Accidently put motor oil in the lower unit

MDboater

So in my rush to finish winterizing last night I pumped motor oil into my lower unit (Bravo 3).  I had pumped a half quart of gear lube then switched bottles and accidently grabbed a motor oil bottle.  After pumping 3/4 of a quart of motor oil I discovered my mistake.  So I drained the oil from the lower unit.  Pumped in the remaining 1/2 quart of lower unit oil.  I then let that drain in attempt to flush any residual motor oil.  Then I put in 2 quarts of gear lube.  I am still a quart of gear lube short and plan to fill soon.  Is it likely that this will damage anything?  Is there anything else that I should do?

Thanks,
MDboater

Handymans342

You should be fine. 

Michael T

@Alswagg would be the guy to talk with about this and I would call the Mercury customer help line too. A neighbour did this years ago. I believe the marina he drove it to afterward with his boat on his trailer drained his drive (it was a Bravo 1), put a degreasing fluid through it, filled it with gear lube and drained it, filled it with gear lube again and ran the engine with "muffs" supplying water at idle speed with the drive in gear (prop off) , then drained that gear lube then re-filled it. Maybe overkill? I bet Al would have seen this before from some customer or other!

MarkB

Holy crap that does seem like overkill, but what do I know.

Handymans342

Really MT?

F1100

It will be fine , the small residue of the engine oil left vs the vast quantity of gear oil will not make a difference

Michael T

Steve, I just relayed what my next door neighbour had done at a marina's suggestion about 10 years ago. He kept the drive for three or more years and never had a problem, so obviously that plan worked. Overkill? Who the **** knows? It worked.

As for other solutions, I trust Al's judgement.

In my case I have two new Bravo lll X drives. They will be under The Mercury Platinum Protection Program until 2022. If something like this happened I would take no chances and have the dealer get Mercury's solution, in writing, to avoid any future warranty misunderstandings. Even if it weren't under the MPPP "warranty" I'd probably still flush and re-fill the drive at least once, maybe twice.

F1100

why would they not warranty it? how would they know of a few cc of engine oil residue vs the gear oil being in the case if you tried to claim the warranty?

these engines and gearboxes are not space craft you know or even close to being to that level of quality. Small variances in lubricant viscosity caused by a extremely small residue of another lubricant will not effect anything.

If it was a factor then. flushing the gear box is not enough..you should pull it down, and apart and degrease the entire gear box, then reassemble and fill. (only in NASA would we be doing stuff like this)

MDboater

Alswagg said:

You will be fine.   You are using Mercruiser hi performance gear lube at minimum correct?  Full synthetic is much better.   Do not use standard gear oil aka burn down Black Death.  

Thanks!!  I used the Quicksilver 90W high performance gear lube.