Gear lube in the bilge

[rgreenwell8962]

Yesterday before heading out on a 3 hour trip I checked all the fluids and noticed the drive reservoir was on the add line (cold engine). I filled it to the full line. After a full day running I looked and there was gear lube spilled in the bilge and the level was back at the fill line. There was no sheen in the water so I assumed it was coming from the reservoir. Could it have been that I filled it while cold and then when it heated up it spilled out? I am on a 5 day run and a bit concerned. The drive was serviced recently and has about 5 hours post service.
Thoughts??

Thank you.

PS... Seapuppy was a Canadian Whiskey fan, so I toasted him on the water near his home port today. Godspeed Steve. My first thought upon seeing the lube in my bilge was to ring him on his cell phone. I miss him!!!

[pascavone]

if the drive was serviced, you must have air bubbles trapped in the drive, and they are working themselves free.

Simple air displacement, with the drive oil working down into the drive.

A little oil in in the bilge can come from the breather hole in the cap of the reservoir, which lets the air out.

The hot oil expanses and will push back a bit under way.

The drive alarm will ring if you have a problem....

[rgreenwell8962]

Thanks. I was thinking that may be the deal. I had a slight amount of water in the bilge from changing out the fresh water pump so it looks like a lot more oil than there actually may be. So, would you top it off again?

[ss3964spd]

Don't top off this time. Fill it so it's between the two lines and then run it and see how it does.

Dan

[rgreenwell8962]

So I didnt top off and got underway back home. Within 30 minutes the sound changed, a bit lower in tune, so I stopped and opened the hatch. The drive reservoir was darn near full! Nothing had come out of the vent cap yet though. I opened the cap and took it off to look at the fluid and it dis not appear to be milky, just a bit bubbly. Put the cap on and. Ontinued on my way home checking the level every now and the . It never overflowed or got to the full mark again for the remaining 3 hour run at cruising speed. What the heck???

[pascavone]

if it's work'in, don't fix it!

[timer]

rgreenwell8962 How is it working now. Im having the same ploblem with one of my bravo 2 drives. Again i had the drives serviced They pressure tested & vacume tested a-ok. they were filled prior to install on the boat. If i have the reservoir filled to the full mark it will quickly puke out the oil to the fill mark. About 100 ml? If i do not top up it will go down even further but only about 1/2 that amount. Again clean oil but bubbly/frothy. My Mechanic says he has never seen this before. The other drive is fine. I will take the boat out again & see if it goes down even further? Over 7 hrs of use both poking along as well as on step i have probably went thru anout 1/2 a qt. A bit at a time. im starting to worry as i would have expected this to have sorted out by now. Maybe a longer trip is required?? any tips
thanks
Timer

[shrew]

This sound like air in the line. When i drain and fill my drive, I only pump it from the bottom up to the Fill line on the resevoir. It almost always takes care of the rest. I suspect the volume going up and then down is actually the air bubble. As it rises, it displaces the same volume of oil relative to the size of the air bubble UP into the resevoir, then it drops the level back down again. If there is too much in the resevoir, this gets displaced. then the oil left in resevoir goes back down again. Only now it is lower because a bunch got displaced.

This is why you don't initially fill it past the Fill Line. Let it do this until the bubbles work out and then top it off afterwards. Otherwise you get a bilge full of gear lube.

[timer]

I will sit tight for a while, watching as i go. Thanks
Timer

[timer]

Talked to a marine mechanic while buying parts last night. He thought at some point Mercruiser was having problems with those caps on the reservoirs not venting properly causing the same issues. He suggested changing caps , one reservoir to another & see what happens. What do you know. The problem followed the cap to the other reservoir. & the reservoir giving me all the grief was a-ok. It sounds like the cap. Is it really important that the cap has the little orange flapper. If it was removed air could mover freely in & out of the reservoir with no build up of pressure. It would mean the potential for dirt to get into the tank, but im thinking the engine bay on a boat is a pretty clean enviroment anyway.
Your thoughts.
Thanks
Timer

[ss3964spd]

Well I'll be darned. Fantastic that you were able to get it sorted out.

[mmwjr]

That's a new one to me.

Well that is what the forum is for, we all learn something

[timer]

I Have since talked to the mechanic. I have removed the orange discs. Upon doing so i found the cap working properly was dry. meaning the surface between the cap & disc was dry with no oil. The one failing was wet with oil. So it would seem if it was dry it would work. Fine but this is a lid for an oil tank mounted on a boat that bounces. Its in my opinion that if its dry it would not be for long. thats why i cut the discs off But left the center plug. Therefore the tank only has the small hole to vent as originally designed.
Timer

[pascavone]

my drive oil reservoir will expand up as the oil get hot, and leave a drip of oil right in the middle of the cap.

Perhaps, you are over filled, and after long runs its expanding out.

I'd let it go down to the add line and see if you have a drip.

Also, you just might have engine coupler grease that dripped off the drive, as it should be serviced with a shot of grease every season.

that grease will spin off and go flying onto the steering gears.

[timer]

I was on the right track but wrong. Our family just returned from a 13 day boat cruise & put 26 hrs on the boat. Every time the boat was used a small amount of oil would not come out of both reservoirs. Oil level would continue going down to near the bottom of the reservoir with no end in sight. I was at a marina overnight that was a mercruiser dealer. I had them order 2 new caps for me. They came the following day . I looked the new caps over & noticed one had a flat rubber gasket (like an oil filter) & one did not. Both had same part#. I then looked at mine & found one of mine was missing a gasket as well. The one missing the gasket was originally on the tank giving me trouble. I took the gaset off the other old cap & put it on the new cap without one. Problem solved.. Not a drop. 10 + hrs later. I have since filled the reservoirs to the proper level. a-ok. It seems that Mercruiser is not aware of the problem either.HMMMM
hope it helps. Timer