Cleaning out Bravo 3 lower unit

boataholic

We are having the most expensive boat year of all times!  As I mentioned in other posts, I had the lower units of my bravo 3s replaced because of corrosion to the cases.  After about 6 hours of operation, one of the upper units completely stripped one of the gears.  It was during this repair, I was informed that I need the new gimbal ring and shaft I mentioned in a post last week.  I have two questions.  #1 Was this just bad luck or could the marina mechanic or new lower unit have caused the gear problem?  #2 How am I going to get the metal shavings out of the new lower unit from the gear failure in the upper?  Please help! 

MarkB

I can't answer your last question, but how old is your drive? It's highly probable that you've reached the lifespan of the upper and lower drive. Gimbal bearing is probably just preventative maintenance, as it will go in the next couple of years, so rather do it now that the drive is off.

boataholic

You're probably right.  Just seems odd that the upper unit failure occurred so close to when the lower unit was replaced.  Gimbal bearing was replaced a couple of years ago.  The gimbal ring needs replacing now.  Mechanic says he must pull the engine to do the repair.

Black_Diamond

The lower unit of the B--III is far more complicated than the upper. I deal with industrial gearboxes and bearings every day. Here is the truth:  you will never get the lower unit flushed out of debris. Even if you could, the microscopic damage done to the bearings and gear teeth are not reversable. Hate to pass on that news, but you'll trash a new upper plus the lower if you don't overhaul/replace it. 

Michael T

@BD. Agree, with failure of the scope @DI has shown its a broken play. @DI was money smart to replace the entire drive IMO, for exactly the reasons you stated.

Dream_Inn

I would, at a minimum, have the entire drive overhauled (as Al mentioned).  I went with full replacement because mine had some casing damage inside the upper as well.  To me, the cost would've been at least half of what it would be for new, so I went with new.  To me, that gives me a bit of warranty, and peace of mind that it is new.

boataholic

I appreciate the insights.  I certainly wish I had a mulligan on this one.  I probably took poor advice but it seemed reasonable at the time.  I just can not afford to scrap an expensive lower unit with less than 5 hours on it. 

boataholic

That makes me feel better!  Do you or anyone else have any experience with re-man drives (upper, lower, or complete) from OBR?  I believe they wholesale to Merc After Market, Crowley Marine, among others.