YM1500 Trans vent leaking

[mjanselmo-HT]

All of a sudden the vent hole on the bottom of the transmission is leaking all the fluid out of it running or not. What seal has gone out, or does something else need to be cleaned? I've search all over on here and can't find any results.

 

[Norm-HT]

The only vent hole should be in the bell housing which connects the engine to the trans. There is normally a rubber plug in it. Any oil in there could be coming from the front trans. seal or the rear engine seal. I would just let all of the oil drain and see if it stops draining. Could be just an accumulation of 30+ years of minor seepage. The repair is a major job for the novice.

 

[winston-HT]

I don't believe there is a vent hole in the bottom of the transmission. If it is the vent hole in the clutch housing it could either be motor oil or hydraulic/transmission fluid. You should be able to tell the difference.

You might check your crankcase vent making sure it is not stopped up. #33 here. <LINK_TEXT text="http://www.hoyetra...HTE&amp;Category_Code=YM1500BLOCK</LINK_TEXT>

Also the transmission vent. #8 here <LINK_TEXT text="http://www.hoyetra...Y&amp;Category_Code=YM1500HYDLIFT</LINK_TEXT>

Norm beat me to it.

 

[mjanselmo-HT]

Its trans/hyd fluid for sure, it won't stay in the trans. There's an open hole in the bottom of the trans that is not threaded and has paint on the inside (which tells me it's supposed to be open or there was a plug before). I have owned the tractor for years and never had a problem, and never noticed the hole until hyd/trans started draining out of it. I put a rubber stopper in it and it started leaking out the front bell housing. There's no read on the dip stick anymore, and can’t fill up the trans without it running out the bottom hole (if it's unplugged) or the front when it's running.

I'll check the trans vent #8, maybe it's plugged and blowing out the front now. The plug on the bottom and the clogged vent could have been a coincidence.

 

[Norm-HT]

I certainly have never heard of a vent hole in the bottom of any Yanmar transmission, and can't imagine how it could work.

 

[winston-HT]

This is the bell/clutch housing. <LINK_TEXT text="http://www.hoyetra...GY&amp;Category_Code=YM1500CLUTCH</LINK_TEXT> This is the transmission housing. <LINK_TEXT text="http://www.hoyetra...mp;Category_Code=YM1500GTRANSCASE</LINK_TEXT>

 

[mjanselmo-HT]

Alright I have figured more out from the service manual.

The vent under the seat is clear
The two axle vents are clear
The long metal trans/hydro filter is clean

I have learned that where the leak was coming from is the drain hole on the long "bellhousing" between the trans and the engine. I would imagine the main shaft seal on the front of the trans is leaking and coming out the drain hole from the bottom of the bellhousing. Confirm if that sounds right?

Next question is I can't find where to purchase that seal. Looks pretty simple to replace; just looking through the service manual. I can't find a replacement on Hoye or anywhere else on the web. Anyone have experience with this?

 

[SDgray-HT]

That sounds right-wondering if the seal has popped out of it's housing-with just wear over the years,shouldn't be leaking that bad i would think...I looked at my 1500 since it is apart for engine repair,and there is no dimensions printed on the seal like many metric seals have-just an OEM part # Will be a cinch to change that seal once you get the tractor apart to reach it.Check the driveshaft coupler when apart-that is a wear item on these tractors,mine was nearly stripped.

 

[mjanselmo-HT]

Good to know...thank you

 

[Norm-HT]

How did you determine it was the trans. seal? Hoye has all seals.