Drive oil loss?

[Dr. David Fleming]

Ok, three years now my drive oil supply bottle uses about one whisky shot of oil each day. Now there are no leaks from the prop shaft, drain plugs external gasket surfaces. The drive was removed and the engine alignment checked, the u joints lubed and drive coupling greased - no visual loss of drive oil - maybe a small amount slopped out the reservoir cap vent - anyone have similar experience with lubricant loss - its the only fluid I constantly fill?

[Planetwarmer]

Ok, three years now my drive oil supply bottle uses about one whisky shot of oil each day. Now there are no leaks from the prop shaft, drain plugs external gasket surfaces. The drive was removed and the engine alignment checked, the u joints lubed and drive coupling greased - no visual loss of drive oil - maybe a small amount slopped out the reservoir cap vent - anyone have similar experience with lubricant loss - its the only fluid I constantly fill?

Hopefully, this only happens on the days that you drive the boat. That could get expensive!

Maybe your neighbor is stealing it from you a little at a time! It may be time for a locking reservoir cap!

[Tidbart]

I had a similar issue with my bravo. It started after an oil change. I kept having to put an ounce or two every time I went out. No drip, leaks, nothing. Eventually it stopped. Only thing I can think of is trapped air in the drive. And yes, it was filled properly, from the bottom. Drove me crazy for a while.

Bob

[DonziJon]

Just speculating here. I don't know the answer. No one seems to have disappearing oil problems with the old drives that had all the drive oil Captive in the drive. We just don't open the top plug every day to kook at the oil level. The drive is Sealed and as such is not open to the atmosphere. .

These days, the new drives have a remote reservoir that is above the drive and is open to atmosphere. Atmospheric (barametric) pressure changes from hour to hour, day to day. Temperature changes as well....particularly in the engine room.

Just suppose..during operation, the drive oil in the drive is aerated by the gears..causing the oil to expand in volume. It's not under any restraint by a closed/presurized environment so it "wells up" into the resevoir making the resevoir appear to be full. Once the oil cools down and the entrained air percipitates out..the oil level goes down.

So where is that one ounce a day of voluntarily ADDED oil going...? I'm still pondering that.

Maybe just don't look at the oil level every day. If you find the level down one day..Leave It Alone for a few days and see if the level continues to go down..or maybe returns to "Full" level.....for whatever reason.

OK: Time for an adult beverage.

[RedDog]

Mine was doing the same last year. Found it was leaking into the gimbal rubber boot. Had if resealed and then had a leak coming from the cap. Found that hte small o-ring wasn't in its groove. Fixed that the and leak is gone.

[Dr. David Fleming]

Ok, so this is a fairly commonly experienced issue.

1 - I left it alone three years ago and the bottle drained down and set off the engine alarm.

2 - The flush and refill along with the lube and engine alignment was done by Tyler Crockett Marine Racing engines and it is not the first time they had the drive off. I mentioned the oil usage before they took it off and refilled it - they saw nothing wrong and would be glad to charge me to fix it if they did see a repair.

3. - Its been doing this oil usage thing every year for several years and I always add the shot - two years and I am about ready for another quart of oil.

4 - The reservoir is the plastic one with the black screw on cap with what looks like a red rubber vent valve in the top of the cap. There is a small stream of spatter from this cap blown onto the transom every trip. Its mounted on the transom because of the CMI E Top headers.

5. - The only option mentioned that I haven't checked thoroughly is the leakage through the bellows seal - how do I check for this?

6. - Is it possible to vaporize this oil so that it vents as some kind of vapor - have a Latham drive shower on the drive.

Thanks

[mrfixxall]

Ok, so this is a fairly commonly experienced issue.

1 - I left it alone three years ago and the bottle drained down and set off the engine alarm.

2 - The flush and refill along with the lube and engine alignment was done by Tyler Crockett Marine Racing engines and it is not the first time they had the drive off. I mentioned the oil usage before they took it off and refilled it - they saw nothing wrong and would be glad to charge me to fix it if they did see a repair.

3. - Its been doing this oil usage thing every year for several years and I always add the shot - two years and I am about ready for another quart of oil.

4 - The reservoir is the plastic one with the black screw on cap with what looks like a red rubber vent valve in the top of the cap. There is a small stream of spatter from this cap blown onto the transom every trip. Its mounted on the transom because of the CMI E Top headers.

5. - The only option mentioned that I haven't checked thoroughly is the leakage through the bellows seal - how do I check for this?

6. - Is it possible to vaporize this oil so that it vents as some kind of vapor - have a Latham drive shower on the drive.

Thanks

What could be happening is the reservoir hose going through the transom is leaking then dripping on the coupler then whipping it on to the transom..starboard side next to the water inlet theirs a quick disconnect,in the pic you will see a orange o'ring..replace the quick disconnect and the o'ring...merc had a problem with them cracking then leaking..in order to replace the whole assembly the drive needs to come off in order to get it out..

[Tidbart]

Also, on a side note, try one of these caps to get rid of the annoying cap leaks.

http://shopping.rexmar.com/Merchant2...04&Screen=PROD

http://www.hardin-marine.com/detail~ID~1068.aspx

I put one on the reservoir and one on the trim pump. They work, and add bling.

[jimishooch]

the reservoir cap should have a gasket/o-ring in it. if it doesn't it will leak down the transom. don't ask me how i know............
good luck
jim

[Cuda]

I'd check the cap. I know they make aftermarket caps just for this reason.

One thing is for sure, it's not evaporating.

[RedDog]

If the oil is leaking into the gimbal bellows, you could tell by visual inspection with the drive removed. In mine, it was a gooey mess

[G-MAN]

You need to have your lower unit pressure tested, had same problem with our ski boat, had two leaks, at the shift linkage seal and from the main shaft seal, also would never see any oil leak, was lost when running.

[upnorth]

There is an o-ring between the upper and lower gearcase that could have hardened up and is leaking. It is in the same area as the exhaust cavities so you would not necessary see it. Just a thought.

[In the red]

My 06 Bravos do the same thing. Both go down the same amount. Maybe an ounce every two to three days I use the boat. Caps are not leaking. The drive shower sites say that hot drives can cause oil to weep past the seals. I removed both drives, added Latham showers, did pressure and vacuum tests on the drives with no leaks found. Bellows boots were dry. Replaced the o rings and re-installed the drives. Drives are running cooler with the showers, with no chalking on the top caps but the disappearing drive lube issue still remains. Ive just gotten use to adding a couple ounces once a month or so when I am using the boat every weekend.