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Blown 3 Bravo III Drives in 2 SEASONS!!!

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Old 07-25-2011 | 11:07 AM
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Default Blown 3 Bravo III Drives in 2 SEASONS!!!

Hey Guys - any help here is greatly appreciated.

Yesterday I blew (stripped beyond repair) my 3rd drive in 2 seasons. Luckily they have been under warranty and Mercruiser has been good enough to cover costs, but it is getting ridiculous.

I am the original owner of a 1999 Cobalt 252 with a 496HO. The boat originally came with a 454MAG, but was re-powered 3 seasons ago with the 496HO. The original Bravo III was great with the new motor until my brother found a bed of rocks and it had to be completely replaced (upper & lower). I had a new Bravo III installed and have had problems ever since (the 3 blown drives does NOT include the original one from the accident).

Each time is the same. Works for a few weeks then one day it will lose propulsion while underway and the RPMs jump. The motor revs perfect, but nothing engages. Yesterday's drive had less than 12 hours on it and never ran above 3,000RPM out of fear for the same issue.

Dealer is claiming I need a Bravo III XR. Anybody have thoughts on this?
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Old 07-25-2011 | 03:15 PM
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Merc mates the the Bravo III X with the 496HO in most applications these days. That said, a standard Bravo III should hold up just fine behind an HO in a 252 Cobalt. I've got 300 hours in a similar sized boat with a standard Bravo III with no problems. What is failing on the drives?
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Old 07-25-2011 | 03:55 PM
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twisting/shearing the spline sleeve between upper and lower?
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Old 07-25-2011 | 04:07 PM
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Call John At The Bravoshop. He Has One Ready To Go I Saw.

Bravshop.net Or 402 297 7977
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Old 07-26-2011 | 07:45 AM
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Thanks for the info guys.

The drive shaft bearing in the upper unit is what is failing. Could this be a horsepower issue?

Drive shaft bearings look very similar to wheel bearings. Why would this failure require all new upper & lower unit?
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Old 07-26-2011 | 07:50 AM
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Sounds like the alignment was tweaked in the impact. You need to have everything in the gimble/bell housing gone through and checked, and make sure the engine alignment is dead on.

Have you beeen using the same shop each time, or doing this yourself? Might be time for a new mechanic.
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Old 07-26-2011 | 07:59 AM
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Sydwayz - that has been my claim all along. I have been using the same shop and they have told me the drive won't install if anything is out of alignment.
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Old 07-26-2011 | 08:12 AM
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Do you mean the bearing on the input (u joint) shaft? In what way is it failing? Can you post a photo?
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Old 07-26-2011 | 10:23 AM
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MBam - they said "no the drive shaft bearing in the upper unit". I will try to get pics when they pull it off tomorrow.

Any advise on questions I should be asking?
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Old 07-26-2011 | 01:13 PM
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Something changed after the impact and is either out of alignment or putting some harmonic into the drive. It is not an HP issue.
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