Gear oil in the bilge

[chris j]

I have gear oil in my bilge I changed the lower unit lube near the end of the season. when I was getting the boat ready for this seasion I noticed the small bottle with additionl fluid was low and I found fresh gear lube in the bilge. When I changed the lube I pinched off the tube from the bottom of the bottle filled the lower unit up from the bottem hole replaced the top air vent screw and unpinched the hose and topped of the bottle. I do not see any oil at all on the transum inside or out and the lower unit is not leaking. There is oil under the bottle on the bracket it sits on. any help would be great This is on a bravo 3 with a merc 350 EFI moter in a Crownline 225 the year is 01.

 

[Don S]

Re: Gear oil in the bilge

Pull the outdrive and check the bellows for gear lube.

You do pull the drive at the end of the season to check for leaks or water and oil don't you?????

 

[chris j]

Re: Gear oil in the bilge

I have never pulled a drive, I boat in fresh water and I didnt know I needed to pull it yearly, but Im learning! What do I need to pull the drive? Where can I get instructions and how will I know what is causing the oil in the bilge and what maintanence needs to be done once the drive is off? Thanks for all your help.

 

[MarkSee]

Re: Gear oil in the bilge

Welcome to IBOATS.....a great place to learn.

Here's a link to the service manual #28 that I use for my 2001 Bravo 3; serial number actually shows it was mfg in 2000.
I don't have a file where you can download it but maybe someone else does.
Boatinfo - Mercruiser Service Manual nr. 28 - 1999-2006 - Bravo One, Two, Three & XZ/XR Sterndrives

My B3 actually was losing lube and leaking from the front seal into the bellows and was a couple hundred dollars in parts/tools, a little mechanical ability and some help from my IBOATS mates.

Have a helper around when pulling the drive off and putting back on; it a little heavy.

Mark

 

[chris j]

Re: Gear oil in the bilge

Thanks thats great info, can you use a cherry picker to pull the drive? what tools will I need to buy and what other maintenance should I do wile the drive is off?

 

[mercs4mark]

Re: Gear oil in the bilge

I have gear oil in my bilge I changed the lower unit lube near the end of the season. when I was getting the boat ready for this seasion I noticed the small bottle with additionl fluid was low and I found fresh gear lube in the bilge. When I changed the lube I pinched off the tube from the bottom of the bottle filled the lower unit up from the bottem hole replaced the top air vent screw and unpinched the hose and topped of the bottle. I do not see any oil at all on the transum inside or out and the lower unit is not leaking. There is oil under the bottle on the bracket it sits on. any help would be great This is on a bravo 3 with a merc 350 EFI moter in a Crownline 225 the year is 01.

I know this is the obvious ....but are you sure you didn't cut the hose when you pinched it closed?

 

[04fxdwgi]

Re: Gear oil in the bilge

I know this is the obvious ....but are you sure you didn't cut the hose when you pinched it closed?

"There is oil under the bottle on the bracket it sits on"

Was thinking the same thing. Gear oil only under the bottle / bracket. Bad hose, bad bottle, over filled at one time....

 

[MarkSee]

Re: Gear oil in the bilge

Thanks thats great info, can you use a cherry picker to pull the drive? what tools will I need to buy and what other maintenance should I do wile the drive is off?

The drive needs to slide back off the mounting studs which usually can be done by 1 person it's just manhandling the drive once it's off.

If you google: mercruiser bravo 3 outdrive removal
You'll find a couple videos you can watch and see what's involved to doing the removal. No special tools needed for removal.
I built an outdrive stand that rolls with 2 x 6s that fit around the cavitation plate and slide the drive off onto that then roll it away from the boat.

There is other maintenance items such as checking engine alignment, checking the condition of the gimbal bearing, ujoint bellows, lubing the gimbal bearing to be done with the drive off and you should read through the service manual (link I posted or search for another) that has information on what needs to be done as you'll also need to change the drive gear lube, service the prop shaft periodically, etc.

Mark

 

[airshot]

Re: Gear oil in the bilge

Thanks thats great info, can you use a cherry picker to pull the drive? what tools will I need to buy and what other maintenance should I do wile the drive is off?

All the more reason to have the proper service manual and read it! Welcome aboard, when one of the helpfull people on here connect you to the proper service manual, down load onto your thumbdrive as it will download much quicker, then you will be able to recall any part of the manual you need, I then print those pages I need and put them into a loose leaf note book for quick reference. I have found this much easier than printing hundreds of pages I don't need. I also go thru the printed pages and add notes found on this forum to help the job go easier and smoother. Boat smart and boat safely.......

Airshot

 

[chris j]

Re: Gear oil in the bilge

Ok I got the drive unit off, not to hard at all! There is not any gear oil in the bellows, nothing but grease. So what should I do now to find the source of the gear oil in the bilge? I will put new seals in the drive and grease all the bearings before I put the drive back in. But still need to fix gear oil leak.

 

[Don S]

Re: Gear oil in the bilge

Well if the bellows is dry, you have a leak in the engine compartment somewhere.
The leak has to be in the reservoir or the hose and fittings going to it.

 

[artificialreef]

Re: Gear oil in the bilge

Might as well do that impellar since you have the drive off now. Dont forget to pressure check it.

 

[chris j]

Re: Gear oil in the bilge

where is the impeller located is it in the lower portion of the drive as it is on an outboard. I thought the water pump was on the block as it is in a car?

 

[04fxdwgi]

Re: Gear oil in the bilge

where is the impeller located is it in the lower portion of the drive as it is on an outboard. I thought the water pump was on the block as it is in a car?

You stated a Bravo 3. The raw water pump is bolted to the side of the engine, belt driven off the front of then engine. Much easier to get to than an Alpha (between the lower and upper drive housings).

Find the belt driven accessory with the two 1 1/4" hoses attached to it. That's your raw water pump. The "automotive pump on the front of the engine" is the circulating pump. You have both.

Better yet, download the manual and read what you have before putting any wrenches to it.

 

[chris j]

Re: Gear oil in the bilge

should there be a gasket on the cap? I have tested the system by disconecting the tube from the bottom of the bottle and using a brake bleeder vacuum pump and it held 15 until I released the vacuum. There is a red rubber tab on top of the bottle but no gasket of any kind in the cap to seal it to the bottle

 

[04fxdwgi]

Re: Gear oil in the bilge

should there be a gasket on the cap? I have tested the system by disconecting the tube from the bottom of the bottle and using a brake bleeder vacuum pump and it held 15 until I released the vacuum. There is a red rubber tab on top of the bottle but no gasket of any kind in the cap to seal it to the bottle

The bottle is designed to hold a positive pressure when the drive heats up and the oil expands. That red thingie is a vacuum breaker to allow air into the bottle when the drive cools, goes into a negative and tries to suck oil back into the drive, if needed. If drive were allowed to be under a negative pressure, it could suck water in past the seals. And yes, there should be a gasket on the cover.

 

[chris j]

Re: Gear oil in the bilge

I cant find a gasket at the dealer is it a rubber gasket? If so I may be able to make one or find an O ring at Lowes, what do think

 

[chris j]

Re: Gear oil in the bilge

Fixed I got the drive back on and took the boat out today and it work great no leaks of any kind THANK you all for your help