HELP-Mercruiser Sterndrive issue

[bigdog]

I have an issue with my Mercruiser Alpha Sterndrive, which I hope someone can give me some information ?

While covering the the boat up for the winter, I was checking the Sterndrive.
I noticed that a rubber flexible hose located at the bottom back of the sterndrive was torn in several places. When I say "hose", I think it's actually considered a "Bellow", about 3 inches in diameter.

I believe this may be the "Exhaust Bellow" ? Can someone verify my assumption. Also, can I live with this, in this condition, and operate the engine, without causing any harm to the engine or creating future issues?

[TomC]

There are 3 of them in your drive. There is one for the exhaust, the U-Joint, and shift cable. you need to repair it before next season. These keep water out from where it shouldn't be... you run the risk having your boat sink if you use it the way it is, especially if your u-joint bellows is the torn one.

Bellows replacement is not really a DIY job, although it is possible - several special tools are required (see www.sterndrives.com/mercruiserhelp.html). A marina can to the job for $500-$600.

[Island Girl]

Having had torn bellows on two different boats... get it repaired or it will be much more costly.. and it is so much fun riding full blast to keep the water from pouring into the back of the boat ... and speeding down a canal to get the boat hauled out quickly... Ah... such an adventure!

[bigdog]

I understand the seriousness of replacing the U-Joint or shift cable bellows, but how would the "exhaust bellow" cause me a concern ? Or the possibilty of the boat taking on water ? Maybe I just don' understand the mechanics of this part ? Thanks !

[jrc]

Get it checked out. Sinking is really a mess.

I've heard that Bravo stern drives can be run without the exhaust bellows and some come with a special single ended bellows. But I'm not sure on Alpha's. Even if sinking isn't an issue, water backing up into the engine might be.

The other question is why are there holes. If the rubber is old and brittle it can crack. In that case if the rubber on the exhaust is too old, the other bellows are probably too old as well.

If nothing else, a phone call to a reputable marine mechanic may answer the specific question. If the boats on a trailer, why not run it by a mechanic now or before you launch in the spring.

[Blue Thunder]

BigDog,
As stated earlier, there are 3 bellows. The largest one is the driveshaft/CV joint and is more like 4 to 5 inches in diameter. It's also the top one (from bottom to top). If it's cracked you should be able to stick your fingers in and feel the driveshaft that connects to the gimble bearing. Depending on how long it was cracked, your gimble bearing is probably junk. Don't fool around with it, just have it replaced or you will be stranded out on the lake when it decides to fail. The exhaust bellows is about 2 inches in diameter and is not as big a deal but you can do that yourself, it's just a bellows and 2 hose clamps. You probably won't take on water with a cracked exhaust bellows but replace it anyway. The driveshaft bellows is a different story and can really get you in trouble if you don't fix it right away.

Blue Thunder

[secondcurve]

Bigdog:

How old is the boat?

[Dave R]

You can run without the exhaust bellows, the risers on the manifolds prevent water from coming back into the engine. I would fix it though. I'd also be 100% certain I knew why it failed before next season too...

[bigdog]

Thanks "all" for the information... I'll have the bellow checked by my mechanic.

I have to concur with "Blue Thunder" , the bellow in question is most likely the "exhaust bellow". It is about 2" in diameter, with hose clamps on each end. Looks simple for a DIY, but then again, sometimes when you get into things, there never appear to be as easy as one first thought.....

Thanks "Dave R", I believe you're correct also in stating that the risers on the manifolds prevent water from coming back into the engine.

I don't know how long this condition has existed, probably all last summer, for all I know. I never noticed this before, then again, I wasn't looking for anything.

Either way, whether I repair DIY, or have fixed by a mechanic, it should be replaced.

Thanks again to everyone who responded, much appreciated !

[Phantom]

Bigdog -- clear your Priv Msg history -- attempted to reply to you and error message read you've exceeded your storage (you can only hold 50 messages max).

LMAO

[Dave R]

Originally Posted by bigdog

Thanks "all" for the information... I'll have the bellow checked by my mechanic.

I have to concur with "Blue Thunder" , the bellow in question is most likely the "exhaust bellow". It is about 2" in diameter, with hose clamps on each end. Looks simple for a DIY, but then again, sometimes when you get into things, there never appear to be as easy as one first thought.....

Thanks "Dave R", I believe you're correct also in stating that the risers on the manifolds prevent water from coming back into the engine.

I don't know how long this condition has existed, probably all last summer, for all I know. I never noticed this before, then again, I wasn't looking for anything.

Either way, whether I repair DIY, or have fixed by a mechanic, it should be replaced.

Thanks again to everyone who responded, much appreciated !

I have never replaced one, my boat has the type that opens up as I trim up, but I understand the inner connection may be difficult to make. Merc makes a special tool called a bellows expander to ease the procedure.

[LIforrelaxin]

Originally Posted by Dave R

but I understand the inner connection may be difficult to make.

I have replaced and exhaust below on an Alpha drive, and yes getting the bellows to slip onto the fitting is a bit fustrating. (round bellows hose oval fitting as I remember) However it is certianly not imposible, even without the tool. Actullay what I found more fustrating was getting the clamps tightened. Didn't have a chance to replace the other 2 boots though, so I have no idea how easy they are, although I would imagine at a minimum it would be a time consuming project.

As an aside note, this is something that should be looked at every year, especially because of the other 2 boots, which as mentioned before can allow your boat to take on water. Once one starts cracking it is probably a good bet to replace all three. However the boat I worked on was not mine and my uncle did seem to want his boat out of the water any longer then I had to have it out in order to make the neccesary repairs.

[Dave R]

Originally Posted by LIforrelaxin

I have replaced and exhaust below on an Alpha drive, and yes getting the bellows to slip onto the fitting is a bit fustrating. (round bellows hose oval fitting as I remember) However it is certianly not imposible, even without the tool. Actullay what I found more fustrating was getting the clamps tightened. Didn't have a chance to replace the other 2 boots though, so I have no idea how easy they are, although I would imagine at a minimum it would be a time consuming project.

As an aside note, this is something that should be looked at every year, especially because of the other 2 boots, which as mentioned before can allow your boat to take on water. Once one starts cracking it is probably a good bet to replace all three. However the boat I worked on was not mine and my uncle did seem to want his boat out of the water any longer then I had to have it out in order to make the neccesary repairs.

I'll be doing the U-joint and shifter bellows on mine next Spring. Looks like a pretty big project that could have been made easier if Mercruiser had used a little more foresight. When you take the drive off ( a ten minute job on a Bravo 3), the U-joint bellows are "right there" in front of you, but according to the service manual, there's still lots of work to do to; bellows replacement calls for "major disassembly". I also plan to tackle the steering play mine has, at the same time, before it gets bad.

[TomC]

Originally Posted by Dave R

I'll be doing the U-joint and shifter bellows on mine next Spring. Looks like a pretty big project that could have been made easier if Mercruiser had used a little more foresight. When you take the drive off ( a ten minute job on a Bravo 3), the U-joint bellows are "right there" in front of you, but according to the service manual, there's still lots of work to do to; bellows replacement calls for "major disassembly". I also plan to tackle the steering play mine has, at the same time, before it gets bad.

For $180-$225, it is worth it to have a mechanic do it. I imagine a shade-tree DIYer will take 10x that amount of time to do it...