Water inside drive shaft bellows

Coz

Active Member
Oct 9, 2018
443
Boat Info
2008 Sundancer 310
Engines
Merc Mag 350 DTS w/Bravo III
Pulled my bravo 3 drives. First time I’ve ever done that so I’ve never seen the inside but I know this is not right. Port side is clean, no rust, looks great. Starboard side pics attached. So, how do you determine source of leak? I did notice some milkyness in drive oil when I drained it.

Last spring I greased the gimbal bearing using the zirk on the outside of the drive. When I pulled off the grease gun, the zirk came out of the drive. Stripped out. I threaded in a larger zirk and it seemed tight, but could that be a source of water?
 

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Pulled my bravo 3 drives. First time I’ve ever done that so I’ve never seen the inside but I know this is not right. Port side is clean, no rust, looks great. Starboard side pics attached. So, how do you determine source of leak? I did notice some milkyness in drive oil when I drained it.

Last spring I greased the gimbal bearing using the zirk on the outside of the drive. When I pulled off the grease gun, the zirk came out of the drive. Stripped out. I threaded in a larger zirk and it seemed tight, but could that be a source of water?
It’s possible. But I’d think that the gimble bearing would show signs of water intrusion, like noise or difficult to turn.

How old are the bellows? Are they 2008 originals?
 
No idea on the bellows. I’ve only had the boat 2 years.
If I replace the u joint bellows, guess I should do em all. The kits come with gimbal bearing, water hose, etc. Do you normally replace it all?

What special tools do I need? Service manual shows several.
 
Yes, typically you do it all while things are apart.

U joint bellows
Shift cable bellows - new cable also
Exhaust bellows or tube
Trim sender / limit switches
Water hose
Gear lube hose
Gimbal bearing - if it is the old type you can grease it can last forever unless it runs dry of grease or gets wet. I just check mine, it is original and still quiet and smooth. The new sealed type, change. In your case you are already doing one, I would do both.

Tools:
Hinge pin removal tool.
Bellows retainer ring install tool
Alignment tool
Exhaust bellows install tool, unless you have an exhaust tube.
Bearing puller for gimbal bearing
Bellows adhesive

I’ve done the bellows on my Alpha, but never a Bravo III, other than the shift cable being different and it being heavier and the job is basically the same. You can find the tools online and in sets. The bearing puller I think can be rented from Autozone. Not the easiest job, but doable and even after buying the tools a big savings over paying to have it done.
 
I have the older style gimbal bearing and it seems ok, no play and smooth. Job doesn't look too hard, but all these special tools is crazy. What about the water hose insert tool? Can that be done some other way or do I need the tool?
Does the shift cable have to be removed all the way to the engine? Are you just pulling the wire part out of the sheath or do you need a whole new cable? I have DTS and haven't looked inside engine bay yet to see how it connects.
 
Just when you do change shift cable and bellows... Do not go after market... Quick Silver... The other cables you won't be able to adjust right and the other bellows leak... They don't seat right.. I would bring it in to do this type of job.. Just tell them you don't want aftermaket parts... This really ain't a do it your self job... Its a pain in the ass
 
You won't need the tool for the Bravo bellows. The tool for the water hose insert doesn't cost much but if the hose looks good I would leave it alone. Access behind the engine is tight.
 
I would highly recommend that you get the bravo drive with rusted ujoints "Pressure Tested" while you have it off. Very inexpensive to do. The u joint seal (inside the drive) is designed to keep the Gear oil from coming out of the drive, not so much to prevent water going into the drive.
I had water in my bellows last year. Had new bellows installed ( the works).
But when I pulled my drive at this end of season, my bellows were full of gear lube!. When pressure tested, it showed the u joint seal had failed and needed to be replaced.

There are a lot of you tube videos on changing out the bellows, etc.. I suggest watching a few to see how comfortable you are doing the task yourself.
Bellows should last about 5 years. If unsure how old yours are, its worth doing them rather than getting hauled out in the middle of the summer!!!
 
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Whether or not you can do this yourself, that’s up to you. If you’re the type that doesn’t do your own oil changes, brakes etc. then this may be too much of a project.

I did mine 2 years ago. Watched a bunch of YouTube videos and researched the procedures. I also made the tool for crimping the shift cable bellows. It involves an old pair of pliers and welding a 1/2” nut to the jaws and then cutting the nut in half.
 
Just when you do change shift cable and bellows... Do not go after market... Quick Silver... The other cables you won't be able to adjust right and the other bellows leak... They don't seat right.. I would bring it in to do this type of job.. Just tell them you don't want aftermaket parts... This really ain't a do it your self job... Its a pain in the ass

Are you saying to use Quick Silver or not to?
Whether or not you can do this yourself, that’s up to you. If you’re the type that doesn’t do your own oil changes, brakes etc. then this may be too much of a project.

I did mine 2 years ago. Watched a bunch of YouTube videos and researched the procedures. I also made the tool for crimping the shift cable bellows. It involves an old pair of pliers and welding a 1/2” nut to the jaws and then cutting the nut in half.

I saw that in the service manual and thought wtf!
Just ordered a new service manual, hoping there’s a new way
 
I re-examined things today and the bearing on the bad drive is the newer sealed style. So I would assume the bellows would have been replaced at the same time. I can’t find anything wrong with the bellows. I even turned all the lights off and shined a light inside the bellows looking for light leaks. the bearing is smooth and no play.

I’m wondering if the water isn’t coming in through the grease zirk that stripped out. All the new bearings are sealed right? I think I will drill and tap that and put in a brass plug or SS if I can find one.
 
I re-examined things today and the bearing on the bad drive is the newer sealed style. So I would assume the bellows would have been replaced at the same time. I can’t find anything wrong with the bellows. I even turned all the lights off and shined a light inside the bellows looking for light leaks. the bearing is smooth and no play.

I’m wondering if the water isn’t coming in through the grease zirk that stripped out. All the new bearings are sealed right? I think I will drill and tap that and put in a brass plug or SS if I can find one.

You may be right about the fitting, but more likely you are looking at moisture created via condensation. The driveshaft spins as long as the engine is running and that creates airflow. The whole thing is mounted on the backend of the engine in a damp enclosed space, so it’s hot moist air being circulated into a rubber tube surrounded by water that is cold. That creates condensation on the inside of the bellows.
 
FYI, a replacement (OEM) Gimbal bearing comes with a setscrew to fill the hole were the Zirk fitting is. Possible someone forgot to install it???
Personally, I don't like the way the outdrive is simply sealed against the metal ring and bellows. I put a bead of silicone on the ring before I put my drive back for added protection . Others will suggest grease or nothing at all.
Bearing.jpg
 
Are you saying to use Quick Silver or not to?


I saw that in the service manual and thought wtf!
Just ordered a new service manual, hoping there’s a new way
If that is all that’s holding you back from doing it yourself, I’ll send you the crimping tool that I made.
 
If that is all that’s holding you back from doing it yourself, I’ll send you the crimping tool that I made.

just thought it was funny they have a special tool for everything but in this case you’re supposed to weld a nut to a pliers, then cut nut in half, then drill the threads out. Why isn’t there a regular hose clamp there anyhow?
 
So which kit is the best to get, the quicksilver or merc? See my post #12 above.
Also, is there any way to replace the U joint bellows without removing the bell housing? The exhaust tube can be removed without removing the bell housing, wondering if that would allow access to the u joint bellows.
 
So which kit is the best to get, the quicksilver or merc? See my post #12 above.
Also, is there any way to replace the U joint bellows without removing the bell housing? The exhaust tube can be removed without removing the bell housing, wondering if that would allow access to the u joint bellows.
Coz,

Quicksilver "IS" Mercury. The ONLY difference is the packaging. Let me explain why. Only an Mercury authorized dealer can have the name "Mercury" listed on the packaging. All NON Merc dealers will have Quicksilver labels on the packaging. Mercury was smart to do this in that they wanted to expand selling their products to many more places.

If you don't believe me, call Mercury direct at 920-929-5200. They will ALSO be able to answer your question on how much pressure for a pressure test. Great support! Have you engine serial # on hand!!!

That said, don't confuse Quicksilver with brands like Sierra. Sierra is NOT an OEM Mercury product.

Re the u joint bellows. Very challenging to replace without removing the bell housing. Especially when trying to glue it on and holding it in place.
Absolutely worth taking the bell housing off. You tube is a good source to see the process.
 

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