Need to change transmission fluid

[MaryC]

I need to change my transmission fluid, as it's milky white. I have a 19 hp Yanwar on my 1996 Hunter 280. I'm not sure what I'm supposed to replace it with.

I'm also planning to change the oil. Ideas on what I should use? Is there some special oil for diesel engines? Also, how many quarts should it take.

Thanks,

Mary

 

[Don S/V ILLusion]

You need someone to tell you what transmission you have - hopefully someone else here knows which one was put on the 28 as some transmission use trans oil and others use engine oil. Also, unless you like doing this frequently, it's essential you find out why you are getting water into the transmission and repair the seal.

If you have the model no.of the trans, let us know and we can tell you what oil to use.

 

[Don S/V ILLusion]

just found the link for you once you id tranny
http://www.yanmarhelp.com/i_box2.htm

 

[MaryC]

How do I find which type

Any ideas on how I find which type of transmission I have?

 

[Don S/V ILLusion]

Re: How do I find which type

I should have said this before - look on the back of the transmission where the shaft connects - on the rear casing of the transmission, there is a plate on which you should be able to read the type.

 

[Clark]

I have a 1996 280 w/ the 2GM20F and my tranny takes . .

- according to the manual - whatever oil is used in the engine. I did vary a bit and put in 30W instead of 20W-40 that I put in the engine. If you'd like better confirmation, I can check my manual and give exact specs/capacities. I'm pretty sure it is the Kanzaki KM2P and takes 300 ml ; .3 L or ~10 oz. of oil. The dip stick is kinda odd; the proper level is right at the bottom of the stick. I'd also wonder why the oil is milky white?!

As to engine oil, any good quality oil rated for diesel use is fine. It'll state that right on the bottle. Make the weight selection based on your normal seasonal temps; 30W, 20W-40, etc.

By all means, check the plate on the transmission to make absolutely sure it is of that model.

 

[Mark14985]

You may need help!

Mary, milky white is a bad sign! The oil in your transmisssion is just that oil - not like a car that has transmission fluid. If it is milky white you may have water in your transmission.

 

[Clark]

Yea, I thought of water as well when I raised that flag.

But how in the world would water get into the transmission unless someone added it??

 

[Seattle Scott]

On the engine oil capacity, it really doens't matter how much it holds, what matters is how much you can remove during the oil change, thats how much you replace, then top off

 

[Ken13559]

I've asked a Yanmar asst service manager about oil for my KM2P gearbox on 2GM20F engine and he said to use same oil as the crankcase, which is 15W40. So I suppose, whatever you put in your crankcase (depending on local weather) that might just do for your gearbox.

 

[BillRoosa]

Two schools of thought

The engine oil is NOT an extreme pressure lubricant that gears need. that is why they make transmission fluid and put it in manual gearboxes. With that said, a lot of folks put engine oil in the gear box and get away with it. My manufacturer even recommends it!!!

I put 80 weight trans (not auto trans) fluid in all mine and they work great.

Since the engine and trans are separated from each other and the nastys from combustion can't get to the trans oil why are you changing it??

Oil does not wear out BTW, it get contaminated with combustion products. As long as the fluid level is where it should be (check for tilt) you should NEVER need to change the transmission oil. In fact oil that has been used actually works better as it has all the "rough edges" worn off.

You will see a microscopic decrease in your fuel mileage (knotage?) as 80 weight has more viscosity than your standard motor oil. But your gearbox will last forever.

 

[Don Crowther]

I disagree with you Bill Roosa

"The engine oil is NOT an extreme pressure lubricant that gears need. that is why they make transmission fluid and put it in manual gearboxes. With that said, a lot of folks put engine oil in the gear box and get away with it. My manufacturer even recommends it!!!"

I can't think of anything else that has more extreme pressure than a diesel engine. Yes transmissions work hard but not that hard in this installation.

That being said when I call my rep he said to use straight 30 wt. oil in the transmission.

Mary also said that the oil in the transmission was milky. Obviously there's water in there. I would say change it for now and check it regularly and if the water reappears then go looking for trouble

IMHO
Don
S/V Nauti-Nauti

 

[Nelsonhow@netscape.net]

Water in Trans.

White or coffee colored transmission oil means there is water in the oil.

There are only 2 ways that I can think that water will get into a Yanmar transmission. Either the rear end of the transmission (by the shaft) of the bottom of the motor was under water and water seeped past the oil seal, or the casing where is joins the engine block and you had a lot of water in the bilge, or someone bu water in there by mistake when they were adding water to the heat exchanger (assuming you have a fresh water system). I had the problem a long time ago when I hot about 8" of water in my boat from a leaking bolt on the skeg...(long story). But the water in the transmission resulted in slipping and the need to have the transmission rebuild. Not fun.

I would suggest that you QUICKLY drain the old fluid (oil) out, I think there's a plug on the lower part of the transmission housing and put in fresh fluid (oil) . Run the engine in all gears fowrard, neutral and reverse, for a while and change it again... I'd do this a few times and you might save yourself from a transmission job.

Good luck