bills this thing is thoroughly maintained over and above the recommended intervals including frequent anode replacement, annual alignment checks, periodic testing of the bonding system and thorough lubrication of the driveshaft etc. Alas, it doesn't seem to be enough.

Welding and machining of that area is tricky business as the welding alloy has to play nice with the casting material and saltwater, also the bushing and seal bores would have to be cut with a custom made boring bar without much room for sloppy alignment or tolerances. I asked around because it would have to be someone familiar with outboards and sterndrives. JR Marine comes to mind but they are closed until April. Anyway, I decided to bite the bullet and buy a new transom housing. I will probably install a zerk fitting for the steering pin seal area

 

[Scott06]

Have friend who experienced similar corrosion with his bravo 3 - on lower unit and gimbal housing but on the outside Lower area of gimbal housing where transom gasket sits- he installed a second mercathode unit with two pucks on the transom on either side of the gimbal housing . Seems to have helped his situation (possible this is related more to stray current in his marina)

mercathode set up with the pucks is like $200 or $250 at most might be worth a try

 

[Joesolta]

I don't keep it in a marina. It's at dock by itself with no shorepower nearby. I'm suspicious because the area around the steering pin is the only area with corrosion. There is zero anywhere else. There is likely something more that can be done with anodes and I will have a second mercathode unit now that I'm buying a new transom assembly! Time to study up on galvanic corrosion.

 

[Scott06]

That’s a common area where the corrosion is seen. Somewhere I saw a merc service document where they sell a test probe so you can measure the galvanic potential of your drive , but I can’t locate it. Will keep looking

 

[tank1949]

I hate to pour salt into your wound, but having a saltwater kept I/O boat never turns out well, regardless of the BS that may have been told to you. Even the ant-corrosion OD paint sucks. Maintenance nightmares are one reason and the most often used to justify outboards, especially if boat is kept wet in salt water. Natural currents will eat away any metal, especially aluminum, that is bathed in saltwater. Yea the zincs do help. I have been boating in NW Florida since the 60s. I/Os were the greatest thing since sliced bread back then because of the power that could be unleashed by automotive V8s, until later on ODs started dissolving. You should consider building a lift or finding a dry storage marine near by. If you boat is saltwater cooled, remember that your motors insides may look like your ODs. But, Chevy V8s are MUCH cheaper than 250hps Yahmees. Good luck!!!!!!!

 

[Joesolta]

I hear you Tank. It's remarkable that after some 60+ years of I/O experience that some of these problems haven't been eliminated. We have the technology. Stainless steel and composites are getting cheaper all the time. I guess as long as the customer puts up with it and keeps paying, there is no incentive to improve. Anyway, When I re-engined this thing, I seriously considered an OB but aside from cost. I was concerned about raising the center of gravity on an already top heavy hardtop boat. BTW, I love Chevy V8s - reliable as a stone axe. If only someone would mount one vertically on an outboard bottom end!

 

[GasCan II]

Joesolta;Try JR Marine they do the machine work on Bravo gimbals. @ 440-946-8717 or 216-390-1330. I hope this helps.

 

[dingbat]

But, Chevy V8s are MUCH cheaper than 250hps Yahmees. Good luck!!!!!!!

Why is it that people always compare the cost to repower an I/o (new motor) to an entire outboard assembly?

If you want a real comparison, price an outboard short block and the cost/time to swap the power head to the same process for the i/o.

With the recent release of the 350 and 400 Hp outboards, good low hour 300 hp outboards can be had quite reasonably.

How much is a new 300 hp motor with a bravo drive cost installed?

Saving a couple of bucks upfront rarely serves you well in the long run

 

[Scott Danforth]

I hear you Tank. It's remarkable that after some 60+ years of I/O experience that some of these problems haven't been eliminated. We have the technology. Stainless steel and composites are getting cheaper all the time. I guess as long as the customer puts up with it and keeps paying, there is no incentive to improve. Anyway, When I re-engined this thing, I seriously considered an OB but aside from cost. I was concerned about raising the center of gravity on an already top heavy hardtop boat. BTW, I love Chevy V8s - reliable as a stone axe. If only someone would mount one vertically on an outboard bottom end!

Volvo did the composite drive

the issue with most boats purchased new are sold long before there are problems. its only the second and third owners that primarily experience corrosion.

true inboards are still the best for the moored boat, however even they need annual maintenance

Seven Marine takes the GM LSA motor with a proprietary gear set up to a ZF box and a custom foot to make an outboard.

 

[tank1949]

Volvo did the composite drive

the issue with most boats purchased new are sold long before there are problems. its only the second and third owners that primarily experience corrosion.

true inboards are still the best for the moored boat, however even they need annual maintenance

Seven Marine takes the GM LSA motor with a proprietary gear set up to a ZF box and a custom foot to make an outboard.

That's a monster!

 

[Scott Danforth]

today they are putting out 627hp.

they had an LS9 variant with over 707hp

the guy in the picture with the beer is the guy that first designed the heat exchangers over 10 years ago......:behindsofa:

 

[Joesolta]

The 7 Marine concept is interesting, and I would like one, but hugely expensive at $79K for the lowest model. The additional gear box to keep it horizontal adds a great deal of complexity and potential failure points. I was wondering why no one has a vertical engine version. I imagine there would be some concern with thrust bearings for the crank and maybe some issues with lifter and rocker oiling but those seem like relatively straightforward engineering problems. I know Honda uses vertical automotive engines and they make it work. And yes Volvo did have the XDP composite drives but they didn't work out well due to bad design rather than the materials I think.

 

[DWABoat]

At my company, we are fighting corrosion in Mississippi River (fresh water). We are working with a company called ElectroGuard in California. This company specializes in impressed current systems to completely counteract the corrosion chemical reaction. According to one of the engineers, if the system is properly installed and tuned, there will be NO corrosion on the drives or boat.
ElectroGuard also sells a test kit.
None of their stuff is cheap, but since we run dual Konrad 680 drives at about $15K plus each, it is cheap by comparison. (We must have I/O’s due to shallow water, no gasoline in my area, and the lack of reliable, powerful diesel outboards.)

I am not recommending ElectroGuard. The product may work or not. Whether their product works in the end, time will tell. They say they have hundreds of these systems out there and they work perfectly, when tuned. I am not a scientist. I am skeptical.

Since you are water-bound, you may want to reach out to ElectroGuard to talk about a possible solution that is custom designed for your boat, instead of the cookie-cutter Mercathode.

 

[Joesolta]

DWABoat, I'll check them out. I have to do a lot of reading on the topic.

 

[Joesolta]

Well, I finally completed this project after 4 months and about $8K in parts and materials. It took some unexpected extra time as I had to replace the transom core due to a bit of rot at the bottom of the V. Maybe I'm a masochist but the transom actually wasn't as bad of a job as I expected it to be. I have a question for you guys regarding OEM and aftermarket parts as I found two items defective out of the box. First was a coupler, made by Sierra. After spending a whole day unsuccessfully trying to align the engine, I pulled the whole works and found that the coupler spline hub to be off-center by about 1/8 - 3/16". Unbelievable. Also, I rebuilt the brass seawater pump, replaced bearings, seals, impeller and machined away the wear groves on the rear cover. On running the engine, I could only get max 2 psi water pressure. I pulled the pump and replaced the Sierra (again) impeller with an OEM part (stiffer, thicker rubber) and was able to get 16.5 psi. Anyone else with similar experience. I thought Sierra was a relatively reputable brand but I will be keeping away from their stuff from now on.

 

[Joesolta]

Well, I finally completed this project after 4 months and about $8K in parts and materials. It took some unexpected extra time as I had to replace the transom core due to a bit of rot at the bottom of the V. Maybe I'm a masochist but the transom actually wasn't as bad of a job as I expected it to be. I have a question for you guys regarding OEM and aftermarket parts as I found two items defective out of the box. First was a coupler, made by Sierra. After spending a whole day unsuccessfully trying to align the engine, I pulled the whole works and found that the coupler spline hub to be off-center by about 1/8 - 3/16". Unbelievable. Also, I rebuilt the brass seawater pump, replaced bearings, seals, impeller and machined away the wear groves on the rear cover. On running the engine, I could only get max 2 psi water pressure. I pulled the pump and replaced the Sierra (again) impeller with an OEM part (stiffer, thicker rubber) and was able to get 16.5 psi. Anyone else with similar experience. I thought Sierra was a relatively reputable brand but I will be keeping away from their stuff from now on.