Bravo 3 Catastrophic Failure
10-02-2015, 08:05 AM
#1
Bravo 3 Catastrophic Failure
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
So the big question is has anyone ever seen or heard of this happening on a B3?
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.
10-02-2015, 08:34 AM
#2
Also anyone hear of Konrad marine, appear to make a heavier upper for twin props but look like same B3 lower
http://www.konradmarine.com/
http://www.konradmarine.com/
10-02-2015, 01:30 PM
#3
Registered
There is quite a bit on Konrad on the site. TRS to Konrad conversions being the most popular.
10-02-2015, 06:36 PM
#4
Don't know what is happening at this site but I'm not being notified of post.
I'm seeing Konrad as another person building an upper section to mate to the standard B3 lower. Wouldn't mind some clarification of my assumptions.
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. Been done to many to many times and even not to long ago
.
I'm seeing Konrad as another person building an upper section to mate to the standard B3 lower. Wouldn't mind some clarification of my assumptions.
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. Been done to many to many times and even not to long ago
.
10-03-2015, 12:46 PM
#6
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?
A new carrier showing the threads
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?
A new carrier showing the threads
10-05-2015, 08:40 AM
#8
Registered
Don't know what is happening at this site but I'm not being notified of post.
I'm seeing Konrad as another person building an upper section to mate to the standard B3 lower. Wouldn't mind some clarification of my assumptions.
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. Been done to many to many times and even not to long ago.
I'm seeing Konrad as another person building an upper section to mate to the standard B3 lower. Wouldn't mind some clarification of my assumptions.
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. Been done to many to many times and even not to long ago
.
10-05-2015, 04:16 PM
#9
Registered
About ten years ago I talked to an engineer at the Carolina Classic factory in NC. He said they were have 85% failure rates on Bravo 3 in their heavier boats, over 12k lbs. They went exclusively to Volvos.
10-05-2015, 04:56 PM
#10
Appears to still have troubles with notification here.
Agree, same rotation so as it rotates counter clockwise it should try to tighten the nut not loosen.
That's good to know, the poster didn't mention it. I and others figure there is more to the story then what were getting. I posted on iboats also, and those folks don't see how it could happen unless there was a defect in something. That said if it was a big problem there would be more folks posting about the issue. This is the first I and others have heard of it
Don't know for sure but Carolina 32 (23K) went to diesels, and shorter then that is using twin Yamaha outboards
Be nice to hear if BUP knows any info on this
Also note the carrier assembly threads in left hand thread, same direction as rear prop rotation. I have seen one start to work loose on a friends boat.
Konrads require a transmission. They are not cone clutch drives.
About ten years ago I talked to an engineer at the Carolina Classic factory in NC. He said they were have 85% failure rates on Bravo 3 in their heavier boats, over 12k lbs. They went exclusively to Volvos.
Be nice to hear if BUP knows any info on this
