I broke the bolt for my anode; now what do I do??

[DBreskin]

I am preparing for my first season with my new-to-me boat. It has a 1992 OMC Cobra 5.8L drive. The anodes are old, pitted, and the PO had the bright idea to paint them so they're not doing much in the way of protection.
I tried to remove the bolt for the anode in the lower section of the drive and the bolt snapped like a twig. The old anode is out, but the end of the bolt is still in it's hole. It looks like there is blue thread sealant around it.

How can I get it out? The only thing I can think of is to drill a hole in it and try to use a bolt remover (easy-out) but I'm afraid the thread sealant will be too hard to break free.

Is there any risk to using the boat for a day in fresh water with it in this condition?

Picture is attached.

 

[Don S]

Re: I broke the bolt for my anode; now what do I do??

EDIT Disregard, I was thinking the bolt came in from the top.

 

[glennwolf]

Re: I broke the bolt for my anode; now what do I do??

water will always cause and electrochemical reaction. One use will not kill it butt get the old bolt out and replaced ASAP. DO NOT!! I REPEAT!!! BREAK AN EASY OUT OFF WHILE REMOVING THE BOLT!!! You can drill a bolt but the easy out is too hard to drill.

 

[DBreskin]

Re: I broke the bolt for my anode; now what do I do??

The only thing I can think of is to drill a hole in it and try to use a bolt remover (easy-out) but I'm afraid the thread sealant will be too hard to break free.

Can anyone tell me how deep the hole is for this bolt? Does it open into the exhaust passage? I don't want to risk damaging my housing.

I also want to find a way to drill without removing the prop shaft. Maybe I can use an angle-head drill.

 

[shay_mcquaid]

Re: I broke the bolt for my anode; now what do I do??

Here's what I would do:

get access to a 90 degree drill motor or at least an angle attatchment if you can't get straight on it.

Depending on the hardness ofthe bolt:IF possible start with a carbide rotary file (1/8 shank ball shape ) and start fileing in the center of the bolt to make you a place to start the drill. Start with max 1/8. Gonna need some good drill bits. (maybe lots)Use slow turning speed with lots of pressure to cut the hard steel. Softer steel will drill easily. Hard to say how deep to go. 1/2 inch minimum???
Progressivily drill the hole bigger and bigger until the largest easy out that is just under the bolt diameter will fit. Make sure you get a good bite with the easy out. Tap it in with hammer. Make sure your easy out is fresh. (at least grind a bit of the bottom if it's been rounded up a bit from use. Best thing is to get a new one.
Worse case the walls of the bolt will eventually get thin enough to collapse with punch and hammer. Prolly need to run a tap thru your threads.
I suspect,hopefully, that it isn't a hardened bolt since I guess it's not structural
Remember that if you spin the drill bit on hard steel it's probably toast and just get a fresh one. Once the cutting surface is dull it's done.

 

[HT32BSX115]

Re: I broke the bolt for my anode; now what do I do??

It's difficult to tell from the picture but is that the anode on the housing near the trim-fin above the prop?

Can you get to both sides of the bolt? The bolt will most likely be a SS bolt so you need a bit that is harder than the old bolt or you will be cussing it.

can you get a tap in there?

Is there any risk to using the boat for a day in fresh water with it in this condition?

You can use it in fresh water as long as you want.... if you're not leaving it in the water.

You could even use it in salt as long as you pulled it out and flushed/rinsed it off. The anodes are really there for extended sitting in fresh or salt. I think it would take years of using the boat daily in fresh water if you pulled it out, flushed/rinsed and trailered it every day to cause any significant corrosion.


Cheers,

Rick

 

[bruceb58]

Re: I broke the bolt for my anode; now what do I do??

I can't remember what other anodes are on that drive but if there are others and you are only using it in freash water and not leaving it moored for extended periods of time, I wouldn't worry about replacing it.

After all, its an OMC...how long is it going to last anyway?

 

[TyeeMan]

Re: I broke the bolt for my anode; now what do I do??

As stated above, sort of, , can you separate the lower unit from the rest of the drive and access the bolt from the top? If you separatet the lower unit and there is not a through hole can you accurately measure out, and drill down right on top of the broken stud? As long as you don't drill through anything important.....
Just a thought.

 

[Fishermark]

Re: I broke the bolt for my anode; now what do I do??

I can't tell from your picture if this method is practical or not - but a good way to get out broken bolts like that is to weld a nut onto the end of the broken bolt. The welding process adds the heat - then you can douse it with some penetrating oil and have a "head" on the bolt that you can grab and turn with vise grips or whatever. Of course you need a good mig welder....

 

[DBreskin]

Re: I broke the bolt for my anode; now what do I do??

Shay - thanks for the advice, I guess that's what I'll do.

HT32BSX115 and TyeeMan - I was hoping to avoid disassembling the drive.

bruceb58 - It's 18 years old. I hope to get another 18 years out of it with proper maintenance. Do you think the Cobra design is inferior to a Mercruiser of the same vintage?

Fishermark - There's not enough clearance to get in there to weld Even if I could, the housing would melt before the stainless bolt got hot enough to weld.

Thanks everyone for your input. Tomorrow will be my first time taking the boat out. I'll let you all know how it goes.

 

[bruceb58]

Re: I broke the bolt for my anode; now what do I do??

It's 18 years old. I hope to get another 18 years out of it with proper maintenance. Do you think the Cobra design is inferior to a Mercruiser of the same vintage?

I was kinda joking. They definitely have their weaknesses. The main problem will be part availability and getting people that know how to work on them. Biggest weakness is the crummy shift cable that may someday cause you to toast the dog clutch when it fails.

I used to own one. I would not buy another.

 

[Lou C]

Re: I broke the bolt for my anode; now what do I do??

I think that the bolt for that anode threads into the upper gear housing...so to remove it you'd probably have to spit the upper and lower gear housings...and if you are not leaving it in the water then you are not at all likely to have a corrosion problem. I'd leave it be until you need a repair that necessitated splitting the upper and lower and fix it then...I'd had to get some seals replaced in mine over the years and one of the repairs involved splitting the upper and lower...
As far as the Cobra...well mine is 22 years old and still going strong...they need a mechanic who knows how to adjust then and a supply of parts..the problem is as time goes by both are going to become less available...but I'd just enjoy the boat and not worry about that...BTW mine is very similar to yours...it's a big 20' actually 20'9" which is about a foot longer than the modern 200 Horizons...and this hull design is deeper and more roomy as well...Find a good OMC mechanic and enjoy the boat...


BTW...this is why OMC notes that most bolts on the outdrive are supposed to have OMC gasket sealer put on the threads...this seals out the water and reduces corrosion...you can also use marine grease...I have a salt water boat in the salt 6 months out of the year and that is how I keep things from corroding....the OMC gasket sealer is also known as Permatex Aviation Sealer...goopy brown stuff that never hardens...works great as does the OMC/Bmbardier triple guard grease...

 

[DBreskin]

Re: I broke the bolt for my anode; now what do I do??

So I took the boat out for the first time today. It ran beautifully...until the drive seized.
I'd been out about 40 minutes at various speeds (topped out at 47 on GPS) and stopped for lunch. We were cruising back at about 1100 rpm when the motor died. I tried to start it again with no luck. I raised the doghouse and tried to start it while looking at the engine; the starter torques the engine over a bit but there's no rotation from the crank pulley.
I'm guessing something in the drivetrain has seized. If I'm lucky it's the gimbal bearing. If I'm not lucky it's the vertical drive. I guess I'll start tearing it apart tomorrow.


Once I get it open I'll probably start a new thread asking for advice.

 

[Lou C]

Re: I broke the bolt for my anode; now what do I do??

Did someone recently change the gear oil and pump it in from the bottom most plug and not get 64 oz in there....if so that's not the right way to do it....there have been a lot of threads on the proper oil change for the Cobra drive but that's only one reason for it to fail....did you check the gear oil level before running the boat....

 

[DBreskin]

Re: I broke the bolt for my anode; now what do I do??

Lou, I had it winterized by a boat mechanic who was recommended to me. I'd heard about the correct oil fill procedure and questioned the mechanic about it; he assured me he knew how to do it.
I ran the motor on muffs in my driveway a few times, for a total of about 10 minutes, and had checked the drive oil level before going out.

My plan for today is to build an outdrive stand; remove the plug and drain the drive oil (checking for metal fragments while doing so); and open the top of the gearcase to check inside. I'll likely start another thread once I find out what has happened.

 

[fuzzybob]

Re: I broke the bolt for my anode; now what do I do??

Did you try pulling the spark plugs and turning the engine by hand??

 

[Lou C]

Re: I broke the bolt for my anode; now what do I do??

I built one out of some left over wood a few years ago...once you get it off then you can see if you can crank the engine over with the drive off then you will know for sure...As a matter of fact I can actually move the engine by hand (I do this when checking the point gap to get the rubbing block on the high point of the cam)...I grab the alt belt with one hand on each open section of it and then I can pull one side and push the other and this will move the engine a few degrees....just enough to tell you if the engine is locked up itself....
Did you hear any noises from the drive running it on the water hose...sounds like you checked the gear oil level that was OK...sometimes a drive could have had an impact in the past that bent the prop...and a gear was fractured...but the drive still worked OK...but sooner or later that gear gives out and grenades the drive...there was an article by a marine surveyer somehwere that discussed this...

So now you have to decide...do you have the Cobra rebuilt....buy an already rebuilt unit...or change it over to an Alpha using the SEI conversion kit that lets you mount an Alpha on a Cobra transom mount...most would say go for this...I'd consider it but I'd want to find out from users how well this works over time...Then there is also a Cobra to Volvo conversion...but the drive cost alone might make that impractical....

 

[bruceb58]

Re: I broke the bolt for my anode; now what do I do??

Before you start, check to see what the oil level is right now.

 

[smokeonthewater]

Re: I broke the bolt for my anode; now what do I do??

check out your engine too.... might not be the drive at all.....

 

[DBreskin]

Re: I broke the bolt for my anode; now what do I do??

Thanks to everyone who has offered advice. I removed the outdrive today; the motor turs over now, but the outdrive is still seized. I am starting a new thread for this problem.