Water in Bellows?

tony1b2000

Active Member
Oct 10, 2007
243
Salem MA
Boat Info
Carver C37
Engines
Mercury Diesel 4.2 TDI, inboards
Hello all,

Had a bit of a grinding sound the last few weeks on the starboard engine. Had a feeling it was a bad gimbal bearing. Was ready to replace today and pulled the drive. Noticed the bellows was full of muddy like liquid. So now I know why the gimbal bearing went bad....
Also, while pulling the boat out of the water, lots of corrosion all around the drive. Had to replace all the trim cylinders.
So how did the water get in there? The bellows look ok, no cracking that I can see.
Last spring, I had the marina pull both drives and they saw NO water in the bellows but the u joints were rusted. Did they not seal the drive correctly?

What I really dont understand is there is NO gasket between the drive and the bellows. So how does it keep the water out and not seeping in through the drive and the bell housing???
Can water be coming from the drive???
20191110_141651.jpg

20191110_141704.jpg
 
No gasket for the B3.

The seal is made when the drive is pushed up against the outer edge of the bellows. They do dry out over time and may not seal as well as they age.

I found a small amount of water in mine 2 years ago. Couldn’t find any rips or tears in the bellows. I installed a new mercruiser bellows and last year, found no water inside. I’ll be removing the drive in the next week or so and we’ll see how well it held up this year.
 
Like Espos said, the drive makes contact with the bellows. I put a layer of grease on the contact area.
 
On the Alphas there is a rubber ring between the steel bellows ring and driveshaft housing. The rubber ring pushes/seals when the bolts are tightened. In addition, I load the grease there as well.
Do the Bravos have the same sealing technique?
 
Thanks Guys. I like the idea of using grease as the seal may dry out over time. Wondering if a certain type of grease is better than other so it wont hurt, deteriorate the rubber ...
 
Thanks Guys. I like the idea of using grease as the seal may dry out over time. Wondering if a certain type of grease is better than other so it wont hurt, deteriorate the rubber ...

I use Yamalube grease for everything.
 
Is that amount of corrosion considered normal in your area for a 9 year old outdrive?
 
No, this is my first year seeing all my zincs gone and my skegs badly pitted when I hauled. 2 trim cylinders destroyed. The dock I am at is only 5 years old with gfi protection. However, there are a few different boats near me this year. Some had cords in the water. Next year, i plan on a mid season haul out to replace all anodes
 
That's horrible. Do you have functioning Mercathode systems on your drives? When replacing the bearing, have a good look at the opposite end of the main bellow. A bad clamp or corrosion on the gimbal housing can be another point of entry for that water.
 

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