Help: Saildrive or Engine

[svAlegria]

Started the engine (Yanmar 3gm30) the other day and noticed a liquid pooling on top of the saildrive. Upon further inspection the (slightly more that a trickle less than a stream) amount of water was coming from the bottom of the bell housing (right by the indention). It dripped/ran both in gear and out of gear. After 10-20 minutes of running I shut it down. After the engine cooled down it occurred to me to check the oil in the saildrive (SD20). After opening the plug I saw that there was no oil in the saildrive. In 3-4 seconds water started coming through the oil opening. I quickly closed the plug. We are in Aruba and we are not sure about the level of expertise in Yanmar engines and/or saildrives.

Now the question...... Is it a engine problem or a saildrive problem? What parts do you think failed? What do I need to fix?

I REALLY appreciate ANY help.
Dan

[Sailmonkey]

Salt water or fresh?
I'll bet you lost a seal on the lower unit, the engine has no water that passes through the gear area, only up through the leg and out with the exh....

[Sailmonkey]

fwiw, if you can get hauled, anyone that can fix an outboard can fix this item.

[svAlegria]

Why was the water first seen at the bottom of the bell housing. How could water escape from there?


I have to order parts and I want to make sure I get any parts needed. It takes 3 weeks here and lots of money.

[Firehoser75]

But, my first guess is that the lower seal (at the prop shaft) has gone and needs replacing. However, there may be other problems that you might not find until you disassemble the drive. If parts are that costly "down there" then maybe you should wait until after you have disassembled the unit to come to a complete determination of what is actually needed. I know this might mean a longer wait on the hard (of a few days), but probably the best idea overall.

Good luck,
Tom

[shakey doug]

Dan, Basically there are 4 ways water can get in to the gear train section in a std length leg .1. btm seal u/s due to wear or a bent output shaft. 2.outer casing w/t integrity breached. 3. lost drain plug or crook seal. 4.inner cooling casing around top anode area corroded thru. water in bell housing would suggest in put seal cactus.

Doug.

[svcattales]

[QUOTE=svAlegria;365146]Why was the water first seen at the bottom of the bell housing. How could water escape from there?

Dan, The saildrive gear case (upper & lower) is supposed to be completely separated from cooling water passage so cooling water shouldn't be leaking into gear area.

From your description, you have water in the upper gear case which is connected to lower gear case (prop shaft area). Your oil/transmission fluid fills both upper and lower gear cases so a water leak will flow from lower to upper gear case. Since the upper gear case has a splined shaft that goes into the bell housing, water is probably filling up the upper gear box and leaking into the bell housing around the splined shaft.

Now where is the water coming in? First dive down and make sure the drain plug is still there. If that's not it, the most likely place for a leak is the water seal around the prop shaft. I've never tried this, but I have an idea on how to isolate the source of the leak. Get a heavy duty plastic bag and put it over the prop and lower portion of the drive leg. Wrap some rubber (preferably neoprene) tightly around the drive leg to make a seal for the bag. Then seal the bag around your rubber seal tightly with some cable ties. After your "leak stopper" is installed, open the fill on the saildrive and see if water flow stops. If flow stops, the problem is your water seal around the prop shaft. You will have to haul the boat, but repair is fairly easy except for flushing all the seawater of the the gear box. If this is you problem, I would also try to pressure check the drive after you put in new water seal on prop shaft. If the water is leaking around the splined shaft, you may also have a bad oil seal around the splined shaft which is allowing water into the bell housing. Normally, the gear box should be slightly pressurized when warmed up and you will hear a "psst" noise when removing the dipstick.

If the flow continues with your bag in place, you may have a bad gasket which separates cooling water from oil passages. If this is the case you will have to haulout and take apart the drive (big job).

Good luck and let us know what happens.

[svAlegria]

Greg,
Great information. Let me try that and I'll get back to you.
Dan