Oil blow out
 

I have a pair of handed Mercury Bravo 1 drives turning outboard using Mercury High Performance Gear Oil ( Green ) in colour

I have external aftermarket reservoirs from Harding Marine which are now vented and drive showers which take their water from the traditional water pickup point on the outdrive with the engine cooling taken from transom mounted pickups.

Both drives are fitted with Harding Marine shower caps paired to SBC 383 motor with around 450 HP Cam`d for 5800 RPM

The clockwise drive is perfect whereas the counter- clockwise drive blows all of it`s oil out of the reservoir at prolonged hi- speed through the vent. Prior to venting the reservoirs the oil pressure from the drive blew the `O` ring seals out from the bottles.

Anyone have any ideas what is the cause of this problem please and better still how to resolve the problem.

Many thanks

Kalaazar

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I assume you mean clockwise propeller rotation drive does not do this, this drive is loading the lower gear when turning the prop. The left hand prop rotation drive loads the upper gear to drive the prop. There would be better heat transfer to the case than to the upper cap. I would make sure you have cooling water to the top cap. Since you are using hull mounted water pickup, you might need to drill and tap the upper case and have water flow through the the drive.

Thank you, yes it is the anti clock wise drive which is pushing out the oil.
The drive showers are feed from the standard Bravo 1 lower unit water inlet solely feeding the drive showers.
We have also mounted the feed pipe to the shower cap through the upper side of the top gear case so that we have the drive full of water and vented to the shower cap.
And still it is not enough.
Kalaazar

The lube bottle has a one way valve in the cap. The cap valve allows air in but not out. If the valve is not working correctly and heat builds up it will blow out

Try swapping bottle caps or running without cap on problem bottle. If more comes out with it off then it is drive related. Next I would swap drives to see if problem follows the drive.

Is the water going through the drive dumping anywhere else besides into the drive shower?????

If not, that is a lot of water building pressure into a small hose for the shower. The water will not flow through the drive as it should.

Is this a recent or new issue????

Hi Guys,
Thank you for all of your comments. Because the caps as you say are fitted with a one valve we put a vent line in the top of the bottle to stop it blowing out the
`O` rings.
The problem started at the end of last year when we fitted the new engines and because the clockwise drive is not a problem I re fitted larger hoses to both drive to increase the water flow thinking that would solve the issue, but no.
However it has now occurred to me that the normal Bravo1 drive outlet pipe to the raw pump may have lost it`s blank cap on the Port side and the inlet water is simple taking the least line of resistance of in the intake and out of the outlet bypassing the drive shower feed entirely.
I will lift the boat tomorrow and take a look.
Kalaazar

http://www.offshoreonly.com/forums/d...rflow-oil.html

my post # 11 and some others explain the possibilities here.

Great thank you, appreciated.

I also would try Royal Purple 75-90 max gear synthetic. I use it in any performance application.