Hey guys maybe someone can help me out before I go removing the gearbox. I changed my oil today and after running the engine noticed that I have a leak right under the bell housing. The leak was milky brown which probably means it's mixed with water. Thought it was the engine oil. Checked the oil in the motor and its nice and clean. Checked the oil in the transmission and it is very diluted and milky light brown/beige color. I pumped all of it out, and filled some more oil and will run it and drain it again to try and get rid of the water. My only question is how the water foundits way into the transmission and where could it be leaking from? It seems to be draining out of the hole in between the two bottom bolts that hold the mounting flange onto the motor bellhousing. Any ideas?
Transmission problems yanmar 2gm20f with km2a
- Thread starter Fashin
- Start date
Is there a cooling system leak? Where from is the water originating, there should not be water in the bell housing? A recent accidental flooding, a bad packing gland, pressure washing the cockpit, rain leaks ? When was the last time you checked the transmission oil? Over a couple of years water vapor, condensation and oil breakdown can cause a milky emulsion. I would do what you are doing. Flush the transmission with new oil a couple of times, clean the transmission, bellhousing, and the bottom underneath. Check the transmission housing for any cracks. Start using the boat and after every use examine the area, the transmission oil level and condition. The transmission could have a faulty oil seal, but besides an oil leak the big question is the water. Besides trying to establish an ongoing transmission oil leak leak try to figure out how fast does the level go down or the emulsion kicks in. If the oil fouls in a few weeks then you will have to pull the transmission, but if it lasts for 6 months or more Just keep changing the oil and try to eliminate any source of water to the area.
Thanks bud, I just recently bought the boat and was doing routine maintenance on it and was waiting to do the transmission oil after the regular oil change. In the middle of me changing the oil I realised that one of my batteries was dead beyond belief and was over heating so got side tracked into dealing with that and then coming back to the transmission. It seems that the oil only leaks when the motor is on, and not when it is off. Its also very strange but the motor has this dry red stuff all over the bottom that seems slightly caked on. Makes me question if it is dried up coolant, or if it is possible that the po used atf in the gearbox... I have no visible coolant leaks and the levels seem pretty stable. Will check more tomorrow.
The dip stick/fill cap has a vent hole in it. Could it be that water was leaked or sprayed on the top of the trans at any time? That could cause water in the oil. I once got water in my trans when a hatch over the engine leaked. Checked the oil (ATF) and it looked like a strawberry milkshake.
So it is possible that the water got in there over time and no service has been done by the previous owner. I ended up draining the old milky water, filling it up with a solution of oil and seafiam, running it for a few minutes, draining and putting new oil in. After that I ran it in reverse and forward, drained, and repeated about 2 times. Filled it back up, no more leaks, well ad long as the level is perfect. If its overfilled it will slowly leak, maybe it was designed that way, or maybe the input shaft seal is shot, since it only leaks when the shaft is spinning. While getting all this done I used some uv dye in the coolant and the oil and tracked down a coolant leak and fixed that. All good for now. Decided to take her out, she stalled on me 5 feet from the slip and the starter just went on grinding. Took it apart, and the starter took a crap. Great. I hate boats.
So I figured it all out and most likely my input shaft seal is leaking at the front of the transmission. Anyone had the pleasure of replacing it?
Yanmar 2gm20 w/ Kansake KM2A requires SAE30 motor oil. ATF will ruin it
