Bravo 3 Catastrophic Failure

[alldodge]

Guy on the Formula forum had the Bravo 3 carrier come off while running. From the looks of the drive and boat hull it appears to have been well maintained. This is a 2008 37 PC with twin 502 weighting in around 18.5 K. Owner stated

Each year the Formula Merc Tech removes the out drive, checks alignment, changes gear lube, lubes shaft, pulls inspection plates, pressure checks the out drive, pulls the props and greases the shaft. The last time this was done was 10 1/2 months ago.

So the big question is has anyone ever seen or heard of this happening on a B3?

 

[tpenfield]

I saw that thread over on OSO . . Or maybe it was the owners forum . . . I think there is more to it. What the OP described was hard to believe.

 

[alldodge]

I saw that thread over on OSO . . Or maybe it was the owners forum . . . I think there is more to it. What the OP described was hard to believe.

I'm right there with you, just trying to see if there is anything is out there with even similar issues. Heck the prop is turning counter clockwise, the carrier bearing is turning counter clockwise, just how in the heck can it loosen up. Don't think we will ever know, but my gut tells me there was another kind of failure and the mechanic/dealer is throwing out smoke and mirrors so no one will look to close.

If you look at the pics up close I see damage on the carrier threads and outside of it, but the housing not so much. If it was starting to loosen up my guess is this was happening for some time and could have been caught but wasn't

Honestly I would like someone to come along and say yes, this happens all the time with some backup. Hate when folks get taken for a ride

 

[GA_Boater]

Do y'all have a link to the thread(s) over there. Not that I like to refer to other forums, but a lower puking the carrier like that just doesn't sound plausible, far from it. I'm curious.

 

[alldodge]

Do y'all have a link to the thread(s) over there. Not that I like to refer to other forums, but a lower puking the carrier like that just doesn't sound plausible, far from it. I'm curious.

The OSO thread was started by me and has the same info has here other then another question about Konradmarine drives

http://www.formulaboatsforum.com/VB...c-drive-failure-merc-defect&p=58730#post58730

 

[tpenfield]

Do y'all have a link to the thread(s) over there. Not that I like to refer to other forums, but a lower puking the carrier like that just doesn't sound plausible, far from it. I'm curious.

It was on the owners forum . . . here is the link.

http://www.formulaboatsforum.com/VB...ravo-3-catastrophic-drive-failure-merc-defect

When I first read the initial post the BS Alarm in the back of my brain went off big time . . .

The Poster (OP) states the prop spins opposite to the carrier threading (wrong) . . . It is reverse thread because the outer shaft spins counter-clockwise, so any friction should tighten it not loosen it.

OP states the prop wore into the carrier and finally the seals causing the oil to leak out rapidly. . . It is a double seal so it would take a fair amount of grinding by the prop to cause the oil leakage that was stated. There would have been a noticeable vibration that seemed to have gone ignored.

The OP then states that the low oil alarm sounded, at which time he noticed the gear oil reservoir was empty (because the seals had been compromised by the prop interference). . . Well this amount of oil would have created quite a slick which also seems to have gone unnoticed, even when the OP stopped the boat to check things and re-fill the oil.

The OP then states that he filled and refilled the oil reservoir as it kept emptying. . . . Again there would have been a massive oil slick behind the boat which would be hard to go unnoticed while checking and re-filling.

The OP apparently continued to run the engine in this condition which subsequently resulted in the upper gears destroying themselves.

Somehow this is all Mercruisers fault? So, none of this makes sense . . . I wonder what really happened ???

 

[alldodge]

Guess I'm more to lean toward an nieve boater which doesn't work, loves his dealer, and just cannot fathom his trusted dealer would do anything else then tell him the truth. So my opinion is his dealer has not been doing everything the owner has been paying for. They figured he will never know he was being played.

Then water was getting into the drive and now he had a failure. The dealer is now trying to CYA so he doesn't have to pay the freight.

Don't know where he is located but my thought is the ocean. Even if he is in a lake, don't know if he would see a slick unless he was looking close, and he is not a mechanical type. Also the lube would flow out real slow, it is a very small tube.

Still leaning toward trying to give the guy the benefit of the doubt.

 

[Fun Times]

I personally don't recall seeing something like this happen in the past but that don't necessarily mean it hasn't ever happen to someone either.....Sounds kind of rare though.

Unfortunately the photos you posted aren't visible here or on OSO and you have to be a member to see the photos on formula boats.

Maybe something went wrong with the front thrust washer and while in reverse gear it unscrewed the carrier or the housing has unseen damage due to maybe not winterizing/getting the water out of the cavity area...Just some guesses is all.

While there was no response, this guy claims it keeps coming loose on him, http://forums.iboats.com/forum/engi...9-bravo-iii-propeller-shaft-carrier-loosening

There could have also been a small defective run during the carriers manufacturing process that went undetected...To bad we don't know the year of the topic above to compare notes.

 

[GA_Boater]

I joined Formula so I could see these two pics. :smile:

I would think while all this was going on, there must been a heck of a racket from the port drive. His mech diagnosed what was wrong in 20 seconds, but no idea why. And he sees this failure often.

Part of the story is missing.

 

[GA_Boater]

Sorry, AD - I never saw your pic of the carrier until after I did that ^^^^

 

[alldodge]

Let me try it this way




Maybe a formula forum thing

 

[GA_Boater]

We have have plenty of pics now. LOL

 

[alldodge]

As always things like this bug me so did more digging and I think I figured out what happened. Basics for process, parts breakdown. Carrier has an o-ring in front of threads. Behind it is the retainer nut (item 41), bearing race then shims



Here is a pic of my B3 housing prior to reassembly. Note the threads and just below it is the housing ridge where the shims sit then bearing race. Threads start above the bearing race



In the original housing it appears to be the bottom part of the carrier bearing. Thinking this because there is just about 1/4 remaning



To back assumption up is because the bottom of the original carrier appears to be gone



The one thing that still concerns me is the edge of the piece of the carrier (if it is a piece of carrier) appears a fairly smooth break. Either that or the housing was not made correctly. If either is true then it would be a manufactures defect

Thoughts?

Forgot here is a new carrier showing the threads

 

[tpenfield]

I think it is too hard to determine from the picture. If the OP of that thread wanted to post some better pictures, then maybe we could tell with greater certainty. A thought I had is that maybe the prop was improperly installed without the stop bushing, which would have allowed it to push into the bearing carrier and do the damage described . . .perhaps even to the extent of causing the bearing carrier to turn counter-clock-wise, tightening the threads to the point at which they stripped and all heck broke loose.

I still see negligence on the operator's part for not reacting to an obvious vibration that the outdrive would have been making while this was all happening, and for continuing to run the outdrive in an obviously damaged state.

 

[thumpar]

I think it is too hard to determine from the picture. If the OP of that thread wanted to post some better pictures, then maybe we could tell with greater certainty. A thought I had is that maybe the prop was improperly installed without the stop bushing, which would have allowed it to push into the bearing carrier and do the damage described . . .perhaps even to the extent of causing the bearing carrier to turn counter-clock-wise, tightening the threads to the point at which they stripped and all heck broke loose.

I still see negligence on the operator's part for not reacting to an obvious vibration that the outdrive would have been making while this was all happening, and for continuing to run the outdrive in an obviously damaged state.

From the looks of it there seems to be wear on the middle of the carrier and what looks to be a crack so the missing bushing would make sense. What ever happened it doesn't look like it was the drives fault but the person that did the work.

 

[alldodge]

From my view the wear in the middle of the carrier came after it started coming apart.

The first prop goes on with the lip inside the housing. Don't know if the prop would even turn if it didn't have the stop bushing. Wouldn't the paint be worn off the outer edge of the housing if that happened?

Something did happen and with only 330 hours its not high. Agree there would be a lot of noise going on so why did he continue, not a clue (open exhaust, stereo, :noidea: ).

 

[JustJason]

That bearing carrier gets torqued to 150 Ft/lbs. It aint coming out on it's own. My guess is somebody was in there at one point and didn't torque it down properly.