Bravo 3 changed ratio and now its blown a yoke seal
07-28-2018, 03:27 PM
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Bravo 3 changed ratio and now its blown a yoke seal
Hoping I can get some professional advice here for a fault on my 2015 Bravo 3 drive, basically a previous owner of the boat had a new drive fitted but they fitted the wrong ratio for the boat, they fitted a new 2.2 ratio, when it should have been 2.00
I found I could change just the upper unit gears to convert it to a 2.00 ratio drive which I did and had my marine mechanic strip and reassemble with the new gears.
Drive was refitted and it all was well, however I noticed pretty much straight away that I was losing drive oil in the reservoir, no oil in the water but after a few trips out I noticed drive oil was coming through the transom via the bellows. So I immediately suspected the yoke seal, drive removed, bellows were full of oil.
A pressure test on the drive didn't show any leaks??? but it was obvious it was leaking via the yoke seal.
So this is my question, why the hell after changing my gearing has my drive just decided to **** it self, new genuine seals were used, everything followed in the merc manual, no over heating, have I missed something here or is it just bad luck? My engineer is stumped because on strip, everything was perfect, gears were running great and still set to everything he set in manual, no signs of overheating, no damage to the seals.
He has just bought new seals and rebuilt it but we are at a loss as to why it leaked in the first place.
Can anyone give me any ideas?
I found I could change just the upper unit gears to convert it to a 2.00 ratio drive which I did and had my marine mechanic strip and reassemble with the new gears.
Drive was refitted and it all was well, however I noticed pretty much straight away that I was losing drive oil in the reservoir, no oil in the water but after a few trips out I noticed drive oil was coming through the transom via the bellows. So I immediately suspected the yoke seal, drive removed, bellows were full of oil.
A pressure test on the drive didn't show any leaks??? but it was obvious it was leaking via the yoke seal.
So this is my question, why the hell after changing my gearing has my drive just decided to **** it self, new genuine seals were used, everything followed in the merc manual, no over heating, have I missed something here or is it just bad luck? My engineer is stumped because on strip, everything was perfect, gears were running great and still set to everything he set in manual, no signs of overheating, no damage to the seals.
He has just bought new seals and rebuilt it but we are at a loss as to why it leaked in the first place.
Can anyone give me any ideas?
07-28-2018, 03:33 PM
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also this time since reassembly, I noticed oil had overflowed out of the bottle on test through the cap, I was doing short runs so 100% no chance for the drive to even get hot, and my drive sits very low in the water on my boat so its well cooled by the water, overflowing oil is making me think excess drive pressure, which then makes me think a possible explanation of why it popped a yoke seal.
Wish I never bloody changed the gears its just turned into a bloody head ache!
Wish I never bloody changed the gears its just turned into a bloody head ache!
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