Bravo 3 Bellows.....

mrgrumpy2

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I recently discovered that the bellows on my Bravo 3 drive wasn't fitted properly and consequently it's been full of water for the past 2 years. The engineer has confirmed that the Gimble and UJ are wasted....Both are being replaced as well as any necessary seals. My worry now is whether two years of submersion could have caused any other long term damage to the leg. The major worry however is whether it's possible that any of the water could have travelled along the bellow and found its way into the engine. Should I be overly concerned and commission some kind of mechanical inspection.....Thanks in advance.
 

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Check out the starter motor to see if it got wet (if large amounts of water went that way, you would have noticed the bilge filling up).

Also check out the bearing/seal that the U/J is connected to at the outdrive end.
 

spannerman

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We have experienced this many times, I have four collapsed drives in the shop right now all from brand new boats! the failure is because the boat builder installed the drives incorrectly so its not Mercruisers fault.
The gimbal bearing will need replacing and yes some water could have found its way past the shaft into the engine room but it shouldn't affect the engine apart from some localised rust maybe, as the water will fall down the transom shield into the bilge.
However your main concern should be the drive as the water rusts the shaft where it goes into the upper gear housing and this rips up the seal which can allow seawater into the drive with dire consequences as the clutches and bearings will be damaged, I'd want the top off the drive to inspect the gears and bearings.
I am suprised it lasted two years as the UJ's cause vibration and horrible noises when they rust up.
 

Elessar

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i have a brand new set of UJs for bravo in my shed. Bought when I thought it was just the drive shaft broken but all the internals were shot too so I bought a new drive. PM me if your UJ is shot you can have them for 1/2 whatever the dealer wants.
 

paultallett

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Sorry to hijack Mr Grumpy, but my question is kind of related....possibly!!!

My Bravo drive has always worked great, no odd noises, always maintained as per instructions by dealer.

Last Sunday we was locking in to Hythe when I was asked to turn and wait by lock control. Engine revs was about 1800, I put the helm hard over without throttling back and noticed a rumbling noise. I've never put full lock on at these revs before.

Once in the marina, I had a good check, full lock and at tick over revs produced no noises or odd viberations. Next day coming back, again had no more rumblings, but again I only applied normal tickover revs when using full lock whilst locking or berthing.

Is this normal bravo stuff at these kind of revs or should I be worring about my UJ??? /forums/images/graemlins/blush.gif

Regards Paul
 

mrgrumpy2

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Ellesar...Thanks for the offer but the parts are already being reassembled.
Spannerman...The boat has had minimal use in the past couple of years and not been used in the past 8 months. The oil in the leg has also been checked and there is no sign of water so I'm assuming that the seal you mention is still holding. It will still be replaced as a precaution.....Thanks guys
 

spannerman

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Put the gear in free and turn to full lock and bring the revs slowly up to the 1800 rpm you mentioned, if you have a grumbling sound its probably the gimbal bearing that needs replacing, and the U/J's can be checked at the same time.
 

FirstLady

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Hi, I had a gimbal bearing failure in my SX drive a couple of seasons ago. It started as a quiet rumbling when I had the helm on either lock- didnt really notice it at first. Eventually it was quite loud & could hear it all the time.

I have experienced some grumblings before with full lock turns- I think this can just be caused by the props fighting against each other- a bit like having no differential on a car in a turn, so it may have been this you experienced. I would keep monitoring the noise and see if it returns on a more permanent basis before worrying too much.
 

paultallett

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Thanks Spannerman. Next time we go out I'll give it a try and see what happens. I just didn't know if the extra noise was normal at higher revs with full lock on seeing as I've never done this before!!! I'm probebley just getting paranoid!!! /forums/images/graemlins/cool.gif
 

paultallett

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Isn't this forum great..... I never realised when we go boating we all are having the same problems, I always think it's just me!!! It's good to know everybody else is always saying 'Did you hear something then' or 'Not another bloody grand again'!!! /forums/images/graemlins/laugh.gif
 
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